feat(hub): add TRUSTED_PROXY_IPS allowlist for TRUSTED_AUTH_HEADER (#2327)

With TRUSTED_AUTH_HEADER set, the hub authenticates a request from the
header alone, whichever address it comes from. That is right when every
request passes through the reverse proxy, and not when the hub can also
be reached directly: anyone who can reach it sets the header themselves.

TRUSTED_PROXY_IPS takes a comma-separated list of IPs or CIDR ranges.
When set, the header is only honored on requests whose peer address is
in the list; other requests fall through to the normal authentication.
When unset, nothing changes.

The check uses the connection's RemoteAddr, not a forwarded header, so
the list names the proxy itself. IPv4-mapped IPv6 entries are treated as
IPv4. Entries that do not parse are skipped with a warning on the
console; a list with no valid entry trusts nobody, so a typo narrows the
allowlist instead of widening it.

.github/workflows/helm-charts.yml

@@ -63,7 +63,7 @@ jobs:
         uses: actions/checkout@v7
 
       - name: Set up Helm
-        uses: azure/setup-helm@v4
+        uses: azure/setup-helm@v5
 
       - name: Lint chart
         run: helm lint "${{ matrix.chart.path }}" --set env.KEY=ci-placeholder

SECURITY.md

@@ -2,6 +2,8 @@
 
 ## Reporting a Vulnerability
 
-If you find a vulnerability in the latest version, please [submit a private advisory](https://github.com/henrygd/beszel/security/advisories/new).
+**PLEASE ONLY USE SECURITY ADVISORIES FOR REAL HIGH SEVERITY VULNERABILITIES.**
 
-If it's low severity (use best judgement) you may open an issue instead of an advisory.
+If you find a vulnerability in the latest version, and it is not high severity, open an issue instead of an advisory.
+
+I am overwhelmed with advisories, often erroneous, which are clearly found and written by AI. I don't have the capacity to review all of them.

agent/agent.go

@@ -48,6 +48,7 @@ type Agent struct {
 	keys                      []gossh.PublicKey                                     // SSH public keys
 	smartManager              *SmartManager                                         // Manages SMART data
 	systemdManager            *systemdManager                                       // Manages systemd services
+	storagePoolManager        *StoragePoolManager                                   // Manages storage pool and dataset data
 }
 
 // NewAgent creates a new agent with the given data directory for persisting data.
@@ -121,6 +122,19 @@ func NewAgent(dataDir ...string) (agent *Agent, err error) {
 	// initialize handler registry
 	agent.handlerRegistry = NewHandlerRegistry()
 
+	agent.storagePoolManager = newStoragePoolManager()
+
+	// Retain ZFS_INTERVAL for the shared storage pool detail refresh interval.
+	if zfsIntervalEnv, exists := utils.GetEnv("ZFS_INTERVAL"); exists {
+		if duration, err := time.ParseDuration(zfsIntervalEnv); err == nil && duration > 0 {
+			agent.storagePoolManager.detailInterval = duration
+			agent.systemDetails.ZfsInterval = duration
+			slog.Info("ZFS_INTERVAL", "duration", duration)
+		} else {
+			slog.Warn("Invalid ZFS_INTERVAL", "err", err)
+		}
+	}
+
 	// initialize disk info
 	agent.initializeDiskInfo()
 
@@ -187,13 +201,25 @@ func (a *Agent) gatherStats(options common.DataRequestOptions) *system.CombinedD
 		}
 		if a.systemdManager.hasFreshStats {
 			data.SystemdServices = a.systemdManager.getServiceStats(nil, false)
+			data.SystemdServicesUpdated = true
+			// Preserve an explicit zero count so the hub can distinguish a fresh
+			// empty snapshot from a response that omitted systemd data.
+			if totalCount == 0 {
+				data.Info.Services = []uint16{0, 0}
+			}
 		}
 	}
 
 	data.Stats.ExtraFs = make(map[string]*system.FsStats)
 	data.Info.ExtraFsPct = make(map[string]float64)
 	for name, stats := range a.fsStats {
-		if !stats.Root && stats.DiskTotal > 0 {
+		if stats.Root {
+			if stats.Name != "" {
+				data.Info.RootDiskName = stats.Name
+			}
+			continue
+		}
+		if stats.DiskTotal > 0 {
 			// Use custom name if available, otherwise use device name
 			key := name
 			if stats.Name != "" {

agent/battery/battery.go

@@ -33,7 +33,10 @@ var errNoBatteries = errors.New("no readable batteries")
 func normalizeBatteries(batteries []Battery) []Battery {
 	nameCounts := make(map[string]int, len(batteries))
 	for i := range batteries {
-		name := strings.TrimSpace(batteries[i].Name)
+		// Names come from firmware (e.g. sysfs model_name) and are not guaranteed to
+		// be valid UTF-8. Invalid bytes are rejected when the hub decodes the CBOR
+		// payload, which drops every metric for the system, so strip them here.
+		name := strings.TrimSpace(strings.ToValidUTF8(batteries[i].Name, ""))
 		if name == "" {
 			name = "Battery " + strconv.Itoa(i+1)
 		}

agent/battery/battery_test.go

@@ -2,6 +2,7 @@ package battery
 
 import (
 	"testing"
+	"unicode/utf8"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -33,3 +34,15 @@ func TestNormalizeBatteriesFallbackNames(t *testing.T) {
 	bats := normalizeBatteries([]Battery{{}, {}, {Name: "Mouse"}, {Name: "Mouse"}})
 	assert.Equal(t, []string{"Battery 1", "Battery 2", "Mouse", "Mouse (2)"}, []string{bats[0].Name, bats[1].Name, bats[2].Name, bats[3].Name})
 }
+
+func TestNormalizeBatteriesStripsInvalidUTF8(t *testing.T) {
+	// Firmware occasionally reports names that are not valid UTF-8 (a ThinkPad
+	// reporting "LNV-5B11K63024@\xd0" in model_name is a real example).
+	bats := normalizeBatteries([]Battery{{Name: "LNV-5B11K63024@\xd0"}, {Name: "\xff\xfe"}})
+	assert.Equal(t, "LNV-5B11K63024@", bats[0].Name)
+	// A name made up entirely of invalid bytes falls back to the generic name.
+	assert.Equal(t, "Battery 2", bats[1].Name)
+	for _, b := range bats {
+		assert.True(t, utf8.ValidString(b.Name))
+	}
+}

agent/btrfs/btrfs.go

@@ -0,0 +1,26 @@
+// Package btrfs reads btrfs filesystem state from sysfs.
+package btrfs
+
+// Filesystem is a mounted btrfs filesystem read from /sys/fs/btrfs/<uuid>.
+type Filesystem struct {
+	UUID     string // stable filesystem UUID from sysfs
+	MountID  string // kernel filesystem identity for matching monitored mounts
+	IODevice string // sole member block-device name, empty for multi-device/unknown pools
+	Name     string // label, else first mountpoint, else UUID
+	Size     uint64 // effective usable capacity, or raw member capacity when Raw
+	Raw      bool   // capacity and usage are physical bytes, unsuitable for disk alerts
+	Alloc    uint64 // raw bytes allocated to data, metadata and system chunks
+	Health   string // ONLINE, or DEGRADED when a device is missing
+	NRead    uint64 // cumulative bytes read across member devices
+	NWrite   uint64 // cumulative bytes written across member devices
+	Devices  []Device
+}
+
+// Device is one member device (devinfo/<devid>) with its error counters.
+type Device struct {
+	Name           string // "devid N"; sysfs does not expose the block device path
+	State          string // ONLINE or MISSING
+	ReadErrs       uint64
+	WriteErrs      uint64
+	CorruptionErrs uint64
+}

agent/btrfs/btrfs_linux.go

@@ -0,0 +1,285 @@
+//go:build linux
+
+package btrfs
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"unsafe"
+
+	"github.com/henrygd/beszel/agent/utils"
+	"golang.org/x/sys/unix"
+)
+
+var (
+	sysfsPath       = "/sys/fs/btrfs"
+	mountsPath      = "/proc/self/mounts"
+	mountinfoPath   = "/proc/self/mountinfo"
+	mountUUID       = MountID
+	deviceSize      = ioctlDeviceSize
+	filesystemUsage = statfsUsage
+)
+
+// Filesystems returns all mounted btrfs filesystems, or nil when there are none.
+func Filesystems() ([]Filesystem, error) {
+	entries, err := os.ReadDir(sysfsPath)
+	if errors.Is(err, os.ErrNotExist) {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	mounts := mountpointsByDevice()
+	var filesystems []Filesystem
+	for _, entry := range entries {
+		if !entry.IsDir() || entry.Name() == "features" {
+			continue
+		}
+		fs, err := readFilesystem(filepath.Join(sysfsPath, entry.Name()), mounts)
+		if err != nil {
+			return nil, fmt.Errorf("btrfs %s: %w", entry.Name(), err)
+		}
+		filesystems = append(filesystems, fs)
+	}
+	return filesystems, nil
+}
+
+func readFilesystem(dir string, mounts map[string]string) (Filesystem, error) {
+	fs := Filesystem{UUID: filepath.Base(dir), Name: utils.ReadStringFile(filepath.Join(dir, "label")), Health: "UNKNOWN"}
+	for _, kind := range []string{"data", "metadata", "system"} {
+		if value, ok := utils.ReadUintFile(filepath.Join(dir, "allocation", kind, "disk_used")); ok {
+			fs.Alloc += value
+		}
+	}
+	// devices/<name> links to the block device's sysfs directory.
+	devices, err := os.ReadDir(filepath.Join(dir, "devices"))
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return fs, err
+	}
+	mountpoint := mounts["uuid:"+fs.UUID]
+	if fs.Name == "" {
+		fs.Name = mountpoint
+	}
+	var backingSize uint64
+	for _, dev := range devices {
+		if mountpoint == "" {
+			mountpoint = mounts[dev.Name()]
+		}
+		if fs.Name == "" {
+			fs.Name = mountpoint
+		}
+		devDir := filepath.Join(dir, "devices", dev.Name())
+		if size, ok := utils.ReadUintFile(filepath.Join(devDir, "size")); ok {
+			backingSize += size * 512
+		}
+		if stat := strings.Fields(utils.ReadStringFile(filepath.Join(devDir, "stat"))); len(stat) >= 7 {
+			fs.NRead += parseUint(stat[2]) * 512
+			fs.NWrite += parseUint(stat[6]) * 512
+		}
+	}
+	devids, err := os.ReadDir(filepath.Join(dir, "devinfo"))
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return fs, err
+	}
+	capacityAvailable := len(devids) > 0
+	healthKnown := len(devids) > 0
+	for _, devid := range devids {
+		devDir := filepath.Join(dir, "devinfo", devid.Name())
+		// Replacement targets do not add filesystem capacity.
+		replaceTarget, _ := utils.ReadUintFile(filepath.Join(devDir, "replace_target"))
+		if replaceTarget != 1 {
+			devid, err := strconv.ParseUint(devid.Name(), 10, 64)
+			if err != nil {
+				return fs, err
+			}
+			size, err := deviceSize(mountpoint, devid)
+			if err != nil {
+				capacityAvailable = false
+			}
+			fs.Size += size
+		}
+		dev := Device{Name: "devid " + devid.Name(), State: "ONLINE"}
+		missing := utils.ReadStringFile(filepath.Join(devDir, "missing"))
+		if missing != "0" && missing != "1" {
+			healthKnown = false
+			dev.State = "UNKNOWN"
+		}
+		if missing == "1" {
+			dev.State = "MISSING"
+			fs.Health = "DEGRADED"
+		}
+		for line := range strings.Lines(utils.ReadStringFile(filepath.Join(devDir, "error_stats"))) {
+			if fields := strings.Fields(line); len(fields) == 2 {
+				switch fields[0] {
+				case "read_errs":
+					dev.ReadErrs = parseUint(fields[1])
+				case "write_errs":
+					dev.WriteErrs = parseUint(fields[1])
+				case "corruption_errs":
+					dev.CorruptionErrs = parseUint(fields[1])
+				}
+			}
+		}
+		fs.Devices = append(fs.Devices, dev)
+	}
+	// Use one capacity source for the whole filesystem: device IDs cannot be
+	// reliably matched to block-device names in sysfs. A partial ioctl result
+	// must not be added to the complete backing-device total.
+	if !capacityAvailable {
+		fs.Size = backingSize
+	}
+	if fs.Health != "DEGRADED" && healthKnown {
+		fs.Health = "ONLINE"
+	}
+	fs.MountID = mountUUID(mountpoint)
+	if len(devices) == 1 && len(devids) == 1 && fs.Health == "ONLINE" {
+		fs.IODevice = devices[0].Name()
+	}
+	fs.Raw = true
+	if used, available, err := filesystemUsage(mountpoint); err == nil {
+		// Effective capacity excludes reserved/unavailable space, so Size-Alloc
+		// is available to applications and the usage ratio matches df.
+		fs.Size, fs.Alloc, fs.Raw = used+available, used, false
+	}
+	if fs.Name == "" {
+		fs.Name = filepath.Base(dir)
+	}
+	return fs, nil
+}
+
+// mountpointsByDevice prefers UUID matches from mountinfo and retains source
+// device names as a fallback for environments where FS_INFO is unavailable.
+func mountpointsByDevice() map[string]string {
+	mounts := mountpointsByUUID(utils.ReadStringFile(mountinfoPath), mountUUID)
+	for line := range strings.Lines(utils.ReadStringFile(mountsPath)) {
+		fields := strings.Fields(line)
+		if len(fields) < 3 || fields[2] != "btrfs" {
+			continue
+		}
+		device := fields[0]
+		if resolved, err := filepath.EvalSymlinks(device); err == nil {
+			device = resolved
+		}
+		if _, seen := mounts[filepath.Base(device)]; !seen {
+			mounts[filepath.Base(device)] = unescapeMountPath(fields[1])
+		}
+	}
+	return mounts
+}
+
+func parseUint(s string) uint64 {
+	n, _ := strconv.ParseUint(s, 10, 64)
+	return n
+}
+
+// ioctlDeviceSize reads Btrfs's recorded device size, which can be smaller
+// than the block device after a filesystem resize. BTRFS_IOC_DEV_INFO is
+// _IOWR(0x94, 30, struct btrfs_ioctl_dev_info_args), a 4096-byte ABI structure.
+func ioctlDeviceSize(mountpoint string, devid uint64) (uint64, error) {
+	if mountpoint == "" {
+		return 0, errors.New("no accessible mountpoint")
+	}
+	f, err := os.Open(mountpoint)
+	if err != nil {
+		return 0, err
+	}
+	defer f.Close()
+	args := struct {
+		Devid      uint64
+		UUID       [16]byte
+		BytesUsed  uint64
+		TotalBytes uint64
+		Reserved   [4096 - 40]byte
+	}{Devid: devid}
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, f.Fd(), 0xd000941e, uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return 0, errno
+	}
+	return args.TotalBytes, nil
+}
+
+// The filesystem magic is unsigned even when Statfs_t.Type is int32.
+func isBtrfs(stat *unix.Statfs_t) bool {
+	return uint32(stat.Type) == unix.BTRFS_SUPER_MAGIC
+}
+
+func statfsUsage(path string) (used, available uint64, err error) {
+	if path == "" {
+		return 0, 0, errors.New("no accessible mountpoint")
+	}
+	var stat unix.Statfs_t
+	if err = unix.Statfs(path, &stat); err != nil {
+		return
+	}
+	if !isBtrfs(&stat) {
+		return 0, 0, errors.New("mountpoint is not Btrfs")
+	}
+	blockSize := uint64(stat.Bsize)
+	return (stat.Blocks - min(stat.Blocks, stat.Bfree)) * blockSize, min(stat.Blocks, stat.Bavail) * blockSize, nil
+}
+
+// MountID returns the filesystem UUID via BTRFS_IOC_FS_INFO. Unlike statfs
+// f_fsid, this identity is shared by all subvolumes and bind mounts.
+func MountID(path string) string {
+	if path == "" {
+		return ""
+	}
+	var stat unix.Statfs_t
+	if unix.Statfs(path, &stat) != nil || !isBtrfs(&stat) {
+		return ""
+	}
+	f, err := os.Open(path)
+	if err != nil {
+		return ""
+	}
+	defer f.Close()
+	args := struct {
+		MaxID      uint64
+		NumDevices uint64
+		FSID       [16]byte
+		Reserved   [992]byte
+	}{}
+	// _IOR(0x94, 31, 1024). Reuse the platform's read-direction bits;
+	// MIPS/PowerPC use a different encoding than asm-generic.
+	request := uintptr(unix.FS_IOC_GETFLAGS&0xe0000000) | 0x0400941f
+	_, _, errno := unix.Syscall(unix.SYS_IOCTL, f.Fd(), request, uintptr(unsafe.Pointer(&args)))
+	if errno != 0 {
+		return ""
+	}
+	id := args.FSID
+	return fmt.Sprintf("%x-%x-%x-%x-%x", id[:4], id[4:6], id[6:8], id[8:10], id[10:])
+}
+
+// Btrfs mountinfo device numbers can be virtual (0:N), so query the UUID
+// through the mount instead of comparing those numbers with sysfs block devs.
+// Retry another path when a bind mount is inaccessible. Once resolved, reuse
+// the result for that mount device to avoid opening every Docker bind mount.
+func mountpointsByUUID(mountinfo string, identify func(string) string) map[string]string {
+	mounts := make(map[string]string)
+	resolved := make(map[string]bool)
+	for line := range strings.Lines(mountinfo) {
+		before, after, ok := strings.Cut(line, " - ")
+		fields, fs := strings.Fields(before), strings.Fields(after)
+		if !ok || len(fields) < 6 || len(fs) < 3 || fs[0] != "btrfs" || resolved[fields[2]] {
+			continue
+		}
+		path := unescapeMountPath(fields[4])
+		uuid := identify(path)
+		if uuid == "" {
+			continue
+		}
+		resolved[fields[2]] = true
+		if mounts["uuid:"+uuid] == "" {
+			mounts["uuid:"+uuid] = path
+		}
+	}
+	return mounts
+}
+
+func unescapeMountPath(path string) string {
+	return strings.NewReplacer(`\040`, " ", `\011`, "\t", `\012`, "\n", `\134`, `\`).Replace(path)
+}

agent/btrfs/btrfs_linux_test.go

@@ -0,0 +1,274 @@
+//go:build testing && linux
+
+package btrfs
+
+import (
+	"os"
+	"path/filepath"
+	"strconv"
+	"testing"
+
+	"github.com/henrygd/beszel/agent/utils"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/sys/unix"
+)
+
+func TestFilesystems(t *testing.T) {
+	root := t.TempDir()
+	oldSysfs, oldMounts := sysfsPath, mountsPath
+	sysfsPath, mountsPath = root, filepath.Join(root, "mounts")
+	t.Cleanup(func() { sysfsPath, mountsPath = oldSysfs, oldMounts })
+
+	fsDir := filepath.Join(root, "1b2c3d4e-0000-0000-0000-000000000000")
+	write := func(rel, content string) {
+		path := filepath.Join(fsDir, rel)
+		require.NoError(t, os.MkdirAll(filepath.Dir(path), 0o755))
+		require.NoError(t, os.WriteFile(path, []byte(content), 0o644))
+	}
+	require.NoError(t, os.MkdirAll(filepath.Join(root, "features"), 0o755))
+	oldUsage := filesystemUsage
+	filesystemUsage = func(string) (uint64, uint64, error) { return 0, 0, os.ErrNotExist }
+	t.Cleanup(func() { filesystemUsage = oldUsage })
+	oldDeviceSize := deviceSize
+	t.Cleanup(func() { deviceSize = oldDeviceSize })
+	deviceSize = func(_ string, devid uint64) (uint64, error) {
+		value, _ := utils.ReadUintFile(filepath.Join(fsDir, "recorded-size", strconv.FormatUint(devid, 10)))
+		return value, nil
+	}
+	// Recorded member capacities differ from the unchanged backing devices.
+	write("recorded-size/1", "256000\n")
+	write("recorded-size/2", "128000\n")
+	write("label", "tank\n")
+	write("allocation/data/disk_used", "4096\n")
+	write("allocation/metadata/disk_used", "2048\n")
+	write("allocation/system/disk_used", "1024\n")
+	write("devices/sda/size", "1000\n")
+	write("devices/sda/stat", "10 0 200 0 20 0 400 0 0 0 0\n")
+	write("devices/sdb/size", "1000\n")
+	write("devices/sdb/stat", "10 0 100 0 20 0 100 0 0 0 0\n")
+	write("devinfo/1/missing", "0\n")
+	write("devinfo/1/error_stats", "write_errs 1\nread_errs 2\nflush_errs 0\ncorruption_errs 3\ngeneration_errs 0\n")
+	write("devinfo/2/missing", "1\n")
+
+	filesystems, err := Filesystems()
+	require.NoError(t, err)
+	require.Len(t, filesystems, 1)
+	assert.Equal(t, Filesystem{
+		UUID: "1b2c3d4e-0000-0000-0000-000000000000", Raw: true, Name: "tank", Size: 384000, Alloc: 7168, Health: "DEGRADED", NRead: 153600, NWrite: 256000,
+		Devices: []Device{
+			{Name: "devid 1", State: "ONLINE", ReadErrs: 2, WriteErrs: 1, CorruptionErrs: 3},
+			{Name: "devid 2", State: "MISSING"},
+		},
+	}, filesystems[0])
+
+	// Unlabeled filesystems fall back to the first mountpoint, then the UUID.
+	write("label", "\n")
+	require.NoError(t, os.WriteFile(mountsPath, []byte(
+		"/dev/sdz1 /other btrfs rw 0 0\n/dev/sdb /mnt/storage btrfs rw 0 0\n/dev/sdb /mnt/storage/sub btrfs rw,subvol=/sub 0 0\n",
+	), 0o644))
+	filesystems, err = Filesystems()
+	require.NoError(t, err)
+	assert.Equal(t, "/mnt/storage", filesystems[0].Name)
+
+	require.NoError(t, os.Remove(mountsPath))
+	filesystems, err = Filesystems()
+	require.NoError(t, err)
+	assert.Equal(t, "1b2c3d4e-0000-0000-0000-000000000000", filesystems[0].Name)
+	write("devinfo/3/replace_target", "1\n")
+	write("recorded-size/3", "512000\n")
+	filesystems, err = Filesystems()
+	require.NoError(t, err)
+	assert.Equal(t, uint64(384000), filesystems[0].Size, "replacement target must not inflate capacity")
+
+	deviceSize = func(string, uint64) (uint64, error) { return 0, os.ErrPermission }
+	filesystems, err = Filesystems()
+	require.NoError(t, err)
+	require.Len(t, filesystems, 1)
+	assert.Equal(t, uint64(1024000), filesystems[0].Size)
+	assert.Equal(t, "DEGRADED", filesystems[0].Health)
+	assert.Equal(t, uint64(153600), filesystems[0].NRead)
+
+	// A partial ioctl result must not be mixed with the backing-device total.
+	deviceSize = func(_ string, devid uint64) (uint64, error) {
+		if devid == 2 {
+			return 0, os.ErrPermission
+		}
+		return 256000, nil
+	}
+	filesystems, err = Filesystems()
+	require.NoError(t, err)
+	assert.Equal(t, uint64(1024000), filesystems[0].Size)
+
+	// With no mount visible (e.g. Docker), the real lookup falls back too.
+	deviceSize = ioctlDeviceSize
+	filesystems, err = Filesystems()
+	require.NoError(t, err)
+	require.Len(t, filesystems, 1)
+	assert.Equal(t, uint64(1024000), filesystems[0].Size)
+
+	filesystemUsage = func(string) (uint64, uint64, error) { return 100, 900, nil }
+	filesystems, err = Filesystems()
+	require.NoError(t, err)
+	assert.Equal(t, uint64(1000), filesystems[0].Size)
+	assert.Equal(t, uint64(100), filesystems[0].Alloc)
+	assert.False(t, filesystems[0].Raw)
+}
+
+func TestFilesystemsNoBtrfs(t *testing.T) {
+	oldPath := sysfsPath
+	sysfsPath = filepath.Join(t.TempDir(), "missing")
+	t.Cleanup(func() { sysfsPath = oldPath })
+
+	filesystems, err := Filesystems()
+	require.NoError(t, err)
+	assert.Nil(t, filesystems)
+}
+
+func TestIoctlDeviceSizeFailure(t *testing.T) {
+	_, err := ioctlDeviceSize("", 1)
+	require.Error(t, err)
+	_, err = ioctlDeviceSize(t.TempDir(), 1)
+	require.Error(t, err)
+	assert.ErrorIs(t, err, unix.ENOTTY)
+}
+
+func TestMountpointsDecodeEscapes(t *testing.T) {
+	oldMounts := mountsPath
+	mountsPath = filepath.Join(t.TempDir(), "mounts")
+	t.Cleanup(func() { mountsPath = oldMounts })
+	require.NoError(t, os.WriteFile(mountsPath, []byte("/dev/test-btrfs /mnt/my\\040data btrfs rw 0 0\n"), 0o644))
+	assert.Equal(t, "/mnt/my data", mountpointsByDevice()["test-btrfs"])
+}
+
+func TestFilesystemWithoutDevinfo(t *testing.T) {
+	root := t.TempDir()
+	require.NoError(t, os.MkdirAll(filepath.Join(root, "devices", "sda"), 0755))
+	require.NoError(t, os.WriteFile(filepath.Join(root, "devices", "sda", "size"), []byte("1000"), 0644))
+	fs, err := readFilesystem(root, nil)
+	require.NoError(t, err)
+	assert.Equal(t, uint64(512000), fs.Size)
+	assert.True(t, fs.Raw)
+	assert.Equal(t, "UNKNOWN", fs.Health)
+	assert.Empty(t, fs.Devices)
+
+	require.NoError(t, os.MkdirAll(filepath.Join(root, "devinfo", "1"), 0755))
+	fs, err = readFilesystem(root, nil)
+	require.NoError(t, err)
+	assert.Equal(t, "UNKNOWN", fs.Health)
+	require.Len(t, fs.Devices, 1)
+	assert.Equal(t, "UNKNOWN", fs.Devices[0].State)
+
+	// Some older interfaces lack the devices directory too.
+	fs, err = readFilesystem(t.TempDir(), nil)
+	require.NoError(t, err)
+	assert.Equal(t, "UNKNOWN", fs.Health)
+}
+
+func TestLocalBtrfsUsage(t *testing.T) {
+	path := os.Getenv("BESZEL_TEST_BTRFS_MOUNT")
+	if path == "" {
+		t.Skip("set BESZEL_TEST_BTRFS_MOUNT for read-only live validation")
+	}
+	used, available, err := statfsUsage(path)
+	require.NoError(t, err)
+	filesystems, err := Filesystems()
+	require.NoError(t, err)
+	for _, fs := range filesystems {
+		if !fs.Raw && fs.Alloc == used && fs.Size == used+available {
+			t.Logf("pool=%s used=%d available=%d effective_capacity=%d", fs.Name, used, available, fs.Size)
+			return
+		}
+	}
+	t.Fatal("collector did not report the mounted filesystem's usable capacity")
+}
+
+func TestMountID(t *testing.T) {
+	assert.Empty(t, MountID(""))
+	assert.Empty(t, MountID(filepath.Join(t.TempDir(), "missing")))
+	path := os.Getenv("BESZEL_TEST_BTRFS_MOUNT")
+	if path == "" {
+		t.Skip("set BESZEL_TEST_BTRFS_MOUNT for live identity validation")
+	}
+	id := MountID(path)
+	require.NotEmpty(t, id)
+	assert.Equal(t, id, MountID(filepath.Join(path, ".")))
+}
+
+func TestMountinfoUUIDLookup(t *testing.T) {
+	info := `1 0 0:40 /@ /inaccessible ro shared:1 - btrfs /dev/mapper/unavailable rw
+2 0 0:40 /@/docker/hosts /etc/hosts ro - btrfs /dev/mapper/unavailable rw
+3 0 0:40 /@/docker/hostname /etc/hostname ro - btrfs /dev/mapper/unavailable rw
+4 0 0:41 /subvol /extra-filesystems/my\040disk ro master:2 - btrfs /dev/missing rw
+5 0 0:42 / /ext4 ro - ext4 /dev/mapper/unavailable rw
+malformed
+6 0 0:43 / /bad ro - btrfs
+`
+	var calls []string
+	mounts := mountpointsByUUID(info, func(path string) string {
+		calls = append(calls, path)
+		switch path {
+		case "/etc/hosts":
+			return "root-uuid"
+		case "/extra-filesystems/my disk":
+			return "extra-uuid"
+		}
+		return ""
+	})
+	assert.Equal(t, map[string]string{"uuid:root-uuid": "/etc/hosts", "uuid:extra-uuid": "/extra-filesystems/my disk"}, mounts)
+	assert.Equal(t, []string{"/inaccessible", "/etc/hosts", "/extra-filesystems/my disk"}, calls)
+}
+
+func TestDockerFilesystemWithoutDeviceNodes(t *testing.T) {
+	root := t.TempDir()
+	oldSysfs, oldMounts, oldInfo, oldUUID, oldUsage := sysfsPath, mountsPath, mountinfoPath, mountUUID, filesystemUsage
+	t.Cleanup(func() {
+		sysfsPath, mountsPath, mountinfoPath, mountUUID, filesystemUsage = oldSysfs, oldMounts, oldInfo, oldUUID, oldUsage
+	})
+	sysfsPath = filepath.Join(root, "sysfs")
+	mountsPath = filepath.Join(root, "missing-mounts")
+	mountinfoPath = filepath.Join(root, "mountinfo")
+	uuid := "11111111-1111-4111-8111-111111111111"
+	dir := filepath.Join(sysfsPath, uuid)
+	for path, content := range map[string]string{"devices/dm-0/size": "1000", "devinfo/1/missing": "0"} {
+		target := filepath.Join(dir, path)
+		require.NoError(t, os.MkdirAll(filepath.Dir(target), 0755))
+		require.NoError(t, os.WriteFile(target, []byte(content), 0644))
+	}
+	require.NoError(t, os.WriteFile(mountinfoPath, []byte("2 1 0:40 /@/docker/hosts /etc/hosts ro - btrfs /dev/mapper/not-in-container rw\n"), 0644))
+	mountUUID = func(path string) string {
+		if path == "/etc/hosts" {
+			return uuid
+		}
+		return ""
+	}
+	filesystemUsage = func(path string) (uint64, uint64, error) { require.Equal(t, "/etc/hosts", path); return 100, 900, nil }
+	fs, err := Filesystems()
+	require.NoError(t, err)
+	require.Len(t, fs, 1)
+	assert.Equal(t, uuid, fs[0].MountID)
+	assert.Equal(t, "dm-0", fs[0].IODevice)
+	assert.False(t, fs[0].Raw)
+	assert.Equal(t, uint64(1000), fs[0].Size)
+}
+
+func TestLivePoolMountIdentity(t *testing.T) {
+	path := os.Getenv("BESZEL_TEST_BTRFS_MOUNT")
+	if path == "" {
+		t.Skip("set BESZEL_TEST_BTRFS_MOUNT for live validation")
+	}
+	id := MountID(path)
+	require.NotEmpty(t, id)
+	pools, err := Filesystems()
+	require.NoError(t, err)
+	for _, pool := range pools {
+		if pool.UUID != id {
+			continue
+		}
+		assert.Equal(t, id, pool.MountID)
+		assert.False(t, pool.Raw)
+		t.Logf("uuid=%s mount_identity=%s io_device=%s raw=%v", pool.UUID, pool.MountID, pool.IODevice, pool.Raw)
+		return
+	}
+	t.Fatal("mounted Btrfs filesystem was not discovered")
+}

agent/btrfs/btrfs_unsupported.go

@@ -0,0 +1,11 @@
+//go:build !linux
+
+package btrfs
+
+import "errors"
+
+func Filesystems() ([]Filesystem, error) {
+	return nil, errors.ErrUnsupported
+}
+
+func MountID(string) string { return "" }

agent/client.go

@@ -2,6 +2,7 @@ package agent
 
 import (
 	"crypto/tls"
+	"crypto/x509"
 	"errors"
 	"fmt"
 	"log/slog"
@@ -24,9 +25,28 @@ import (
 )
 
 const (
-	wsDeadline = 70 * time.Second
+	// Keep the connection alive long enough for a slow collection cycle to
+	// finish before the hub considers the agent disconnected.
+	wsDeadline = 120 * time.Second
 )
 
+// errNoHubURL is returned when HUB_URL is unset. This is not a failure
+// condition: an agent configured with only a public key runs in SSH-only mode,
+// where the hub dials the agent and no outbound WebSocket client is expected.
+var errNoHubURL = errors.New("HUB_URL environment variable not set")
+
+type caCertFileError struct {
+	err error
+}
+
+func (e *caCertFileError) Error() string {
+	return e.err.Error()
+}
+
+func (e *caCertFileError) Unwrap() error {
+	return e.err
+}
+
 // WebSocketClient manages the WebSocket connection between the agent and hub.
 // It handles authentication, message routing, and connection lifecycle management.
 type WebSocketClient struct {
@@ -40,6 +60,7 @@ type WebSocketClient struct {
 	hubRequest         *common.HubRequest[cbor.RawMessage] // Reusable request structure for message parsing
 	lastConnectAttempt time.Time                           // Timestamp of last connection attempt
 	hubVerified        bool                                // Whether the hub has been cryptographically verified
+	tlsConfig          *tls.Config                         // Optional TLS configuration with custom CA certificates
 }
 
 // newWebSocketClient creates a new WebSocket client for the given agent.
@@ -47,7 +68,7 @@ type WebSocketClient struct {
 func newWebSocketClient(agent *Agent) (client *WebSocketClient, err error) {
 	hubURLStr, exists := utils.GetEnv("HUB_URL")
 	if !exists {
-		return nil, errors.New("HUB_URL environment variable not set")
+		return nil, errNoHubURL
 	}
 
 	client = &WebSocketClient{}
@@ -61,6 +82,10 @@ func newWebSocketClient(agent *Agent) (client *WebSocketClient, err error) {
 	if err != nil {
 		return nil, err
 	}
+	client.tlsConfig, err = getTLSConfig()
+	if err != nil {
+		return nil, err
+	}
 
 	client.agent = agent
 	client.hubRequest = &common.HubRequest[cbor.RawMessage]{}
@@ -87,7 +112,52 @@ func getToken() (string, error) {
 	if err != nil {
 		return "", err
 	}
-	return strings.TrimSpace(string(tokenBytes)), nil
+	return parseTokenFile(string(tokenBytes), tokenFile)
+}
+
+// parseTokenFile reads a single token from TOKEN_FILE.
+// Blank lines and comments are ignored. Multiple tokens are rejected because
+// the agent supports only one outbound hub connection.
+func parseTokenFile(contents, path string) (string, error) {
+	var token string
+	for line := range strings.Lines(contents) {
+		line = strings.TrimSpace(line)
+		if len(line) == 0 || strings.HasPrefix(line, "#") {
+			continue
+		}
+		if token != "" {
+			return "", fmt.Errorf("%s must contain a single token", path)
+		}
+		token = line
+	}
+	// An empty file keeps returning an empty token, as before: the caller decides
+	// what to do about it.
+	return token, nil
+}
+
+// getTLSConfig returns a TLS configuration containing the system certificate
+// pool plus any certificates configured through CA_CERT_FILE. A nil config lets
+// gws use Go's default TLS configuration and system roots.
+func getTLSConfig() (*tls.Config, error) {
+	caCertFile, _ := utils.GetEnv("CA_CERT_FILE")
+	if caCertFile == "" {
+		return nil, nil
+	}
+
+	caCertPEM, err := os.ReadFile(caCertFile)
+	if err != nil {
+		return nil, &caCertFileError{fmt.Errorf("read CA_CERT_FILE %q: %w", caCertFile, err)}
+	}
+
+	rootCAs, err := x509.SystemCertPool()
+	if err != nil {
+		return nil, &caCertFileError{fmt.Errorf("load system CA certificate pool: %w", err)}
+	}
+	if !rootCAs.AppendCertsFromPEM(caCertPEM) {
+		return nil, &caCertFileError{fmt.Errorf("CA_CERT_FILE %q does not contain any valid PEM certificates", caCertFile)}
+	}
+
+	return &tls.Config{RootCAs: rootCAs}, nil
 }
 
 // getOptions returns the WebSocket client options, creating them if necessary.
@@ -112,7 +182,7 @@ func (client *WebSocketClient) getOptions() *gws.ClientOption {
 
 	client.options = &gws.ClientOption{
 		Addr:      client.hubURL.String(),
-		TlsConfig: &tls.Config{InsecureSkipVerify: true},
+		TlsConfig: client.tlsConfig,
 		RequestHeader: http.Header{
 			"User-Agent": []string{getUserAgent()},
 			"X-Token":    []string{client.token},

agent/client_test.go

@@ -4,8 +4,19 @@ package agent
 
 import (
 	"crypto/ed25519"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"math/big"
+	"net"
+	"net/http"
+	"net/http/httptest"
 	"net/url"
 	"os"
+	"path/filepath"
 	"strings"
 	"testing"
 	"time"
@@ -15,11 +26,34 @@ import (
 	"github.com/henrygd/beszel/internal/common"
 
 	"github.com/fxamacker/cbor/v2"
+	"github.com/lxzan/gws"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"golang.org/x/crypto/ssh"
 )
 
+// TestNewWebSocketClientNoHubURL verifies that an unset HUB_URL returns the
+// errNoHubURL sentinel rather than an opaque error. Callers rely on this to
+// distinguish SSH-only mode -- a supported configuration in which the hub dials
+// the agent -- from an actual misconfiguration.
+func TestNewWebSocketClientNoHubURL(t *testing.T) {
+	agent := createTestAgent(t)
+
+	// t.Setenv registers restoration of the original value; unset afterwards so
+	// GetEnv's LookupEnv reports the variable as absent rather than empty.
+	t.Setenv("BESZEL_AGENT_HUB_URL", "")
+	os.Unsetenv("BESZEL_AGENT_HUB_URL")
+	t.Setenv("HUB_URL", "")
+	os.Unsetenv("HUB_URL")
+	t.Setenv("BESZEL_AGENT_TOKEN", "test-token")
+
+	client, err := newWebSocketClient(agent)
+
+	require.Error(t, err)
+	assert.Nil(t, client)
+	assert.ErrorIs(t, err, errNoHubURL)
+}
+
 // TestNewWebSocketClient tests WebSocket client creation
 func TestNewWebSocketClient(t *testing.T) {
 	agent := createTestAgent(t)
@@ -164,6 +198,155 @@ func TestWebSocketClient_GetOptions(t *testing.T) {
 	}
 }
 
+func TestWebSocketClient_TLSVerification(t *testing.T) {
+	agent := createTestAgent(t)
+	serverCert, serverCertPEM := newSelfSignedServerCertificate(t)
+	upgrader := gws.NewUpgrader(&gws.BuiltinEventHandler{}, nil)
+	server := httptest.NewUnstartedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		conn, err := upgrader.Upgrade(w, r)
+		if err == nil {
+			go conn.ReadLoop()
+		}
+	}))
+	server.TLS = &tls.Config{Certificates: []tls.Certificate{serverCert}}
+	server.StartTLS()
+	t.Cleanup(server.Close)
+
+	caCertFile := filepath.Join(t.TempDir(), "hub-ca.crt")
+	require.NoError(t, os.WriteFile(caCertFile, serverCertPEM, 0600))
+
+	newClient := func(t *testing.T, caCertFile string) *WebSocketClient {
+		t.Helper()
+		t.Setenv("BESZEL_AGENT_HUB_URL", server.URL)
+		t.Setenv("BESZEL_AGENT_TOKEN", "test-token")
+		t.Setenv("BESZEL_AGENT_CA_CERT_FILE", caCertFile)
+		client, err := newWebSocketClient(agent)
+		require.NoError(t, err)
+		return client
+	}
+
+	t.Run("system roots are used by default", func(t *testing.T) {
+		client := newClient(t, "")
+		assert.Nil(t, client.getOptions().TlsConfig)
+		_, _, err := gws.NewClient(&gws.BuiltinEventHandler{}, client.getOptions())
+		require.Error(t, err)
+	})
+
+	t.Run("custom CA trusts self-signed certificate", func(t *testing.T) {
+		systemRoots, err := x509.SystemCertPool()
+		require.NoError(t, err)
+		client := newClient(t, caCertFile)
+		assert.Greater(t, len(client.getOptions().TlsConfig.RootCAs.Subjects()), len(systemRoots.Subjects()))
+		conn, _, err := gws.NewClient(&gws.BuiltinEventHandler{}, client.getOptions())
+		require.NoError(t, err)
+		require.NoError(t, conn.NetConn().Close())
+	})
+
+	t.Run("custom CA does not bypass hostname verification", func(t *testing.T) {
+		client := newClient(t, caCertFile)
+		client.getOptions().TlsConfig.ServerName = "wrong.example.com"
+		_, _, err := gws.NewClient(&gws.BuiltinEventHandler{}, client.getOptions())
+		require.Error(t, err)
+	})
+}
+
+func TestWebSocketClient_NonTLSConnection(t *testing.T) {
+	agent := createTestAgent(t)
+	upgrader := gws.NewUpgrader(&gws.BuiltinEventHandler{}, nil)
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		conn, err := upgrader.Upgrade(w, r)
+		if err == nil {
+			go conn.ReadLoop()
+		}
+	}))
+	t.Cleanup(server.Close)
+
+	t.Setenv("BESZEL_AGENT_HUB_URL", server.URL)
+	t.Setenv("BESZEL_AGENT_TOKEN", "test-token")
+	t.Setenv("BESZEL_AGENT_CA_CERT_FILE", "")
+	client, err := newWebSocketClient(agent)
+	require.NoError(t, err)
+	assert.Nil(t, client.getOptions().TlsConfig)
+
+	conn, _, err := gws.NewClient(&gws.BuiltinEventHandler{}, client.getOptions())
+	require.NoError(t, err)
+	require.NoError(t, conn.NetConn().Close())
+}
+
+func TestGetTLSConfigErrors(t *testing.T) {
+	tempDir := t.TempDir()
+	testCases := []struct {
+		name       string
+		path       string
+		contents   []byte
+		errorMatch string
+	}{
+		{
+			name:       "missing file",
+			path:       filepath.Join(tempDir, "missing.pem"),
+			errorMatch: "read CA_CERT_FILE",
+		},
+		{
+			name:       "unreadable path",
+			path:       tempDir,
+			errorMatch: "read CA_CERT_FILE",
+		},
+		{
+			name:       "empty file",
+			path:       filepath.Join(tempDir, "empty.pem"),
+			contents:   []byte{},
+			errorMatch: "does not contain any valid PEM certificates",
+		},
+		{
+			name:       "malformed file",
+			path:       filepath.Join(tempDir, "malformed.pem"),
+			contents:   []byte("not a PEM certificate"),
+			errorMatch: "does not contain any valid PEM certificates",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			if tc.contents != nil {
+				require.NoError(t, os.WriteFile(tc.path, tc.contents, 0600))
+			}
+			t.Setenv("BESZEL_AGENT_CA_CERT_FILE", tc.path)
+
+			tlsConfig, err := getTLSConfig()
+			require.Error(t, err)
+			assert.Nil(t, tlsConfig)
+			assert.Contains(t, err.Error(), tc.errorMatch)
+			assert.Contains(t, err.Error(), tc.path)
+		})
+	}
+}
+
+func newSelfSignedServerCertificate(t *testing.T) (tls.Certificate, []byte) {
+	t.Helper()
+	privateKey, err := rsa.GenerateKey(rand.Reader, 2048)
+	require.NoError(t, err)
+
+	template := &x509.Certificate{
+		SerialNumber:          big.NewInt(1),
+		Subject:               pkix.Name{CommonName: "127.0.0.1"},
+		NotBefore:             time.Now().Add(-time.Hour),
+		NotAfter:              time.Now().Add(time.Hour),
+		IPAddresses:           []net.IP{net.ParseIP("127.0.0.1")},
+		KeyUsage:              x509.KeyUsageDigitalSignature | x509.KeyUsageKeyEncipherment | x509.KeyUsageCertSign,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
+		BasicConstraintsValid: true,
+		IsCA:                  true,
+	}
+	certDER, err := x509.CreateCertificate(rand.Reader, template, template, &privateKey.PublicKey, privateKey)
+	require.NoError(t, err)
+
+	certPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: certDER})
+	keyPEM := pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(privateKey)})
+	certificate, err := tls.X509KeyPair(certPEM, keyPEM)
+	require.NoError(t, err)
+	return certificate, certPEM
+}
+
 // TestWebSocketClient_VerifySignature tests signature verification
 func TestWebSocketClient_VerifySignature(t *testing.T) {
 	agent := createTestAgent(t)
@@ -409,6 +592,41 @@ func TestGetToken(t *testing.T) {
 		assert.Equal(t, expectedToken, token)
 	})
 
+	t.Run("TOKEN_FILE with surrounding blank lines and comments", func(t *testing.T) {
+		expectedToken := "test-token-with-noise"
+		tokenFile := filepath.Join(t.TempDir(), "token")
+		require.NoError(t, os.WriteFile(tokenFile, []byte("# hub token\n\n"+expectedToken+"\n\n"), 0o600))
+
+		t.Setenv("TOKEN_FILE", tokenFile)
+
+		token, err := getToken()
+		assert.NoError(t, err)
+		assert.Equal(t, expectedToken, token)
+	})
+
+	t.Run("TOKEN_FILE with multiple tokens is rejected", func(t *testing.T) {
+		tokenFile := filepath.Join(t.TempDir(), "token")
+		require.NoError(t, os.WriteFile(tokenFile, []byte("11111111-1111-1111-1111-111111111111\n22222222-2222-2222-2222-222222222222\n"), 0o600))
+
+		t.Setenv("TOKEN_FILE", tokenFile)
+
+		token, err := getToken()
+		require.Error(t, err)
+		assert.Empty(t, token)
+		assert.Contains(t, err.Error(), "must contain a single token")
+	})
+
+	t.Run("TOKEN_FILE holding only comments behaves like an empty file", func(t *testing.T) {
+		tokenFile := filepath.Join(t.TempDir(), "token")
+		require.NoError(t, os.WriteFile(tokenFile, []byte("\n# only a comment\n"), 0o600))
+
+		t.Setenv("TOKEN_FILE", tokenFile)
+
+		token, err := getToken()
+		assert.NoError(t, err)
+		assert.Equal(t, "", token)
+	})
+
 	t.Run("token from BESZEL_AGENT_TOKEN_FILE", func(t *testing.T) {
 		// Create a temporary token file
 		expectedToken := "test-token-from-beszel-file"
@@ -504,3 +722,11 @@ func TestGetToken(t *testing.T) {
 		assert.Equal(t, expectedToken, token, "Whitespace should be stripped from token file content")
 	})
 }
+
+func TestWebSocketDeadlineCoversSlowCollection(t *testing.T) {
+	const minimumDeadline = 120 * time.Second
+
+	if wsDeadline < minimumDeadline {
+		t.Fatalf("WebSocket deadline %s is shorter than the slow-collection window of %s", wsDeadline, minimumDeadline)
+	}
+}

agent/connection_manager.go

@@ -87,7 +87,19 @@ func (c *ConnectionManager) Start(serverOptions ServerOptions) error {
 
 	wsClient, err := newWebSocketClient(c.agent)
 	if err != nil {
-		slog.Warn("Error creating WebSocket client", "err", err)
+		var caCertErr *caCertFileError
+		if errors.As(err, &caCertErr) {
+			return err
+		}
+		disableSSH, _ := utils.GetEnv("DISABLE_SSH")
+		if errors.Is(err, errNoHubURL) && disableSSH != "true" {
+			// SSH-only mode: the hub dials the agent, so there is nothing to warn
+			// about. With SSH also disabled there is no connection method at all,
+			// so that case still warns.
+			slog.Debug("WebSocket client not configured", "err", err)
+		} else {
+			slog.Warn("Error creating WebSocket client", "err", err)
+		}
 	}
 	c.wsClient = wsClient
 
@@ -151,7 +163,9 @@ func (c *ConnectionManager) handleEvent(event ConnectionEvent) {
 	case WebSocketConnect:
 		c.handleStateChange(WebSocketConnected)
 	case SSHConnect:
-		c.handleStateChange(SSHConnected)
+		if c.State == Disconnected {
+			c.handleStateChange(SSHConnected)
+		}
 	case WebSocketDisconnect:
 		if c.State == WebSocketConnected {
 			c.handleStateChange(Disconnected)

agent/connection_manager_test.go

@@ -114,6 +114,12 @@ func TestConnectionManager_EventHandling(t *testing.T) {
 			event:         SSHConnect,
 			expectedState: SSHConnected,
 		},
+		{
+			name:          "SSH connect from WebSocket connected (no change)",
+			initialState:  WebSocketConnected,
+			event:         SSHConnect,
+			expectedState: WebSocketConnected,
+		},
 		{
 			name:          "WebSocket disconnect from connected",
 			initialState:  WebSocketConnected,
@@ -265,6 +271,19 @@ func TestConnectionManager_StartWithInvalidConfig(t *testing.T) {
 	assert.Error(t, err, "Should error when starting already started connection manager")
 }
 
+func TestConnectionManager_StartRejectsInvalidCACertFile(t *testing.T) {
+	agent := createTestAgent(t)
+	cm := agent.connectionManager
+	t.Setenv("BESZEL_AGENT_HUB_URL", "https://hub.example.com")
+	t.Setenv("BESZEL_AGENT_TOKEN", "test-token")
+	t.Setenv("BESZEL_AGENT_CA_CERT_FILE", t.TempDir())
+
+	err := cm.Start(ServerOptions{})
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "read CA_CERT_FILE")
+	assert.Nil(t, cm.eventChan)
+}
+
 // TestConnectionManager_CloseWebSocket tests WebSocket closing
 func TestConnectionManager_CloseWebSocket(t *testing.T) {
 	agent := createTestAgent(t)

agent/data_dir_test.go

@@ -12,6 +12,14 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func invalidDataDir(t *testing.T) string {
+	t.Helper()
+
+	filePath := filepath.Join(t.TempDir(), "file")
+	require.NoError(t, os.WriteFile(filePath, nil, 0644))
+	return filepath.Join(filePath, "data")
+}
+
 func TestGetDataDir(t *testing.T) {
 	// Test with explicit dataDir parameter
 	t.Run("explicit data dir", func(t *testing.T) {
@@ -48,7 +56,7 @@ func TestGetDataDir(t *testing.T) {
 
 	// Test with invalid explicit dataDir
 	t.Run("invalid explicit data dir", func(t *testing.T) {
-		invalidPath := "/invalid/path/that/cannot/be/created"
+		invalidPath := invalidDataDir(t)
 		_, err := GetDataDir(invalidPath)
 		assert.Error(t, err)
 	})
@@ -78,7 +86,7 @@ func TestTestDataDirs(t *testing.T) {
 	// Test with multiple directories, first one valid
 	t.Run("multiple dirs - first valid", func(t *testing.T) {
 		tempDir := t.TempDir()
-		invalidDir := "/invalid/path"
+		invalidDir := invalidDataDir(t)
 		result, err := testDataDirs([]string{tempDir, invalidDir})
 		require.NoError(t, err)
 		assert.Equal(t, tempDir, result)
@@ -87,7 +95,7 @@ func TestTestDataDirs(t *testing.T) {
 	// Test with multiple directories, second one valid
 	t.Run("multiple dirs - second valid", func(t *testing.T) {
 		tempDir := t.TempDir()
-		invalidDir := "/invalid/path"
+		invalidDir := invalidDataDir(t)
 		result, err := testDataDirs([]string{invalidDir, tempDir})
 		require.NoError(t, err)
 		assert.Equal(t, tempDir, result)
@@ -109,7 +117,7 @@ func TestTestDataDirs(t *testing.T) {
 
 	// Test with no valid directories
 	t.Run("no valid directories", func(t *testing.T) {
-		invalidPaths := []string{"/invalid/path1", "/invalid/path2"}
+		invalidPaths := []string{invalidDataDir(t), invalidDataDir(t)}
 		_, err := testDataDirs(invalidPaths)
 		assert.Error(t, err)
 		assert.Contains(t, err.Error(), "data directory not found")

agent/disk.go

@@ -18,7 +18,8 @@ import (
 // fsRegistrationContext holds the shared lookup state needed to resolve a
 // filesystem into the tracked fsStats key and metadata.
 type fsRegistrationContext struct {
-	filesystem     string // value of optional FILESYSTEM env var
+	filesystem     string // device part of optional FILESYSTEM env var
+	filesystemName string // optional custom name from FILESYSTEM=device__name
 	isWindows      bool
 	efPath         string // path to extra filesystems (default "/extra-filesystems")
 	diskIoCounters map[string]disk.IOCountersStat
@@ -177,7 +178,7 @@ func (d *diskDiscovery) addConfiguredRootFs() bool {
 
 	for _, p := range d.partitions {
 		if filesystemMatchesPartitionSetting(d.ctx.filesystem, p) {
-			d.addFsStat(p.Device, p.Mountpoint, true, "")
+			d.addFsStat(p.Device, p.Mountpoint, true, d.ctx.filesystemName)
 			return true
 		}
 	}
@@ -185,7 +186,7 @@ func (d *diskDiscovery) addConfiguredRootFs() bool {
 	// FILESYSTEM may name a physical disk absent from partitions (e.g. ZFS lists
 	// dataset paths like zroot/ROOT/default, not block devices).
 	if ioKey, match := findIoDevice(d.ctx.filesystem, d.ctx.diskIoCounters); match {
-		d.agent.fsStats[ioKey] = &system.FsStats{Root: true, Mountpoint: d.rootMountPoint}
+		d.agent.fsStats[ioKey] = &system.FsStats{Root: true, Mountpoint: d.rootMountPoint, Name: d.ctx.filesystemName}
 		return true
 	}
 
@@ -300,7 +301,8 @@ func (d *diskDiscovery) addExtraFilesystemFolders(folderNames []string) {
 
 // Sets up the filesystems to monitor for disk usage and I/O.
 func (a *Agent) initializeDiskInfo() {
-	filesystem, _ := utils.GetEnv("FILESYSTEM")
+	filesystemRaw, _ := utils.GetEnv("FILESYSTEM")
+	filesystem, filesystemName := parseFilesystemEntry(filesystemRaw)
 	hasRoot := false
 	isWindows := runtime.GOOS == "windows"
 
@@ -324,6 +326,7 @@ func (a *Agent) initializeDiskInfo() {
 	slog.Debug("Disk I/O", "diskstats", diskIoCounters)
 	ctx := fsRegistrationContext{
 		filesystem:     filesystem,
+		filesystemName: filesystemName,
 		isWindows:      isWindows,
 		diskIoCounters: diskIoCounters,
 		efPath:         "/extra-filesystems",
@@ -534,7 +537,16 @@ func normalizeDeviceName(value string) string {
 func (a *Agent) initializeDiskIoStats(diskIoCounters map[string]disk.IOCountersStat) {
 	a.fsNames = a.fsNames[:0]
 	now := time.Now()
+	// ZFS datasets have no /proc/diskstats entry, so they are excluded from
+	// I/O tracking instead of warning about a missing device (#1541).
+	var zfsMountpoints map[string]bool
+	if a.storagePoolManager != nil {
+		zfsMountpoints = a.storagePoolManager.ZfsMountpoints()
+	}
 	for device, stats := range a.fsStats {
+		if zfsMountpoints[stats.Mountpoint] {
+			continue
+		}
 		// skip if not in diskIoCounters
 		d, exists := diskIoCounters[device]
 		if !exists {
@@ -559,20 +571,31 @@ func (a *Agent) updateDiskUsage(systemStats *system.Stats) {
 		!a.lastDiskUsageUpdate.IsZero() &&
 		time.Since(a.lastDiskUsageUpdate) < a.diskUsageCacheDuration
 
+	// ZFS dataset mountpoints use `zfs list` values because statfs(2) reports
+	// dataset-level usage that excludes child datasets (#1541).
+	var zfsUsage map[string]zfsDatasetUsage
+	if a.storagePoolManager != nil {
+		zfsUsage = a.storagePoolManager.DatasetUsage()
+	}
+
 	// disk usage
 	for _, stats := range a.fsStats {
 		// Skip non-root filesystems if caching is active
 		if cacheExtraFs && !stats.Root {
 			continue
 		}
-		if d, err := disk.Usage(stats.Mountpoint); err == nil {
+		var total, used uint64
-			stats.DiskTotal = utils.BytesToGigabytes(d.Total)
+		var usedPct float64
-			stats.DiskUsed = utils.BytesToGigabytes(d.Used)
+		if u, ok := zfsUsage[stats.Mountpoint]; ok {
-			if stats.Root {
+			total = u.used + u.avail
-				systemStats.DiskTotal = utils.BytesToGigabytes(d.Total)
+			used = u.used
-				systemStats.DiskUsed = utils.BytesToGigabytes(d.Used)
+			if total > 0 {
-				systemStats.DiskPct = utils.TwoDecimals(d.UsedPercent)
+				usedPct = float64(used) / float64(total) * 100
 			}
+		} else if d, err := disk.Usage(stats.Mountpoint); err == nil {
+			total = d.Total
+			used = d.Used
+			usedPct = d.UsedPercent
 		} else {
 			// reset stats if error (likely unmounted)
 			slog.Error("Error getting disk stats", "name", stats.Mountpoint, "err", err)
@@ -580,6 +603,14 @@ func (a *Agent) updateDiskUsage(systemStats *system.Stats) {
 			stats.DiskUsed = 0
 			stats.TotalRead = 0
 			stats.TotalWrite = 0
+			continue
+		}
+		stats.DiskTotal = utils.BytesToGigabytes(total)
+		stats.DiskUsed = utils.BytesToGigabytes(used)
+		if stats.Root {
+			systemStats.DiskTotal = stats.DiskTotal
+			systemStats.DiskUsed = stats.DiskUsed
+			systemStats.DiskPct = utils.TwoDecimals(usedPct)
 		}
 	}
 
@@ -696,6 +727,8 @@ func (a *Agent) updateDiskIo(cacheTimeMs uint16, systemStats *system.Stats) {
 				systemStats.DiskWritePs = stats.DiskWritePs
 				systemStats.DiskIO[0] = diskIORead
 				systemStats.DiskIO[1] = diskIOWrite
+				systemStats.DiskIOTotal[0] = d.ReadBytes
+				systemStats.DiskIOTotal[1] = d.WriteBytes
 				systemStats.DiskIoStats[0] = diskReadTime
 				systemStats.DiskIoStats[1] = diskWriteTime
 				systemStats.DiskIoStats[2] = diskIoUtilPct

agent/disk_test.go

@@ -78,14 +78,7 @@ func TestParseFilesystemEntry(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			fsEntry := strings.TrimSpace(tt.input)
+			fs, customName := parseFilesystemEntry(tt.input)
-			var fs, customName string
-			if parts := strings.SplitN(fsEntry, "__", 2); len(parts) == 2 {
-				fs = strings.TrimSpace(parts[0])
-				customName = strings.TrimSpace(parts[1])
-			} else {
-				fs = fsEntry
-			}
 
 			assert.Equal(t, tt.expectedFs, fs)
 			assert.Equal(t, tt.expectedName, customName)
@@ -287,8 +280,9 @@ func TestAddConfiguredRootFs(t *testing.T) {
 			rootMountPoint: "/",
 			partitions:     []disk.PartitionStat{{Device: "/dev/ada0p2", Mountpoint: "/"}},
 			ctx: fsRegistrationContext{
-				filesystem: "/dev/ada0p2",
+				filesystem:     "/dev/ada0p2",
-				isWindows:  false,
+				filesystemName: "root disk",
+				isWindows:      false,
 				diskIoCounters: map[string]disk.IOCountersStat{
 					"ada0": {Name: "ada0", ReadBytes: 1000, WriteBytes: 1000},
 				},
@@ -302,6 +296,7 @@ func TestAddConfiguredRootFs(t *testing.T) {
 		assert.True(t, exists)
 		assert.True(t, stats.Root)
 		assert.Equal(t, "/", stats.Mountpoint)
+		assert.Equal(t, "root disk", stats.Name)
 	})
 
 	t.Run("adds root from io device when partition is missing", func(t *testing.T) {
@@ -310,8 +305,9 @@ func TestAddConfiguredRootFs(t *testing.T) {
 			agent:          agent,
 			rootMountPoint: "/sysroot",
 			ctx: fsRegistrationContext{
-				filesystem: "zroot",
+				filesystem:     "zroot",
-				isWindows:  false,
+				filesystemName: "root pool",
+				isWindows:      false,
 				diskIoCounters: map[string]disk.IOCountersStat{
 					"nda0": {Name: "nda0", Label: "zroot", ReadBytes: 1000, WriteBytes: 1000},
 				},
@@ -325,6 +321,7 @@ func TestAddConfiguredRootFs(t *testing.T) {
 		assert.True(t, exists)
 		assert.True(t, stats.Root)
 		assert.Equal(t, "/sysroot", stats.Mountpoint)
+		assert.Equal(t, "root pool", stats.Name)
 	})
 
 	t.Run("returns false when filesystem cannot be resolved", func(t *testing.T) {

agent/disk_zfs_test.go

@@ -0,0 +1,110 @@
+//go:build testing
+
+package agent
+
+import (
+	"testing"
+	"time"
+
+	"github.com/henrygd/beszel/agent/zfs"
+	"github.com/henrygd/beszel/internal/entities/system"
+	"github.com/shirou/gopsutil/v4/disk"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestUpdateDiskUsageZfsMountpoint verifies that a filesystem whose mountpoint
+// is a ZFS dataset reports `zfs list` usage (which includes child datasets)
+// instead of the dataset-scoped statfs values (#1541).
+func TestUpdateDiskUsageZfsMountpoint(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) {
+		return []zfs.Dataset{
+			{Name: "tank", Used: 12000000000000, Avail: 11999000000000, Mountpoint: "/tank"},
+		}, nil
+	}
+	agent := &Agent{
+		fsStats: map[string]*system.FsStats{
+			"tank": {Root: false, Mountpoint: "/tank"},
+		},
+		storagePoolManager: zm,
+	}
+
+	var stats system.Stats
+	agent.updateDiskUsage(&stats)
+
+	fs := agent.fsStats["tank"]
+	require.NotNil(t, fs)
+	assert.Equal(t, 22350.81, fs.DiskTotal) // (used + avail) in GiB
+	assert.Equal(t, 11175.87, fs.DiskUsed)
+	// Non-root filesystems do not populate system-level stats.
+	assert.Equal(t, float64(0), stats.DiskTotal)
+}
+
+// TestUpdateDiskUsageZfsRootPopulatesSystemStats verifies the root disk values
+// are derived from ZFS usage when the root mountpoint is a ZFS dataset.
+func TestUpdateDiskUsageZfsRootPopulatesSystemStats(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) {
+		return []zfs.Dataset{
+			{Name: "rpool/ROOT/pve-1", Used: 900000000000, Avail: 300000000000, Mountpoint: "/"},
+		}, nil
+	}
+	agent := &Agent{
+		fsStats: map[string]*system.FsStats{
+			"rpool/ROOT/pve-1": {Root: true, Mountpoint: "/"},
+		},
+		storagePoolManager: zm,
+	}
+
+	var stats system.Stats
+	agent.updateDiskUsage(&stats)
+
+	assert.Equal(t, 1117.59, agent.fsStats["rpool/ROOT/pve-1"].DiskTotal)
+	assert.Equal(t, 838.19, agent.fsStats["rpool/ROOT/pve-1"].DiskUsed)
+	assert.Equal(t, 75.0, stats.DiskPct)
+	assert.Equal(t, 1117.59, stats.DiskTotal)
+	assert.Equal(t, 838.19, stats.DiskUsed)
+}
+
+// TestUpdateDiskUsageWithoutZfsManager falls back to statfs when no manager is
+// present (e.g. tests constructing bare Agent values).
+func TestUpdateDiskUsageWithoutZfsManager(t *testing.T) {
+	agent := &Agent{
+		fsStats: map[string]*system.FsStats{
+			"root": {Root: true, Mountpoint: "/"},
+		},
+	}
+
+	var stats system.Stats
+	agent.updateDiskUsage(&stats)
+
+	assert.True(t, agent.fsStats["root"].DiskTotal > 0, "root usage should come from statfs")
+	assert.True(t, stats.DiskTotal > 0)
+}
+
+// TestInitializeDiskIoStatsSkipsZfsMountpoints verifies ZFS filesystems are
+// excluded from diskstats I/O tracking instead of warning about a missing device.
+func TestInitializeDiskIoStatsSkipsZfsMountpoints(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) {
+		return []zfs.Dataset{{Name: "tank", Mountpoint: "/tank"}}, nil
+	}
+	agent := &Agent{
+		fsStats: map[string]*system.FsStats{
+			"tank": {Root: false, Mountpoint: "/tank"},
+			"sda1": {Root: false, Mountpoint: "/mnt/data"},
+		},
+		storagePoolManager: zm,
+		diskPrev:           make(map[uint16]map[string]prevDisk),
+	}
+
+	agent.initializeDiskIoStats(map[string]disk.IOCountersStat{
+		"sda1": {Name: "sda1", ReadBytes: 100, WriteBytes: 100},
+	})
+
+	assert.Equal(t, []string{"sda1"}, agent.fsNames)
+	assert.Equal(t, uint64(100), agent.fsStats["sda1"].TotalRead)
+	// ZFS entry is present but untouched by diskstats initialization.
+	assert.Equal(t, uint64(0), agent.fsStats["tank"].TotalRead)
+}

agent/docker.go

@@ -65,10 +65,14 @@ type dockerManager struct {
 	dockerVersionChecked bool                        // Whether a version probe has completed successfully
 	isWindows            bool                        // Whether the Docker Engine API is running on Windows
 	buf                  *bytes.Buffer               // Buffer to store and read response bodies
-	apiStats             *container.ApiStats         // Reusable API stats object
 	excludeContainers    []string                    // Patterns to exclude containers by name
 	usingPodman          bool                        // Whether the Docker Engine API is running on Podman
 
+	registryClient      *http.Client                  // Client for registry requests; nil uses a client with a 10-second timeout
+	imageUpdatesMutex   sync.RWMutex                  // Protects imageUpdates, its entries, and imageUpdatesRunning
+	imageUpdates        map[string]*imageUpdateStatus // Shared update status keyed by normalized image reference
+	imageUpdatesRunning bool                          // Whether a background image-update batch is in progress
+
 	// Cache-time-aware tracking for CPU stats (similar to cpu.go)
 	// Maps cache time intervals to container-specific CPU usage tracking
 	lastCpuContainer map[uint16]map[string]uint64    // cacheTimeMs -> containerId -> last cpu container usage
@@ -161,6 +165,9 @@ func (dm *dockerManager) getDockerStats(cacheTimeMs uint16) ([]*container.Stats,
 		clear(dm.validIds)
 	}
 
+	// Only schedule auxiliary work here; metrics never wait for image discovery.
+	dm.refreshImageUpdates(dm.apiContainerList, time.Now())
+
 	var failedContainers []*container.ApiInfo
 
 	for _, ctr := range dm.apiContainerList {
@@ -506,6 +513,17 @@ func (dm *dockerManager) updateContainerStats(ctr *container.ApiInfo, cacheTimeM
 		}
 	}
 
+	// Read and decode the response before locking shared stats to avoid blocking
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("container stats request failed: %s", resp.Status)
+	}
+	res := &container.ApiStats{}
+	if err := json.NewDecoder(resp.Body).Decode(res); err != nil {
+		return err
+	}
+	updateAvailable := dm.cachedImageUpdate(ctr.Image)
+
 	dm.containerStatsMutex.Lock()
 	defer dm.containerStatsMutex.Unlock()
 
@@ -520,6 +538,9 @@ func (dm *dockerManager) updateContainerStats(ctr *container.ApiInfo, cacheTimeM
 	stats.Status = statusText
 	stats.Health = health
 
+	stats.Image = ctr.Image
+	stats.UpdateAvailable = updateAvailable
+
 	if len(ctr.Ports) > 0 {
 		stats.Ports = convertContainerPortsToString(ctr)
 	}
@@ -532,12 +553,6 @@ func (dm *dockerManager) updateContainerStats(ctr *container.ApiInfo, cacheTimeM
 	stats.NetworkSent = 0
 	stats.NetworkRecv = 0
 
-	res := dm.apiStats
-	res.Networks = nil
-	if err := dm.decode(resp, res); err != nil {
-		return err
-	}
-
 	// Initialize CPU tracking for this cache time interval
 	dm.initializeCpuTracking(cacheTimeMs)
 
@@ -695,7 +710,6 @@ func newDockerManager(agent *Agent) *dockerManager {
 		containerStatsMap: make(map[string]*container.Stats),
 		sem:               make(chan struct{}, 5),
 		apiContainerList:  []*container.ApiInfo{},
-		apiStats:          &container.ApiStats{},
 		excludeContainers: excludeContainers,
 
 		// Initialize cache-time-aware tracking structures

agent/docker_image_updates.go

@@ -0,0 +1,105 @@
+package agent
+
+import (
+	"log/slog"
+	"sync"
+	"time"
+
+	"github.com/distribution/reference"
+	"github.com/henrygd/beszel/internal/entities/container"
+)
+
+const imageUpdateInterval = time.Hour
+
+type imageUpdateStatus struct {
+	available bool
+	checkedAt time.Time
+}
+
+func normalizedImageReference(image string) string {
+	named, err := reference.ParseNormalizedNamed(image)
+	if err != nil {
+		return ""
+	}
+	// Digest-pinned references cannot move to a new version.
+	if _, pinned := named.(reference.Digested); pinned {
+		return ""
+	}
+	return reference.TagNameOnly(named).String()
+}
+
+// refreshImageUpdates starts at most one background batch. Neither its network
+// work nor its completion is part of the container metrics wait group.
+func (dm *dockerManager) refreshImageUpdates(containers []*container.ApiInfo, now time.Time) {
+	dm.imageUpdatesMutex.Lock()
+	defer dm.imageUpdatesMutex.Unlock()
+	if dm.imageUpdatesRunning {
+		return
+	}
+	if dm.imageUpdates == nil {
+		dm.imageUpdates = make(map[string]*imageUpdateStatus)
+	}
+	active := make(map[string]struct{}, len(containers))
+	pending := make(map[string]*imageUpdateStatus)
+	for _, ctr := range containers {
+		if len(ctr.Names) > 0 && dm.shouldExcludeContainer(ctr.Names[0][1:]) {
+			continue
+		}
+		key := normalizedImageReference(ctr.Image)
+		if key == "" {
+			continue
+		}
+		active[key] = struct{}{}
+		entry := dm.imageUpdates[key]
+		if entry == nil {
+			entry = &imageUpdateStatus{}
+			dm.imageUpdates[key] = entry
+		}
+		if entry.checkedAt.IsZero() || now.Sub(entry.checkedAt) >= imageUpdateInterval {
+			pending[key] = entry
+		}
+	}
+	for key := range dm.imageUpdates {
+		if _, ok := active[key]; !ok {
+			delete(dm.imageUpdates, key)
+		}
+	}
+	if len(pending) == 0 {
+		return
+	}
+	dm.imageUpdatesRunning = true
+	go func() {
+		// Limit auxiliary requests even on hosts running many different images.
+		sem := make(chan struct{}, 2)
+		var wg sync.WaitGroup
+		for key, entry := range pending {
+			sem <- struct{}{}
+			wg.Add(1)
+			go func() {
+				defer wg.Done()
+				defer func() { <-sem }()
+				available, err := dm.checkImageUpdate(key)
+				if err != nil {
+					available = false
+					slog.Debug("Image update check failed", "image", key, "err", err)
+				}
+				dm.imageUpdatesMutex.Lock()
+				entry.available = available
+				entry.checkedAt = time.Now()
+				dm.imageUpdatesMutex.Unlock()
+			}()
+		}
+		wg.Wait()
+		dm.imageUpdatesMutex.Lock()
+		dm.imageUpdatesRunning = false
+		dm.imageUpdatesMutex.Unlock()
+	}()
+}
+
+func (dm *dockerManager) cachedImageUpdate(image string) bool {
+	key := normalizedImageReference(image)
+	dm.imageUpdatesMutex.RLock()
+	defer dm.imageUpdatesMutex.RUnlock()
+	entry := dm.imageUpdates[key]
+	return entry != nil && entry.available
+}

agent/docker_image_updates_test.go

@@ -0,0 +1,225 @@
+//go:build testing
+
+package agent
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/fxamacker/cbor/v2"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/henrygd/beszel/internal/entities/container"
+	"github.com/stretchr/testify/require"
+)
+
+func waitForImageUpdates(t *testing.T, dm *dockerManager) {
+	t.Helper()
+	require.Eventually(t, func() bool {
+		dm.imageUpdatesMutex.RLock()
+		defer dm.imageUpdatesMutex.RUnlock()
+		return !dm.imageUpdatesRunning
+	}, time.Second*3, time.Millisecond)
+}
+
+func TestImageUpdateCacheAndStats(t *testing.T) {
+	local := "sha256:" + strings.Repeat("a", 64)
+	remote := "sha256:" + strings.Repeat("b", 64)
+	var inspections, lookups atomic.Int32
+	var fail atomic.Bool
+	var upToDate atomic.Bool
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch {
+		case strings.HasPrefix(r.URL.Path, "/images/"):
+			inspections.Add(1)
+			fmt.Fprintf(w, `{"RepoDigests":["docker.io/library/nginx@%s"]}`, local)
+		case r.URL.Path == "/containers/json":
+			fmt.Fprint(w, `[{"Id":"aaaaaaaaaaaa","Names":["/one"],"Image":"nginx","Status":"Up 2 hours"},{"Id":"bbbbbbbbbbbb","Names":["/two"],"Image":"docker.io/library/nginx:latest","Status":"Up 2 hours"}]`)
+		case strings.Contains(r.URL.Path, "/stats"):
+			fmt.Fprint(w, `{"memory_stats":{"usage":1048576},"cpu_stats":{},"networks":{}}`)
+		default:
+			http.NotFound(w, r)
+		}
+	}))
+	defer server.Close()
+	dm := newDockerManagerForVersionTest(server)
+	dm.dockerVersionChecked = true
+	dm.registryClient = &http.Client{Timeout: time.Second, Transport: roundTripFunc(func(r *http.Request) (*http.Response, error) {
+		if fail.Load() {
+			return nil, fmt.Errorf("registry unavailable")
+		}
+		response := &http.Response{StatusCode: 200, Header: make(http.Header), Body: io.NopCloser(strings.NewReader(`{"token":"test"}`))}
+		if r.Method == http.MethodHead {
+			lookups.Add(1)
+			digest := remote
+			if upToDate.Load() {
+				digest = local
+			}
+			response.Header.Set("Docker-Content-Digest", digest)
+		}
+		return response, nil
+	})}
+	stats, err := dm.getDockerStats(defaultCacheTimeMs)
+	require.NoError(t, err)
+	require.Len(t, stats, 2)
+	waitForImageUpdates(t, dm)
+	require.EqualValues(t, 1, lookups.Load())
+	require.EqualValues(t, 1, inspections.Load())
+	stats, err = dm.getDockerStats(defaultCacheTimeMs)
+	require.NoError(t, err)
+	for _, stat := range stats {
+		require.True(t, stat.UpdateAvailable)
+		if stat.Id == "aaaaaaaaaaaa" {
+			require.Equal(t, "nginx", stat.Image)
+		} else {
+			require.Equal(t, "docker.io/library/nginx:latest", stat.Image)
+		}
+	}
+	require.EqualValues(t, 1, lookups.Load())
+
+	expire := func() {
+		dm.imageUpdatesMutex.Lock()
+		dm.imageUpdates["docker.io/library/nginx:latest"].checkedAt = time.Now().Add(-imageUpdateInterval)
+		dm.imageUpdatesMutex.Unlock()
+	}
+	upToDate.Store(true)
+	expire()
+	_, err = dm.getDockerStats(defaultCacheTimeMs)
+	require.NoError(t, err)
+	waitForImageUpdates(t, dm)
+	require.EqualValues(t, 2, lookups.Load())
+	require.False(t, dm.cachedImageUpdate("nginx:latest"))
+
+	// An expired positive result is cleared on failure, and the failure itself
+	// is cached so realtime stats do not retry a broken registry every second.
+	dm.imageUpdatesMutex.Lock()
+	dm.imageUpdates["docker.io/library/nginx:latest"].available = true
+	dm.imageUpdatesMutex.Unlock()
+	fail.Store(true)
+	expire()
+	_, err = dm.getDockerStats(defaultCacheTimeMs)
+	require.NoError(t, err)
+	waitForImageUpdates(t, dm)
+	failedInspections := inspections.Load()
+	stats, err = dm.getDockerStats(defaultCacheTimeMs)
+	require.NoError(t, err)
+	require.Len(t, stats, 2)
+	require.Equal(t, failedInspections, inspections.Load())
+	for _, stat := range stats {
+		require.False(t, stat.UpdateAvailable)
+		require.Equal(t, 1.0, stat.Mem)
+	}
+}
+
+func TestImageDiscoveryDoesNotBlockStats(t *testing.T) {
+	started := make(chan struct{}, 1)
+	release := make(chan struct{})
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if strings.HasPrefix(r.URL.Path, "/images/") {
+			fmt.Fprintf(w, `{"RepoDigests":["example.com/app@sha256:%s"]}`, strings.Repeat("a", 64))
+		} else {
+			fmt.Fprint(w, `{"memory_stats":{"usage":1048576}}`)
+		}
+	}))
+	defer server.Close()
+	dm := newDockerManagerForVersionTest(server)
+	defer func() { close(release); waitForImageUpdates(t, dm) }()
+	dm.registryClient = &http.Client{Transport: roundTripFunc(func(r *http.Request) (*http.Response, error) {
+		started <- struct{}{}
+		<-release
+		return nil, fmt.Errorf("timeout")
+	})}
+	ctr := &container.ApiInfo{IdShort: "aaaaaaaaaaaa", Image: "example.com/app", Names: []string{"/one"}}
+	dm.refreshImageUpdates([]*container.ApiInfo{ctr}, time.Now())
+	select {
+	case <-started:
+	case <-time.After(3 * time.Second):
+		t.Fatal("check did not start")
+	}
+	done := make(chan error, 1)
+	go func() { done <- dm.updateContainerStats(ctr, defaultCacheTimeMs) }()
+	select {
+	case err := <-done:
+		require.NoError(t, err)
+	case <-time.After(time.Second):
+		t.Fatal("registry blocked stats")
+	}
+	dm.imageUpdatesMutex.RLock()
+	require.True(t, dm.imageUpdatesRunning)
+	dm.imageUpdatesMutex.RUnlock()
+}
+
+func TestNormalizeImageUpdateReferences(t *testing.T) {
+	require.Equal(t, normalizedImageReference("nginx"), normalizedImageReference("docker.io/library/nginx:latest"))
+	require.Empty(t, normalizedImageReference("bad reference"))
+	require.Empty(t, normalizedImageReference("nginx@sha256:"+strings.Repeat("a", 64)))
+}
+
+// A stats request can return headers promptly and then stall while reading its
+// body. The stats-map mutex must remain available during that read.
+func TestStatsResponseBodyDoesNotHoldStatsLock(t *testing.T) {
+	started := make(chan struct{})
+	release := make(chan struct{})
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		w.(http.Flusher).Flush()
+		close(started)
+		<-release
+		fmt.Fprint(w, `{"memory_stats":{"usage":1048576}}`)
+	}))
+	defer server.Close()
+	dm := newDockerManagerForVersionTest(server)
+	done := make(chan error, 1)
+	go func() {
+		done <- dm.updateContainerStats(&container.ApiInfo{IdShort: "aaaaaaaaaaaa", Names: []string{"/one"}, Image: "nginx"}, defaultCacheTimeMs)
+	}()
+	<-started
+	locked := make(chan struct{})
+	go func() { dm.containerStatsMutex.Lock(); dm.containerStatsMutex.Unlock(); close(locked) }()
+	select {
+	case <-locked:
+	case <-time.After(time.Second):
+		close(release)
+		<-done
+		t.Fatal("Docker response body held the stats mutex")
+	}
+	close(release)
+	require.NoError(t, <-done)
+}
+
+func TestImageUpdateStatsEncoding(t *testing.T) {
+	original := container.Stats{Image: "nginx:latest", UpdateAvailable: true}
+	encoded, err := cbor.Marshal(original)
+	require.NoError(t, err)
+	var fields map[int]any
+	require.NoError(t, cbor.Unmarshal(encoded, &fields))
+	require.Equal(t, true, fields[11])
+	require.Equal(t, "nginx:latest", fields[8])
+	var decoded container.Stats
+	require.NoError(t, cbor.Unmarshal(encoded, &decoded))
+	require.True(t, decoded.UpdateAvailable)
+	require.Equal(t, original.Image, decoded.Image)
+	encoded, err = json.Marshal(original)
+	require.NoError(t, err)
+	require.Contains(t, string(encoded), `"u":true`)
+}
+
+func TestImageUpdateCacheExpiryBoundaryAndPruning(t *testing.T) {
+	now := time.Now()
+	key := normalizedImageReference("nginx")
+	dm := &dockerManager{imageUpdates: map[string]*imageUpdateStatus{
+		key:                           {available: true, checkedAt: now},
+		"unused.example/image:latest": {checkedAt: now},
+	}}
+	dm.refreshImageUpdates([]*container.ApiInfo{{Image: "nginx"}}, now.Add(imageUpdateInterval-time.Nanosecond))
+	require.False(t, dm.imageUpdatesRunning)
+	require.Len(t, dm.imageUpdates, 1)
+	require.True(t, dm.cachedImageUpdate("nginx:latest"))
+	dm.refreshImageUpdates(nil, now)
+	require.Empty(t, dm.imageUpdates)
+}

agent/docker_registry.go

@@ -0,0 +1,222 @@
+package agent
+
+import (
+	_ "crypto/sha256"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"github.com/distribution/reference"
+	"github.com/opencontainers/go-digest"
+)
+
+const imageRegistryTimeout = 10 * time.Second
+
+const imageManifestAccept = "application/vnd.docker.distribution.manifest.list.v2+json, " +
+	"application/vnd.docker.distribution.manifest.v2+json, " +
+	"application/vnd.oci.image.manifest.v1+json, " +
+	"application/vnd.oci.image.index.v1+json"
+
+// checkImageUpdate compares the digest recorded by Docker for image with the
+// digest currently advertised by its registry. A digest-pinned reference is
+// immutable and therefore never has an update available.
+func (dm *dockerManager) checkImageUpdate(image string) (bool, error) {
+	named, err := reference.ParseNormalizedNamed(image)
+	if err != nil {
+		return false, fmt.Errorf("parse image reference %q: %w", image, err)
+	}
+	if _, pinned := named.(reference.Digested); pinned {
+		return false, nil
+	}
+	named = reference.TagNameOnly(named)
+
+	registry := reference.Domain(named)
+	repository := reference.Path(named)
+	tag := named.(reference.Tagged).Tag()
+
+	localDigest, err := dm.inspectImageDigest(image, registry, repository)
+	if err != nil {
+		return false, err
+	}
+
+	remoteDigest, err := dm.registryImageDigest(registry, repository, tag)
+	if err != nil {
+		return false, err
+	}
+
+	return remoteDigest != localDigest, nil
+}
+
+// inspectImageDigest reads Docker's image metadata without using dm.decode.
+// The checker runs in the image-discovery goroutine, so it must not hold any
+// of the container statistics locks while waiting on the Docker API.
+func (dm *dockerManager) inspectImageDigest(image, registry, repository string) (string, error) {
+	if dm.client == nil {
+		return "", fmt.Errorf("inspect image %q: Docker client is unavailable", image)
+	}
+
+	endpoint := "http://localhost/images/" + url.PathEscape(image) + "/json"
+	resp, err := dm.client.Get(endpoint)
+	if err != nil {
+		return "", fmt.Errorf("inspect image %q: %w", image, err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("inspect image %q failed: %s", image, responseStatus(resp))
+	}
+
+	var inspect struct {
+		RepoDigests []string `json:"RepoDigests"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&inspect); err != nil {
+		return "", fmt.Errorf("decode image inspect %q: %w", image, err)
+	}
+	if len(inspect.RepoDigests) == 0 {
+		return "", fmt.Errorf("inspect image %q returned no repository digests", image)
+	}
+
+	localDigest, ok := matchingRepositoryDigest(inspect.RepoDigests, registry, repository)
+	if !ok {
+		return "", fmt.Errorf("inspect image %q returned no valid digest for %s/%s", image, registry, repository)
+	}
+	return localDigest, nil
+}
+
+// matchingRepositoryDigest returns a valid digest belonging to the requested
+// repository. Docker can return multiple RepoDigests for one local image; an
+// unrelated first entry must never be used for the comparison.
+func matchingRepositoryDigest(repoDigests []string, registry, repository string) (string, bool) {
+	for _, repoDigest := range repoDigests {
+		repoDigest = strings.TrimSpace(repoDigest)
+		at := strings.LastIndexByte(repoDigest, '@')
+		if at <= 0 || at == len(repoDigest)-1 || strings.Contains(repoDigest[:at], "@") {
+			continue
+		}
+
+		repoRef, err := reference.ParseNormalizedNamed(repoDigest[:at])
+		if err != nil || reference.Path(repoRef) != repository || !sameRegistry(reference.Domain(repoRef), registry) {
+			continue
+		}
+		if _, hasTag := repoRef.(reference.Tagged); hasTag {
+			continue
+		}
+
+		d, err := digest.Parse(repoDigest[at+1:])
+		if err != nil {
+			continue
+		}
+		return d.String(), true
+	}
+	return "", false
+}
+
+func sameRegistry(left, right string) bool {
+	left = canonicalRegistry(left)
+	right = canonicalRegistry(right)
+	return left == right ||
+		(left == "ghcr.io" && right == "lscr.io") ||
+		(left == "lscr.io" && right == "ghcr.io")
+}
+
+func canonicalRegistry(registry string) string {
+	if registry == "index.docker.io" {
+		return "docker.io"
+	}
+	return registry
+}
+
+func (dm *dockerManager) registryImageDigest(registry, repository, tag string) (string, error) {
+	client := dm.registryClient
+	if client == nil {
+		client = &http.Client{Timeout: imageRegistryTimeout}
+	}
+
+	token, err := dm.registryToken(client, registry, repository)
+	if err != nil {
+		return "", err
+	}
+
+	host := registry
+	if registry == "docker.io" {
+		host = "registry-1.docker.io"
+	}
+	manifestURL := "https://" + host + "/v2/" + repository + "/manifests/" + url.PathEscape(tag)
+	req, err := http.NewRequest(http.MethodHead, manifestURL, nil)
+	if err != nil {
+		return "", fmt.Errorf("create manifest request: %w", err)
+	}
+	req.Header.Set("Accept", imageManifestAccept)
+	if token != "" {
+		req.Header.Set("Authorization", "Bearer "+token)
+	}
+
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("fetch manifest %s:%s: %w", registry, repository, err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("manifest request for %s:%s failed: %s", repository, tag, responseStatus(resp))
+	}
+
+	remote := strings.TrimSpace(resp.Header.Get("Docker-Content-Digest"))
+	d, err := digest.Parse(remote)
+	if err != nil {
+		return "", fmt.Errorf("manifest request for %s:%s returned invalid digest: %w", repository, tag, err)
+	}
+	return d.String(), nil
+}
+
+func (dm *dockerManager) registryToken(client *http.Client, registry, repository string) (string, error) {
+	var authURL string
+	switch registry {
+	case "docker.io":
+		authURL = "https://auth.docker.io/token?service=registry.docker.io&scope=" + url.QueryEscape("repository:"+repository+":pull")
+	case "ghcr.io", "lscr.io":
+		// lscr.io is the LinuxServer alias for its GHCR-backed images.
+		authURL = "https://ghcr.io/token?service=ghcr.io&scope=" + url.QueryEscape("repository:"+repository+":pull")
+	default:
+		// Anonymous registries remain supported, as they were before the
+		// authenticated Docker Hub and GHCR paths were added.
+		return "", nil
+	}
+
+	req, err := http.NewRequest(http.MethodGet, authURL, nil)
+	if err != nil {
+		return "", fmt.Errorf("create registry auth request: %w", err)
+	}
+	resp, err := client.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("fetch registry auth token for %s: %w", repository, err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return "", fmt.Errorf("registry auth request for %s failed: %s", repository, responseStatus(resp))
+	}
+
+	var tokenResponse struct {
+		Token       string `json:"token"`
+		AccessToken string `json:"access_token"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&tokenResponse); err != nil {
+		return "", fmt.Errorf("decode registry auth response for %s: %w", repository, err)
+	}
+	token := strings.TrimSpace(tokenResponse.Token)
+	if token == "" {
+		token = strings.TrimSpace(tokenResponse.AccessToken)
+	}
+	if token == "" {
+		return "", fmt.Errorf("registry auth response for %s contained no token", repository)
+	}
+	return token, nil
+}
+
+func responseStatus(resp *http.Response) string {
+	if resp.Status != "" {
+		return resp.Status
+	}
+	return http.StatusText(resp.StatusCode)
+}

agent/docker_registry_test.go

@@ -0,0 +1,204 @@
+//go:build testing
+
+package agent
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync/atomic"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+type registryTransportFunc func(*http.Request) (*http.Response, error)
+
+func (fn registryTransportFunc) RoundTrip(req *http.Request) (*http.Response, error) {
+	return fn(req)
+}
+
+func registryResponse(status int, body string) *http.Response {
+	return &http.Response{
+		StatusCode: status,
+		Status:     fmt.Sprintf("%d %s", status, http.StatusText(status)),
+		Header:     make(http.Header),
+		Body:       io.NopCloser(strings.NewReader(body)),
+	}
+}
+
+func registryDigest(fill byte) string {
+	return "sha256:" + strings.Repeat(string(fill), 64)
+}
+
+func newRegistryChecker(t *testing.T, inspectBody string, transport http.RoundTripper) *dockerManager {
+	t.Helper()
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if strings.HasPrefix(r.URL.Path, "/images/") {
+			w.Header().Set("Content-Type", "application/json")
+			_, _ = io.WriteString(w, inspectBody)
+			return
+		}
+		http.NotFound(w, r)
+	}))
+	t.Cleanup(server.Close)
+
+	return &dockerManager{
+		client:         newDockerManagerForVersionTest(server).client,
+		registryClient: &http.Client{Transport: transport},
+	}
+}
+
+func TestCheckImageUpdateUsesInspectAndManifestDigests(t *testing.T) {
+	local := registryDigest('a')
+	remote := registryDigest('b')
+	var authCalls, manifestCalls atomic.Int32
+	dm := newRegistryChecker(t, fmt.Sprintf(`{"RepoDigests":["docker.io/library/alpine@%s"]}`, local), registryTransportFunc(func(req *http.Request) (*http.Response, error) {
+		switch {
+		case req.Method == http.MethodGet && req.URL.Host == "auth.docker.io":
+			authCalls.Add(1)
+			require.Equal(t, "/token", req.URL.Path)
+			return registryResponse(http.StatusOK, `{"token":"test-token"}`), nil
+		case req.Method == http.MethodHead && req.URL.Host == "registry-1.docker.io":
+			manifestCalls.Add(1)
+			require.Equal(t, "/v2/library/alpine/manifests/latest", req.URL.Path)
+			require.Equal(t, "Bearer test-token", req.Header.Get("Authorization"))
+			resp := registryResponse(http.StatusOK, "")
+			resp.Header.Set("Docker-Content-Digest", remote)
+			return resp, nil
+		default:
+			return registryResponse(http.StatusNotFound, ""), nil
+		}
+	}))
+
+	available, err := dm.checkImageUpdate("alpine")
+	require.NoError(t, err)
+	require.True(t, available)
+	require.EqualValues(t, 1, authCalls.Load())
+	require.EqualValues(t, 1, manifestCalls.Load())
+}
+
+func TestCheckImageUpdateReportsUnknownInspectState(t *testing.T) {
+	for _, test := range []struct {
+		name string
+		body string
+	}{
+		{name: "missing field", body: `{}`},
+		{name: "empty field", body: `{"RepoDigests":[]}`},
+		{name: "malformed reference", body: `{"RepoDigests":["not-a-repo-digest"]}`},
+		{name: "wrong repository", body: `{"RepoDigests":["docker.io/library/busybox@` + registryDigest('a') + `"]}`},
+		{name: "malformed digest", body: `{"RepoDigests":["docker.io/library/alpine@sha256:not-a-digest"]}`},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			var registryCalls atomic.Int32
+			dm := newRegistryChecker(t, test.body, registryTransportFunc(func(req *http.Request) (*http.Response, error) {
+				registryCalls.Add(1)
+				return registryResponse(http.StatusOK, `{"token":"unexpected"}`), nil
+			}))
+
+			available, err := dm.checkImageUpdate("alpine")
+			require.Error(t, err)
+			require.False(t, available)
+			require.EqualValues(t, 0, registryCalls.Load(), "invalid local state must not query a registry")
+		})
+	}
+}
+
+func TestCheckImageUpdateChecksInspectAuthAndManifestStatuses(t *testing.T) {
+	local := registryDigest('a')
+	validInspect := fmt.Sprintf(`{"RepoDigests":["docker.io/library/alpine@%s"]}`, local)
+
+	tests := []struct {
+		name         string
+		inspectCode  int
+		authCode     int
+		manifestCode int
+		remote       string
+		want         string
+	}{
+		{name: "inspect status", inspectCode: http.StatusNotFound, want: "inspect image"},
+		{name: "auth status", inspectCode: http.StatusOK, authCode: http.StatusUnauthorized, want: "registry auth"},
+		{name: "manifest status", inspectCode: http.StatusOK, authCode: http.StatusOK, manifestCode: http.StatusNotFound, remote: local, want: "manifest request"},
+		{name: "missing digest", inspectCode: http.StatusOK, authCode: http.StatusOK, manifestCode: http.StatusOK, want: "invalid digest"},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				if test.inspectCode != http.StatusOK && strings.HasPrefix(r.URL.Path, "/images/") {
+					w.WriteHeader(test.inspectCode)
+					return
+				}
+				_, _ = io.WriteString(w, validInspect)
+			}))
+			t.Cleanup(server.Close)
+
+			calls := 0
+			dm := &dockerManager{client: newDockerManagerForVersionTest(server).client, registryClient: &http.Client{Transport: registryTransportFunc(func(req *http.Request) (*http.Response, error) {
+				calls++
+				if req.Method == http.MethodGet {
+					return registryResponse(test.authCode, `{"token":"test"}`), nil
+				}
+				response := registryResponse(test.manifestCode, "")
+				response.Header.Set("Docker-Content-Digest", test.remote)
+				return response, nil
+			})}}
+
+			_, err := dm.checkImageUpdate("alpine")
+			require.Error(t, err)
+			require.Contains(t, err.Error(), test.want)
+			if test.inspectCode != http.StatusOK {
+				require.Zero(t, calls)
+			}
+		})
+	}
+}
+
+func TestCheckImageUpdateSupportsAnonymousAndLSCRRegistries(t *testing.T) {
+	t.Run("anonymous registry", func(t *testing.T) {
+		local := registryDigest('a')
+		var calls atomic.Int32
+		dm := newRegistryChecker(t, fmt.Sprintf(`{"RepoDigests":["example.com/app@%s"]}`, local), registryTransportFunc(func(req *http.Request) (*http.Response, error) {
+			calls.Add(1)
+			require.Equal(t, http.MethodHead, req.Method)
+			require.Equal(t, "example.com", req.URL.Host)
+			resp := registryResponse(http.StatusOK, "")
+			resp.Header.Set("Docker-Content-Digest", local)
+			return resp, nil
+		}))
+		available, err := dm.checkImageUpdate("example.com/app")
+		require.NoError(t, err)
+		require.False(t, available)
+		require.EqualValues(t, 1, calls.Load())
+	})
+
+	t.Run("lscr ghcr alias", func(t *testing.T) {
+		local := registryDigest('a')
+		var authCalls, manifestCalls atomic.Int32
+		dm := newRegistryChecker(t, fmt.Sprintf(`{"RepoDigests":["ghcr.io/linuxserver/app@%s"]}`, local), registryTransportFunc(func(req *http.Request) (*http.Response, error) {
+			if req.Method == http.MethodGet {
+				authCalls.Add(1)
+				return registryResponse(http.StatusOK, `{"token":"test"}`), nil
+			}
+			manifestCalls.Add(1)
+			require.Equal(t, "lscr.io", req.URL.Host)
+			resp := registryResponse(http.StatusOK, "")
+			resp.Header.Set("Docker-Content-Digest", local)
+			return resp, nil
+		}))
+		available, err := dm.checkImageUpdate("lscr.io/linuxserver/app")
+		require.NoError(t, err)
+		require.False(t, available)
+		require.EqualValues(t, 1, authCalls.Load())
+		require.EqualValues(t, 1, manifestCalls.Load())
+	})
+}
+
+func TestCheckImageUpdateSkipsPinnedDigest(t *testing.T) {
+	image := "docker.io/library/alpine@" + registryDigest('a')
+	dm := &dockerManager{}
+	available, err := dm.checkImageUpdate(image)
+	require.NoError(t, err)
+	require.False(t, available)
+}

agent/docker_test.go

@@ -729,6 +729,7 @@ func TestGetDockerStatsChecksDockerVersionAfterContainerList(t *testing.T) {
 
 			stats, err := dm.getDockerStats(defaultCacheTimeMs)
 			require.NoError(t, err)
+			require.NotNil(t, stats, "A successful empty snapshot must remain distinguishable from a collection failure")
 			assert.Empty(t, stats)
 			assert.True(t, dm.dockerVersionChecked)
 			assert.Equal(t, tt.expectedGood, dm.goodDockerVersion)
@@ -742,6 +743,7 @@ func TestGetDockerStatsChecksDockerVersionAfterContainerList(t *testing.T) {
 
 			stats, err = dm.getDockerStats(defaultCacheTimeMs)
 			require.NoError(t, err)
+			require.NotNil(t, stats, "A successful empty snapshot must remain distinguishable from a collection failure")
 			assert.Empty(t, stats)
 			assert.Equal(t, tt.expectedGood, dm.goodDockerVersion)
 			assert.Equal(t, tt.expectedPodman, dm.usingPodman)
@@ -1182,7 +1184,6 @@ func TestUpdateContainerStatsPodmanCpuCalculation(t *testing.T) {
 			}
 		})},
 		containerStatsMap: make(map[string]*container.Stats),
-		apiStats:          &container.ApiStats{},
 		usingPodman:       true,
 		lastCpuContainer: map[uint16]map[string]uint64{
 			defaultCacheTimeMs: {"0123456789ab": prevCpuUsage},
@@ -1674,7 +1675,6 @@ func TestUpdateContainerStatsUsesPodmanInspectHealthFallback(t *testing.T) {
 			}
 		})},
 		containerStatsMap:   make(map[string]*container.Stats),
-		apiStats:            &container.ApiStats{},
 		usingPodman:         true,
 		lastCpuContainer:    make(map[uint16]map[string]uint64),
 		lastCpuSystem:       make(map[uint16]map[string]uint64),

agent/fans.go

@@ -72,14 +72,30 @@ func discoverHwmonFans(root string) ([]fanSensor, error) {
 	var sensors []fanSensor
 	for _, entry := range entries {
 		chipDir := filepath.Join(root, entry.Name())
-		chipName := utils.ReadStringFile(filepath.Join(chipDir, "name"))
+		sensorDir := chipDir
+		inputs, _ := filepath.Glob(filepath.Join(sensorDir, "fan*_input"))
+
+		// Some legacy hwmon drivers (notably applesmc) register a hwmon class
+		// device but create fan attributes on the parent platform device. In
+		// sysfs that parent is exposed through hwmonN/device.
+		if len(inputs) == 0 {
+			deviceDir := filepath.Join(chipDir, "device")
+			if deviceInputs, _ := filepath.Glob(filepath.Join(deviceDir, "fan*_input")); len(deviceInputs) > 0 {
+				sensorDir = deviceDir
+				inputs = deviceInputs
+			}
+		}
+
+		chipName := utils.ReadStringFile(filepath.Join(sensorDir, "name"))
+		if chipName == "" {
+			chipName = utils.ReadStringFile(filepath.Join(chipDir, "name"))
+		}
 		if chipName == "" {
 			chipName = entry.Name()
 		}
-		inputs, _ := filepath.Glob(filepath.Join(chipDir, "fan*_input"))
 		for _, inputPath := range inputs {
 			base := strings.TrimSuffix(filepath.Base(inputPath), "_input")
-			label := utils.ReadStringFile(filepath.Join(chipDir, base+"_label"))
+			label := utils.ReadStringFile(filepath.Join(sensorDir, base+"_label"))
 			key := chipName + "_" + base
 			if label != "" {
 				key = chipName + "_" + label

agent/fans_test.go

@@ -50,6 +50,24 @@ func TestReadHwmonFans(t *testing.T) {
 	}, fans)
 }
 
+// TestReadHwmonFansLegacyParent verifies legacy hwmon layouts such as applesmc,
+// where the hwmon class node exists but fan attributes live on hwmonN/device.
+func TestReadHwmonFansLegacyParent(t *testing.T) {
+	root := t.TempDir()
+	deviceDir := filepath.Join(root, "devices", "applesmc.768")
+	writeFile(t, filepath.Join(deviceDir, "name"), "applesmc\n")
+	writeFile(t, filepath.Join(deviceDir, "fan1_input"), "1202\n")
+	writeFile(t, filepath.Join(deviceDir, "fan1_label"), "Exhaust\n")
+
+	chipDir := filepath.Join(root, "hwmon1")
+	require.NoError(t, os.MkdirAll(chipDir, 0o755))
+	require.NoError(t, os.Symlink(deviceDir, filepath.Join(chipDir, "device")))
+
+	fans, err := readHwmonFans(root)
+	require.NoError(t, err)
+	assert.Equal(t, map[string]uint16{"applesmc_Exhaust": 1202}, fans)
+}
+
 // TestReadHwmonFansMissingRoot returns an error rather than panicking when the
 // hwmon root doesn't exist (e.g. running on a kernel without hwmon support).
 func TestReadHwmonFansMissingRoot(t *testing.T) {

agent/fingerprint.go

@@ -50,6 +50,9 @@ func generateFingerprint(hostname, cpuModel string) string {
 			if info, err := cpu.Info(); err == nil && len(info) > 0 {
 				cpuModel = info[0].ModelName
 			}
+			if cpuModel == "" {
+				cpuModel = getCpuModelFromCpuinfo()
+			}
 		}
 		fingerprint = hostname + cpuModel
 	}

agent/gpu.go

@@ -361,12 +361,16 @@ func (gm *GPUManager) calculateGPUAverage(id string, gpu *system.GPUData, cacheK
 
 	// If no new data arrived
 	if deltaCount == 0 {
-		// If GPU appears suspended (instantaneous values are 0), return zero values
+		// Only discrete GPUs report temp/memory, so treat all-zero as suspended (return zeros).
-		// Otherwise return last known average for temporary collection gaps
+		// Engine-based (Intel) GPUs don't, so carry the last average forward across sample gaps.
-		if gpu.Temperature == 0 && gpu.MemoryUsed == 0 {
+		if gpu.Engines == nil && gpu.Temperature == 0 && gpu.MemoryUsed == 0 {
 			return system.GPUData{Name: gpu.Name}
 		}
-		return gm.lastAvgData[id] // zero value if not found
+		lastAvg := gm.lastAvgData[id] // zero value if not found
+		if lastAvg.Name == "" {
+			lastAvg.Name = gpu.Name
+		}
+		return lastAvg
 	}
 
 	// Calculate new average

agent/gpu_test.go

@@ -566,6 +566,42 @@ func TestGetCurrentData(t *testing.T) {
 		assert.EqualValues(t, 2, gm.GpuDataMap["0"].Count, "Count should still be 2")
 	})
 
+	t.Run("carries Intel GPU average forward between samples", func(t *testing.T) {
+		// Intel GPUs report no temp/memory, so between-sample gaps (delta 0) must
+		// reuse the last average instead of returning zeros and blanking the chart.
+		gm := &GPUManager{
+			GpuDataMap: map[string]*system.GPUData{
+				"0": {
+					Name:     "GPU",
+					Usage:    0,   // derived from engines for Intel
+					Power:    200, // averages to 100 over 2 counts
+					PowerPkg: 60,  // averages to 30 over 2 counts
+					Count:    2,
+					Engines: map[string]float64{
+						"Render/3D": 80, // averages to 40
+						"Video":     20, // averages to 10
+					},
+				},
+			},
+		}
+
+		cacheKey := uint16(1000) // realtime cache key
+
+		// First collection - computes and stores averages
+		result1 := gm.GetCurrentData(cacheKey)
+		assert.InDelta(t, 100.0, result1["0"].Power, 0.01)
+		assert.InDelta(t, 30.0, result1["0"].PowerPkg, 0.01)
+		assert.InDelta(t, 40.0, result1["0"].Engines["Render/3D"], 0.01)
+
+		// Second collection with no new sample (count unchanged, temp/mem still 0).
+		// Must carry the last average forward rather than blanking to zero.
+		result2 := gm.GetCurrentData(cacheKey)
+		assert.Equal(t, "GPU", result2["0"].Name, "Name should be preserved")
+		assert.InDelta(t, 100.0, result2["0"].Power, 0.01, "Should reuse last average power, not 0")
+		assert.InDelta(t, 30.0, result2["0"].PowerPkg, 0.01, "Should reuse last average package power, not 0")
+		assert.InDelta(t, 40.0, result2["0"].Engines["Render/3D"], 0.01, "Should reuse last average engine usage")
+	})
+
 	t.Run("tracks separate averages per cache key", func(t *testing.T) {
 		gm := &GPUManager{
 			GpuDataMap: map[string]*system.GPUData{

agent/handlers.go

@@ -51,6 +51,7 @@ func NewHandlerRegistry() *HandlerRegistry {
 	registry.Register(common.GetContainerInfo, &GetContainerInfoHandler{})
 	registry.Register(common.GetSmartData, &GetSmartDataHandler{})
 	registry.Register(common.GetSystemdInfo, &GetSystemdInfoHandler{})
+	registry.Register(common.GetZfsData, &GetZfsDataHandler{})
 
 	return registry
 }
@@ -178,6 +179,23 @@ func (h *GetSmartDataHandler) Handle(hctx *HandlerContext) error {
 	}, hctx.RequestID)
 }
 
+////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////
+
+// GetZfsDataHandler handles ZFS detail data requests
+type GetZfsDataHandler struct{}
+
+func (h *GetZfsDataHandler) Handle(hctx *HandlerContext) error {
+	if hctx.Agent.storagePoolManager == nil {
+		return hctx.SendResponse(nil, hctx.RequestID)
+	}
+	var req common.ZfsDataRequest
+	if err := cbor.Unmarshal(hctx.Request.Data, &req); err != nil {
+		return err
+	}
+	return hctx.SendResponse(hctx.Agent.storagePoolManager.GetDetail(req.Force), hctx.RequestID)
+}
+
 ////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////

agent/handlers_test.go

@@ -4,8 +4,10 @@ package agent
 
 import (
 	"testing"
+	"time"
 
 	"github.com/fxamacker/cbor/v2"
+	"github.com/henrygd/beszel/agent/zfs"
 	"github.com/henrygd/beszel/internal/common"
 	"github.com/henrygd/beszel/internal/entities/smart"
 	"github.com/stretchr/testify/assert"
@@ -30,6 +32,32 @@ func TestNewAgentResponseSmartData(t *testing.T) {
 	assert.True(t, response.SmartComplete)
 }
 
+func TestGetZfsDataHandlerForceRefresh(t *testing.T) {
+	poolCalls := 0
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) {
+		poolCalls++
+		return []zfs.PoolStat{{Name: "tank", Alloc: uint64(poolCalls)}}, nil
+	}
+	zm.backends[0].poolStatusesFn = func() ([]zfs.PoolStatus, error) { return nil, nil }
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) { return nil, nil }
+	zm.GetDetail(false)
+
+	requestData, err := cbor.Marshal(common.ZfsDataRequest{Force: true})
+	assert.NoError(t, err)
+	ctx := &HandlerContext{
+		Agent: &Agent{storagePoolManager: zm},
+		Request: &common.HubRequest[cbor.RawMessage]{
+			Action: common.GetZfsData,
+			Data:   requestData,
+		},
+		SendResponse: func(any, *uint32) error { return nil },
+	}
+
+	assert.NoError(t, (&GetZfsDataHandler{}).Handle(ctx))
+	assert.Equal(t, 2, poolCalls)
+}
+
 func (m *MockHandler) Handle(ctx *HandlerContext) error {
 	if m.handleFunc != nil {
 		return m.handleFunc(ctx)

agent/mdraid_linux.go

@@ -17,15 +17,17 @@ import (
 var mdraidSysfsRoot = "/sys"
 
 type mdraidHealth struct {
-	level         string
+	level          string
-	arrayState    string
+	arrayState     string
-	degraded      uint64
+	degraded       uint64
-	raidDisks     uint64
+	faultyDisks    uint64
-	syncAction    string
+	populatedDisks uint64
-	syncCompleted string
+	raidDisks      uint64
-	syncSpeed     string
+	syncAction     string
-	mismatchCnt   uint64
+	syncCompleted  string
-	capacity      uint64
+	syncSpeed      string
+	mismatchCnt    uint64
+	capacity       uint64
 }
 
 // scanMdraidDevices discovers Linux md arrays exposed in sysfs.
@@ -92,6 +94,9 @@ func (sm *SmartManager) collectMdraidHealth(deviceInfo *DeviceInfo) (bool, error
 	if health.degraded > 0 {
 		attrs = append(attrs, &smart.SmartAttribute{Name: "Degraded", RawValue: health.degraded})
 	}
+	if health.faultyDisks > 0 {
+		attrs = append(attrs, &smart.SmartAttribute{Name: "FaultyDisks", RawValue: health.faultyDisks})
+	}
 	if health.syncAction != "" {
 		attrs = append(attrs, &smart.SmartAttribute{Name: "SyncAction", RawString: health.syncAction})
 	}
@@ -152,6 +157,7 @@ func readMdraidHealth(blockName string) (mdraidHealth, bool) {
 	if val, ok := utils.ReadUintFile(filepath.Join(mdDir, "degraded")); ok {
 		out.degraded = val
 	}
+	out.faultyDisks, out.populatedDisks = countMdraidMemberStates(blockName, mdraidSysfsRoot)
 	if val, ok := utils.ReadUintFile(filepath.Join(mdDir, "mismatch_cnt")); ok {
 		out.mismatchCnt = val
 	}
@@ -177,7 +183,19 @@ func mdraidSmartStatus(health mdraidHealth) string {
 	case "resync", "recover", "reshape":
 		return "WARNING"
 	}
+	// Use actual faulty member count rather than the degraded counter, which
+	// equals raid_disks minus active_disks. On QNAP systems raid_disks may be
+	// set to a large value (e.g. 32) while only a few slots are ever used,
+	// making degraded misleadingly large despite zero failed disks.
+	if health.faultyDisks > 0 {
+		return "FAILED"
+	}
 	if health.degraded > 0 {
+		if isSparseSlotDegraded(health) {
+			// A sysfs snapshot cannot distinguish reserved slots from a removed
+			// member on sparse arrays, so report the ambiguity as a warning.
+			return "WARNING"
+		}
 		return "FAILED"
 	}
 	if health.mismatchCnt > 0 {
@@ -196,6 +214,43 @@ func mdraidSmartStatus(health mdraidHealth) string {
 	return "UNKNOWN"
 }
 
+// countMdraidMemberStates reads member device directories under
+// block/<name>/md and returns how many are explicitly marked "faulty", plus
+// how many are populated at all (regardless of state). populatedDisks lets
+// callers distinguish RAID slots that were never used (QNAP reserves far
+// more raid_disks than it ever populates) from members that went missing.
+func countMdraidMemberStates(blockName, root string) (faultyDisks, populatedDisks uint64) {
+	devDir := filepath.Join(root, "block", blockName, "md")
+	entries, err := os.ReadDir(devDir)
+	if err != nil {
+		return 0, 0
+	}
+	for _, ent := range entries {
+		if !strings.HasPrefix(ent.Name(), "dev-") {
+			continue
+		}
+		populatedDisks++
+		statePath := filepath.Join(devDir, ent.Name(), "state")
+		state := utils.ReadStringFile(statePath)
+		if strings.Contains(state, "faulty") {
+			faultyDisks++
+		}
+	}
+	return faultyDisks, populatedDisks
+}
+
+// isSparseSlotDegraded reports whether a non-zero "degraded" count may be
+// explained by RAID slots that were never populated. QNAP configures system
+// arrays with raid_disks set to a large fixed maximum (e.g. 32) far beyond the
+// handful of slots it ever populates, so sparse slots outnumber populated ones.
+func isSparseSlotDegraded(health mdraidHealth) bool {
+	if health.populatedDisks == 0 || health.raidDisks <= health.populatedDisks {
+		return false
+	}
+	sparseSlots := health.raidDisks - health.populatedDisks
+	return sparseSlots > health.populatedDisks
+}
+
 // isMdraidBlockName matches /dev/mdN-style block device names.
 func isMdraidBlockName(name string) bool {
 	if !strings.HasPrefix(name, "md") {

agent/mdraid_linux_test.go

@@ -40,6 +40,15 @@ func TestMdraidMockSysfsScanAndCollect(t *testing.T) {
 	write(filepath.Join(mdDir, "sync_completed"), "10%\n")
 	write(filepath.Join(mdDir, "sync_speed"), "100M\n")
 	write(filepath.Join(mdDir, "mismatch_cnt"), "0\n")
+
+	// Simulate two healthy member devices (no faulty state).
+	for _, dev := range []string{"dev-sda", "dev-sdb"} {
+		devPath := filepath.Join(mdDir, dev)
+		if err := os.MkdirAll(devPath, 0o755); err != nil {
+			t.Fatal(err)
+		}
+		write(filepath.Join(devPath, "state"), "in_sync\n")
+	}
 	write(filepath.Join(queueDir, "logical_block_size"), "512\n")
 	write(filepath.Join(tmp, "block", "md0", "size"), "2048\n")
 
@@ -81,15 +90,77 @@ func TestMdraidMockSysfsScanAndCollect(t *testing.T) {
 	}
 }
 
+func TestCountMdraidMemberStates(t *testing.T) {
+	tmp := t.TempDir()
+
+	write := func(path, content string) {
+		t.Helper()
+		if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+			t.Fatal(err)
+		}
+		if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	mdDir := filepath.Join(tmp, "block", "md0", "md")
+
+	// No dev-* entries: zero faulty, zero populated.
+	if faulty, populated := countMdraidMemberStates("md0", tmp); faulty != 0 || populated != 0 {
+		t.Fatalf("no members: got (faulty=%d populated=%d), want (0,0)", faulty, populated)
+	}
+
+	// Two healthy members.
+	write(filepath.Join(mdDir, "dev-sda", "state"), "in_sync\n")
+	write(filepath.Join(mdDir, "dev-sdb", "state"), "in_sync\n")
+	if faulty, populated := countMdraidMemberStates("md0", tmp); faulty != 0 || populated != 2 {
+		t.Fatalf("all in_sync: got (faulty=%d populated=%d), want (0,2)", faulty, populated)
+	}
+
+	// One faulty member.
+	write(filepath.Join(mdDir, "dev-sdb", "state"), "faulty\n")
+	if faulty, populated := countMdraidMemberStates("md0", tmp); faulty != 1 || populated != 2 {
+		t.Fatalf("one faulty: got (faulty=%d populated=%d), want (1,2)", faulty, populated)
+	}
+
+	// QNAP-style: 28 degraded slots but no dev-* entries for them, 4 in_sync.
+	write(filepath.Join(mdDir, "dev-sdb", "state"), "in_sync\n")
+	write(filepath.Join(mdDir, "dev-sdc", "state"), "in_sync\n")
+	write(filepath.Join(mdDir, "dev-sdd", "state"), "in_sync\n")
+	if faulty, populated := countMdraidMemberStates("md0", tmp); faulty != 0 || populated != 4 {
+		t.Fatalf("qnap sparse: got (faulty=%d populated=%d), want (0,4)", faulty, populated)
+	}
+}
+
 func TestMdraidSmartStatus(t *testing.T) {
 	if got := mdraidSmartStatus(mdraidHealth{arrayState: "inactive"}); got != "FAILED" {
 		t.Fatalf("mdraidSmartStatus(inactive) = %q, want FAILED", got)
 	}
-	if got := mdraidSmartStatus(mdraidHealth{arrayState: "active", degraded: 1, syncAction: "recover"}); got != "WARNING" {
+	if got := mdraidSmartStatus(mdraidHealth{arrayState: "active", degraded: 1, faultyDisks: 1, syncAction: "recover"}); got != "WARNING" {
 		t.Fatalf("mdraidSmartStatus(degraded+recover) = %q, want WARNING", got)
 	}
-	if got := mdraidSmartStatus(mdraidHealth{arrayState: "active", degraded: 1}); got != "FAILED" {
+	if got := mdraidSmartStatus(mdraidHealth{arrayState: "active", degraded: 1, faultyDisks: 1}); got != "FAILED" {
-		t.Fatalf("mdraidSmartStatus(degraded) = %q, want FAILED", got)
+		t.Fatalf("mdraidSmartStatus(degraded+faulty) = %q, want FAILED", got)
+	}
+	// QNAP-style: raid_disks=32 but only 4 populated; degraded=28 but no faulty devices.
+	if got := mdraidSmartStatus(mdraidHealth{arrayState: "clean", degraded: 28, faultyDisks: 0, raidDisks: 32, populatedDisks: 4}); got != "WARNING" {
+		t.Fatalf("mdraidSmartStatus(qnap sparse) = %q, want WARNING", got)
+	}
+	// A member disappearing from the same sparse array is indistinguishable
+	// from another reserved slot, so it must not be reported as healthy.
+	if got := mdraidSmartStatus(mdraidHealth{arrayState: "clean", degraded: 29, faultyDisks: 0, raidDisks: 32, populatedDisks: 3}); got != "WARNING" {
+		t.Fatalf("mdraidSmartStatus(qnap sparse missing member) = %q, want WARNING", got)
+	}
+	// A genuinely missing member (removed dev-* entry, not just an unpopulated
+	// QNAP reserve slot) must still fail: raid_disks=4, only 3 populated, all
+	// of them in_sync, so faultyDisks==0 but degraded==1.
+	if got := mdraidSmartStatus(mdraidHealth{arrayState: "clean", degraded: 1, faultyDisks: 0, raidDisks: 4, populatedDisks: 3}); got != "FAILED" {
+		t.Fatalf("mdraidSmartStatus(missing member) = %q, want FAILED", got)
+	}
+	// Degraded with no member-state info at all (e.g. sysfs read failed) must
+	// still fail rather than being silently treated as a sparse QNAP array.
+	if got := mdraidSmartStatus(mdraidHealth{arrayState: "clean", degraded: 1, faultyDisks: 0, raidDisks: 4, populatedDisks: 0}); got != "FAILED" {
+		t.Fatalf("mdraidSmartStatus(degraded, no member info) = %q, want FAILED", got)
 	}
 	if got := mdraidSmartStatus(mdraidHealth{arrayState: "active", syncAction: "recover"}); got != "WARNING" {
 		t.Fatalf("mdraidSmartStatus(recover) = %q, want WARNING", got)

agent/sensors_test.go

@@ -602,8 +602,9 @@ func TestUpdateTemperaturesSkipsOnTimeout(t *testing.T) {
 		},
 	}
 
+	originalGetSensorTemps := getSensorTemps
 	t.Cleanup(func() {
-		getSensorTemps = sensors.TemperaturesWithContext
+		getSensorTemps = originalGetSensorTemps
 	})
 	getSensorTemps = func(ctx context.Context) ([]sensors.TemperatureStat, error) {
 		time.Sleep(50 * time.Millisecond)

agent/sensors_windows.go

@@ -214,9 +214,12 @@ func (lhm *lhmProcess) getTemps(ctx context.Context) (temps []sensors.Temperatur
 	return temps, nil
 }
 
-// getSensorTemps attempts to pull sensor temperatures from the embedded LHM process.
+// getSensorTemps is a variable so tests can replace the platform sensor collector.
+var getSensorTemps = getWindowsSensorTemps
+
+// getWindowsSensorTemps attempts to pull sensor temperatures from the embedded LHM process.
 // NB: LibreHardwareMonitorLib requires admin privileges to access all available sensors.
-func getSensorTemps(ctx context.Context) (temps []sensors.TemperatureStat, err error) {
+func getWindowsSensorTemps(ctx context.Context) (temps []sensors.TemperatureStat, err error) {
 	defer func() {
 		if err != nil {
 			slog.Debug("Error reading sensors", "err", err)

agent/server.go

@@ -265,6 +265,5 @@ func (a *Agent) StopServer() error {
 	slog.Info("Stopping SSH server")
 	_ = a.server.Close()
 	a.server = nil
-	a.connectionManager.eventChan <- SSHDisconnect
 	return nil
 }

agent/server_test.go

@@ -198,6 +198,28 @@ func TestStartServerDisableSSH(t *testing.T) {
 	assert.Contains(t, err.Error(), "SSH disabled")
 }
 
+func TestStopServerDoesNotBlockWhenEventQueueFull(t *testing.T) {
+	agent := createTestAgent(t)
+	agent.server = &ssh.Server{}
+	agent.connectionManager.eventChan = make(chan ConnectionEvent, 1)
+	agent.connectionManager.eventChan <- WebSocketConnect
+
+	done := make(chan error, 1)
+	go func() {
+		done <- agent.StopServer()
+	}()
+
+	select {
+	case err := <-done:
+		require.NoError(t, err)
+	case <-time.After(time.Second):
+		t.Fatal("StopServer blocked on the connection event queue")
+	}
+
+	assert.Nil(t, agent.server)
+	assert.Equal(t, WebSocketConnect, <-agent.connectionManager.eventChan)
+}
+
 /////////////////////////////////////////////////////////////////
 //////////////////// ParseKeys Tests ////////////////////////////
 /////////////////////////////////////////////////////////////////

agent/smart_test.go

@@ -4,6 +4,7 @@ package agent
 
 import (
 	"errors"
+	"fmt"
 	"os"
 	"path/filepath"
 	"testing"
@@ -88,6 +89,31 @@ func TestParseSmartForSata(t *testing.T) {
 	}
 }
 
+func TestParseSmartForSataPreservesFailedAndUnknownStatus(t *testing.T) {
+	for _, test := range []struct {
+		name        string
+		temperature int
+		want        string
+	}{
+		{name: "failed", temperature: 30, want: "FAILED"},
+		{name: "unknown", want: "UNKNOWN"},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			jsonPayload := []byte(fmt.Sprintf(`{
+				"device": {"name": "/dev/sda", "type": "sat"},
+				"serial_number": "PRESERVE%s",
+				"temperature": {"current": %d},
+				"ata_smart_attributes": {"table": [{"id": 197, "raw": {"value": 1, "string": "1"}}]}
+			}`, test.name, test.temperature))
+
+			sm := &SmartManager{SmartDataMap: make(map[string]*smart.SmartData)}
+			hasData, _ := sm.parseSmartForSata(jsonPayload, "")
+			require.True(t, hasData)
+			assert.Equal(t, test.want, sm.SmartDataMap["PRESERVE"+test.name].SmartStatus)
+		})
+	}
+}
+
 func TestParseSmartForSataDeviceStatisticsTemperature(t *testing.T) {
 	jsonPayload := []byte(`{
 		"smartctl": {"exit_status": 0},

agent/storage_pool.go

@@ -0,0 +1,462 @@
+package agent
+
+import (
+	"errors"
+	"log/slog"
+	"os/exec"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/henrygd/beszel/agent/btrfs"
+	"github.com/henrygd/beszel/agent/zfs"
+	"github.com/henrygd/beszel/internal/entities/system"
+	zfsentity "github.com/henrygd/beszel/internal/entities/zfs"
+)
+
+// zfsDatasetUsage holds usage values for a ZFS dataset mountpoint.
+type zfsDatasetUsage struct {
+	used  uint64
+	avail uint64
+}
+
+// datasetUsageRefreshInterval controls how often `zfs list` is re-run for the
+// mountpoint usage map. Dataset inventory changes rarely.
+const datasetUsageRefreshInterval = 5 * time.Minute
+
+// poolStatsRefreshInterval controls how often `zpool list` is re-run for pool
+// capacity. Health and I/O are read from procfs on Linux, so the utility only
+// needs to refresh slow-moving space accounting.
+const poolStatsRefreshInterval = time.Minute
+
+// btrfsFilesystems is the btrfs source; overridable in tests.
+var btrfsFilesystems = btrfs.Filesystems
+
+type poolKernelSample struct {
+	nread  uint64
+	nwrite uint64
+	at     time.Time
+}
+
+// StoragePoolManager combines independent backend inventories. Metrics and
+// dataset usage require the agent lock; GetDetail is safe for concurrent calls.
+type StoragePoolManager struct {
+	backends       []*poolBackend
+	detailInterval time.Duration
+}
+
+// poolBackend owns one backend's collectors and caches. Collector functions
+// are immutable after construction and may run concurrently for metrics/details.
+type poolBackend struct {
+	name           string
+	poolStatsFn    func() ([]zfs.PoolStat, error)       // capacity/health source
+	datasetsFn     func() ([]zfs.Dataset, error)        // dataset inventory source
+	kernelStatsFn  func() ([]zfs.PoolKernelStat, error) // procfs pool state/I/O source
+	poolStatusesFn func() ([]zfs.PoolStatus, error)     // scrub/vdev detail source
+
+	poolData      []zfs.PoolStat // cached pool inventory (TTL below)
+	lastPoolStats time.Time
+	kernelSamples map[string]poolKernelSample
+
+	datasetUsage     map[string]zfsDatasetUsage // mountpoint -> usage
+	lastUsageRefresh time.Time
+
+	// Detail data (pools, vdevs, scrub, datasets) is cached and refreshed on
+	// an interval. Accessed from handler goroutines, so it is mutex-protected.
+	detailMu          sync.Mutex
+	detail            *zfsentity.ZfsData
+	lastDetailRefresh time.Time
+	detailFailed      bool
+}
+
+func newStoragePoolManager() *StoragePoolManager {
+	return &StoragePoolManager{
+		backends:       []*poolBackend{newZfsBackend(), newBtrfsBackend()},
+		detailInterval: time.Hour,
+	}
+}
+
+func newZfsBackend() *poolBackend {
+	return &poolBackend{
+		name:           "zfs",
+		poolStatsFn:    optionalPoolSource(zfs.PoolStats),
+		datasetsFn:     optionalPoolSource(zfs.Datasets),
+		kernelStatsFn:  optionalPoolSource(zfs.PoolKernelStats),
+		poolStatusesFn: optionalPoolSource(zfs.PoolStatuses),
+	}
+}
+
+func newBtrfsBackend() *poolBackend {
+	return &poolBackend{
+		name:           "btrfs",
+		poolStatsFn:    btrfsSource(btrfsPoolStats),
+		kernelStatsFn:  btrfsSource(btrfsKernelStats),
+		poolStatusesFn: btrfsSource(btrfsPoolStatuses),
+	}
+}
+
+// datasets is optional: only backends that expose datasets provide a collector.
+func (b *poolBackend) datasets() ([]zfs.Dataset, error) {
+	if b.datasetsFn == nil {
+		return nil, nil
+	}
+	return b.datasetsFn()
+}
+
+// A missing utility/interface is a successfully observed absent backend.
+func optionalPoolSource[T any](source func() ([]T, error)) func() ([]T, error) {
+	return func() ([]T, error) {
+		items, err := source()
+		if errors.Is(err, zfs.ErrNoZfs) || errors.Is(err, exec.ErrNotFound) || errors.Is(err, errors.ErrUnsupported) {
+			return nil, nil
+		}
+		return items, err
+	}
+}
+
+func btrfsSource[T any](convert func(btrfs.Filesystem) T) func() ([]T, error) {
+	return func() ([]T, error) {
+		filesystems, err := optionalPoolSource(btrfsFilesystems)()
+		if err != nil {
+			return nil, err
+		}
+		items := make([]T, 0, len(filesystems))
+		for _, fs := range filesystems {
+			items = append(items, convert(fs))
+		}
+		return items, nil
+	}
+}
+
+// Update refreshes systemStats.ZfsPools with the latest pool data. I/O
+// throughput and health come from inexpensive kernel kstats on Linux. Pool
+// capacity and dataset usage come from separately cached utility calls. The
+// pool map is empty when both backends are absent.
+func (m *StoragePoolManager) Update(systemStats *system.Stats) {
+	// Rebuild the combined map so successful pool removals clear old samples.
+	systemStats.ZfsPools = nil
+	for _, backend := range m.backends {
+		backend.updateBackendStats(systemStats)
+	}
+}
+
+func (b *poolBackend) updateBackendStats(systemStats *system.Stats) {
+	pools := b.poolStats()
+	if len(pools) == 0 {
+		b.kernelSamples = nil
+		return
+	}
+
+	kernelStats, ioRates := b.kernelStats()
+
+	if systemStats.ZfsPools == nil {
+		systemStats.ZfsPools = make(map[string]*system.ZfsPool, len(pools))
+	}
+	for i := range pools {
+		pool := &pools[i]
+		// Full precision, matching the dataset values below; the frontend
+		// formats any magnitude.
+		stats := &system.ZfsPool{
+			DisplayName: pool.DisplayName,
+			Raw:         pool.Raw,
+			Total:       float64(pool.Size) / (1024 * 1024 * 1024),
+			Used:        float64(pool.Alloc) / (1024 * 1024 * 1024),
+			Health:      pool.Health,
+		}
+		if kernel, exists := kernelStats[pool.Name]; exists && kernel.Health != "" {
+			stats.Health = kernel.Health
+		}
+		if io, exists := ioRates[pool.Name]; exists {
+			stats.ReadBytes = io.NRead
+			stats.WriteBytes = io.NWrite
+		}
+		slog.Debug("Storage pool sample", "backend", b.name, "pool", pool.Name, "health", stats.Health, "used_gb", stats.Used, "read_bps", stats.ReadBytes, "write_bps", stats.WriteBytes)
+		systemStats.ZfsPools[pool.Name] = stats
+	}
+
+}
+
+// poolStats returns the cached pool inventory, calling its collector at most
+// every poolStatsRefreshInterval. On failure the previous inventory is
+// retained and the refresh is retried on the next cadence.
+func (b *poolBackend) poolStats() []zfs.PoolStat {
+	if b.lastPoolStats.IsZero() || time.Since(b.lastPoolStats) >= poolStatsRefreshInterval {
+		pools, err := b.poolStatsFn()
+		if err != nil {
+			slog.Debug("Storage pool stats unavailable", "backend", b.name, "err", err)
+		} else {
+			b.poolData = pools
+		}
+		b.lastPoolStats = time.Now()
+	}
+	return b.poolData
+}
+
+// kernelStats reads cumulative pool counters and converts them to per-second
+// rates. Counter decreases indicate a pool export/import and reset the
+// baseline instead of producing an underflow spike.
+func (b *poolBackend) kernelStats() (map[string]zfs.PoolKernelStat, map[string]zfs.PoolIoStats) {
+	if b.kernelStatsFn == nil {
+		return nil, nil
+	}
+	stats, err := b.kernelStatsFn()
+	if err != nil {
+		slog.Debug("Storage pool kernel stats unavailable", "backend", b.name, "err", err)
+		return nil, nil
+	}
+	now := time.Now()
+	byName := make(map[string]zfs.PoolKernelStat, len(stats))
+	rates := make(map[string]zfs.PoolIoStats, len(stats))
+	nextSamples := make(map[string]poolKernelSample, len(stats))
+	for _, stat := range stats {
+		byName[stat.Name] = stat
+		if previous, ok := b.kernelSamples[stat.Name]; ok && now.After(previous.at) &&
+			stat.NRead >= previous.nread && stat.NWrite >= previous.nwrite {
+			seconds := now.Sub(previous.at).Seconds()
+			rates[stat.Name] = zfs.PoolIoStats{
+				NRead:  uint64(float64(stat.NRead-previous.nread) / seconds),
+				NWrite: uint64(float64(stat.NWrite-previous.nwrite) / seconds),
+			}
+		}
+		nextSamples[stat.Name] = poolKernelSample{nread: stat.NRead, nwrite: stat.NWrite, at: now}
+	}
+	b.kernelSamples = nextSamples
+	return byName, rates
+}
+
+// refreshDatasetUsage re-runs `zfs list` when the refresh window has elapsed
+// and rebuilds the mountpoint-keyed usage map.
+func (b *poolBackend) refreshDatasetUsage() {
+	if !b.lastUsageRefresh.IsZero() && time.Since(b.lastUsageRefresh) < datasetUsageRefreshInterval {
+		return
+	}
+	datasets, err := b.datasets()
+	if err != nil {
+		slog.Debug("Storage pool dataset usage unavailable", "backend", b.name, "err", err)
+	} else {
+		usage := make(map[string]zfsDatasetUsage, len(datasets))
+		for _, ds := range datasets {
+			if ds.Mountpoint != "" && ds.Mountpoint != "-" {
+				usage[ds.Mountpoint] = zfsDatasetUsage{used: ds.Used, avail: ds.Avail}
+			}
+		}
+		b.datasetUsage = usage
+	}
+	b.lastUsageRefresh = time.Now()
+}
+
+// DatasetUsage returns ZFS dataset usage keyed by mountpoint, refreshed at
+// most every datasetUsageRefreshInterval. On failure the previous map is
+// retained and a debug log is emitted.
+func (m *StoragePoolManager) DatasetUsage() map[string]zfsDatasetUsage {
+	for _, backend := range m.backends {
+		if backend.name == "zfs" {
+			backend.refreshDatasetUsage()
+			return backend.datasetUsage
+		}
+	}
+	return nil
+}
+
+// GetDetail combines backend snapshots, identifying successful inventories so
+// the hub can accept partial updates without deleting failed backend records.
+func (m *StoragePoolManager) GetDetail(force bool) *zfsentity.ZfsData {
+	data := &zfsentity.ZfsData{Complete: true}
+	for _, backend := range m.backends {
+		snapshot := backend.getBackendDetail(force, m.detailInterval)
+		data.Pools = append(data.Pools, snapshot.Pools...)
+		if snapshot.Complete {
+			data.CompleteBackends = append(data.CompleteBackends, backend.name)
+		} else {
+			data.Complete = false
+		}
+	}
+	return data
+}
+
+func (b *poolBackend) getBackendDetail(force bool, interval time.Duration) *zfsentity.ZfsData {
+	b.detailMu.Lock()
+	defer b.detailMu.Unlock()
+
+	if force || b.detailFailed || b.detail == nil || time.Since(b.lastDetailRefresh) >= interval {
+		if data, err := b.collectDetail(b.detail); err != nil {
+			b.detailFailed = true
+			slog.Debug("Storage pool detail collection failed", "backend", b.name, "err", err)
+			if b.detail == nil {
+				return &zfsentity.ZfsData{}
+			}
+			return &zfsentity.ZfsData{Pools: b.detail.Pools}
+		} else {
+			b.detailFailed = false
+			b.detail = data
+			b.lastDetailRefresh = time.Now()
+		}
+	}
+	if b.detail == nil {
+		return &zfsentity.ZfsData{}
+	}
+	return b.detail
+}
+
+// collectDetail builds a ZfsData payload from the current system state.
+func (b *poolBackend) collectDetail(previous *zfsentity.ZfsData) (*zfsentity.ZfsData, error) {
+	pools, err := b.poolStatsFn()
+	if err != nil {
+		return nil, err
+	}
+	if len(pools) == 0 {
+		return &zfsentity.ZfsData{Pools: []*zfsentity.PoolDetail{}, Complete: true}, nil
+	}
+
+	statuses, statusErr := b.poolStatusesFn()
+	if statusErr != nil {
+		slog.Debug("Storage pool status unavailable", "backend", b.name, "err", statusErr)
+	}
+	datasets, datasetsErr := b.datasets()
+	if datasetsErr != nil {
+		slog.Debug("Storage pool datasets unavailable", "backend", b.name, "err", datasetsErr)
+	}
+
+	statusByPool := make(map[string]zfs.PoolStatus, len(statuses))
+	for _, st := range statuses {
+		statusByPool[st.Name] = st
+	}
+
+	previousByPool := make(map[string]*zfsentity.PoolDetail)
+	if previous != nil {
+		for _, pool := range previous.Pools {
+			if pool != nil {
+				previousByPool[pool.Name] = pool
+			}
+		}
+	}
+
+	data := &zfsentity.ZfsData{Pools: make([]*zfsentity.PoolDetail, 0, len(pools)), Complete: true}
+	for i := range pools {
+		p := &pools[i]
+		detail := &zfsentity.PoolDetail{
+			DisplayName: p.DisplayName,
+			Raw:         p.Raw,
+			Name:        p.Name,
+			Health:      p.Health,
+			Size:        p.Size,
+			Alloc:       p.Alloc,
+			Free:        p.Free,
+		}
+		if st, ok := statusByPool[p.Name]; statusErr == nil && ok {
+			if st.Scrub.State != "" && st.Scrub.State != "NONE" {
+				detail.Scrub = &zfsentity.Scrub{
+					State:    st.Scrub.State,
+					Progress: st.Scrub.Progress,
+					Errors:   st.Scrub.Errors,
+				}
+			}
+			for _, v := range st.Vdevs {
+				detail.Vdevs = append(detail.Vdevs, &zfsentity.Vdev{
+					Name:         v.Name,
+					State:        v.State,
+					ReadErrs:     v.ReadErrs,
+					WriteErrs:    v.WriteErrs,
+					ChecksumErrs: v.ChecksumErrs,
+				})
+			}
+		} else {
+			if cached := previousByPool[p.Name]; cached != nil {
+				detail.Scrub = cached.Scrub
+				detail.Vdevs = cached.Vdevs
+			}
+		}
+		if datasetsErr == nil {
+			foundDataset := false
+			for _, ds := range datasets {
+				if poolOfDataset(ds.Name) == p.Name {
+					foundDataset = true
+					detail.Datasets = append(detail.Datasets, &zfsentity.Dataset{
+						Name:       ds.Name,
+						Used:       ds.Used,
+						Avail:      ds.Avail,
+						Mountpoint: ds.Mountpoint,
+					})
+				}
+			}
+			if !foundDataset {
+				if cached := previousByPool[p.Name]; cached != nil {
+					detail.Datasets = cached.Datasets
+				}
+			}
+		} else if cached := previousByPool[p.Name]; cached != nil {
+			detail.Datasets = cached.Datasets
+		}
+		data.Pools = append(data.Pools, detail)
+	}
+	return data, nil
+}
+
+// poolOfDataset returns the pool name for a dataset name (everything before
+// the first '/'). Datasets without a separator belong to a pool of the same
+// name.
+func poolOfDataset(name string) string {
+	if idx := strings.IndexByte(name, '/'); idx >= 0 {
+		return name[:idx]
+	}
+	return name
+}
+
+// ZfsMountpoints returns the set of mountpoints backed by ZFS datasets.
+func (m *StoragePoolManager) ZfsMountpoints() map[string]bool {
+	usage := m.DatasetUsage()
+	mountpoints := make(map[string]bool, len(usage))
+	for mountpoint := range usage {
+		mountpoints[mountpoint] = true
+	}
+	return mountpoints
+}
+
+func btrfsPoolStats(fs btrfs.Filesystem) zfs.PoolStat {
+	return zfs.PoolStat{MountID: fs.MountID, IODevice: fs.IODevice, Raw: fs.Raw, DisplayName: fs.Name, Name: "b:" + fs.UUID, Size: fs.Size, Alloc: fs.Alloc, Free: fs.Size - min(fs.Alloc, fs.Size), Health: fs.Health}
+}
+
+func btrfsKernelStats(fs btrfs.Filesystem) zfs.PoolKernelStat {
+	return zfs.PoolKernelStat{Name: "b:" + fs.UUID, Health: fs.Health, NRead: fs.NRead, NWrite: fs.NWrite}
+}
+
+func btrfsPoolStatuses(fs btrfs.Filesystem) zfs.PoolStatus {
+	status := zfs.PoolStatus{Name: "b:" + fs.UUID, State: fs.Health, Scrub: zfs.ScrubStatus{State: "NONE"}}
+	for _, dev := range fs.Devices {
+		status.Vdevs = append(status.Vdevs, zfs.VdevStatus{
+			Name: dev.Name, State: dev.State,
+			ReadErrs: dev.ReadErrs, WriteErrs: dev.WriteErrs, ChecksumErrs: dev.CorruptionErrs,
+		})
+	}
+	return status
+}
+
+// markDuplicateCharts leaves pool telemetry and detail intact, but tells the
+// hub which charts already have a filesystem equivalent. Only exact kernel
+// filesystem and I/O-device matches qualify; labels are never used.
+func (m *StoragePoolManager) markDuplicateCharts(stats *system.Stats, filesystems map[string]*system.FsStats, mountID func(string) string) {
+	identities := make(map[string]string, len(filesystems))
+	for device, fs := range filesystems {
+		if fs.DiskTotal > 0 {
+			identities[device] = mountID(fs.Mountpoint)
+		}
+	}
+	for _, backend := range m.backends {
+		for _, pool := range backend.poolData {
+			sample := stats.ZfsPools[pool.Name]
+			if sample == nil || pool.MountID == "" {
+				continue
+			}
+			for device, identity := range identities {
+				if identity != pool.MountID {
+					continue
+				}
+				// Raw physical usage is not equivalent to a filesystem usage chart.
+				sample.HideUsage = !pool.Raw
+				if pool.IODevice != "" && pool.IODevice == device {
+					sample.HideIO = true
+				}
+			}
+		}
+	}
+}

agent/storage_pool_test.go

@@ -0,0 +1,520 @@
+//go:build testing
+
+package agent
+
+import (
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/henrygd/beszel/agent/btrfs"
+	"github.com/henrygd/beszel/agent/zfs"
+	"github.com/henrygd/beszel/internal/entities/system"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestOptionalPoolSource(t *testing.T) {
+	failure := errors.New("timeout")
+	for _, err := range []error{nil, zfs.ErrNoZfs, fmt.Errorf("zpool: %w", exec.ErrNotFound), errors.ErrUnsupported, failure} {
+		_, got := optionalPoolSource(func() ([]zfs.PoolStat, error) { return nil, err })()
+		if err == failure {
+			assert.ErrorIs(t, got, failure)
+		} else {
+			assert.NoError(t, got)
+		}
+	}
+}
+
+type poolTestBackend struct {
+	name  string
+	err   error
+	alloc uint64
+	read  uint64
+	empty bool
+}
+
+func (state *poolTestBackend) backend() *poolBackend {
+	name := "zfs"
+	if strings.HasPrefix(state.name, "b:") {
+		name = "btrfs"
+	}
+	return &poolBackend{
+		name: name,
+		poolStatsFn: func() ([]zfs.PoolStat, error) {
+			if state.empty {
+				return nil, state.err
+			}
+			return []zfs.PoolStat{{Name: state.name, Size: 100, Alloc: state.alloc}}, state.err
+		},
+		kernelStatsFn: func() ([]zfs.PoolKernelStat, error) {
+			return []zfs.PoolKernelStat{{Name: state.name, NRead: state.read}}, state.err
+		},
+		poolStatusesFn: func() ([]zfs.PoolStatus, error) { return nil, nil },
+		datasetsFn:     func() ([]zfs.Dataset, error) { return nil, nil },
+	}
+}
+
+func TestIndependentPoolBackendCaches(t *testing.T) {
+	for _, failed := range []int{0, 1} {
+		t.Run([]string{"zfs", "btrfs"}[failed], func(t *testing.T) {
+			states := []*poolTestBackend{{name: "tank", alloc: 10}, {name: "b:uuid", alloc: 10}}
+			managers := []*poolBackend{states[0].backend(), states[1].backend()}
+			zm := &StoragePoolManager{backends: managers, detailInterval: time.Hour}
+			var stats system.Stats
+			zm.Update(&stats)
+			require.Len(t, stats.ZfsPools, 2)
+			require.True(t, zm.GetDetail(true).Complete)
+			baseline := poolKernelSample{at: time.Now().Add(-time.Second)}
+			for i, m := range managers {
+				m.lastPoolStats = time.Time{}
+				m.kernelSamples[states[i].name] = baseline
+				states[i].alloc = 20
+				states[i].read = 100
+			}
+			states[failed].err = errors.New("collection failed")
+			zm.Update(&stats)
+			healthy := 1 - failed
+			assert.Equal(t, uint64(10), managers[failed].poolData[0].Alloc)
+			assert.Equal(t, uint64(20), managers[healthy].poolData[0].Alloc)
+			assert.Equal(t, baseline, managers[failed].kernelSamples[states[failed].name])
+			assert.Zero(t, stats.ZfsPools[states[failed].name].ReadBytes)
+			assert.Positive(t, stats.ZfsPools[states[healthy].name].ReadBytes)
+			partial := zm.GetDetail(true)
+			assert.False(t, partial.Complete)
+			assert.False(t, partial.CanRefreshPool(states[failed].name))
+			assert.True(t, partial.CanRefreshPool(states[healthy].name))
+			assert.Equal(t, uint64(10), partial.Pools[failed].Alloc)
+			assert.Equal(t, uint64(20), partial.Pools[healthy].Alloc)
+			assert.False(t, zm.GetDetail(false).Complete, "a failed forced refresh must not become complete from cache")
+
+			// Successful empty inventory removes only the healthy backend's pool.
+			states[healthy].empty = true
+			managers[healthy].lastPoolStats = time.Time{}
+			zm.Update(&stats)
+			require.Len(t, stats.ZfsPools, 1)
+			assert.Contains(t, stats.ZfsPools, states[failed].name)
+			partial = zm.GetDetail(true)
+			require.Len(t, partial.Pools, 1)
+			assert.True(t, partial.CanRefreshPool(states[healthy].name))
+
+			// Recovery uses the retained I/O baseline, then normal removal works.
+			states[failed].err = nil
+			managers[failed].lastPoolStats = time.Time{}
+			zm.Update(&stats)
+			assert.Positive(t, stats.ZfsPools[states[failed].name].ReadBytes)
+			assert.True(t, zm.GetDetail(true).Complete)
+			states[failed].empty = true
+			managers[failed].lastPoolStats = time.Time{}
+			zm.Update(&stats)
+			assert.Empty(t, stats.ZfsPools)
+			assert.Empty(t, zm.GetDetail(true).Pools)
+		})
+	}
+}
+
+func TestIndependentBackendsWithoutCache(t *testing.T) {
+	z := &poolTestBackend{name: "tank", err: errors.New("ZFS failure")}
+	b := &poolTestBackend{name: "b:uuid", alloc: 20}
+	zm := &StoragePoolManager{backends: []*poolBackend{z.backend(), b.backend()}, detailInterval: time.Hour}
+	var stats system.Stats
+	zm.Update(&stats)
+	require.Len(t, stats.ZfsPools, 1)
+	assert.Contains(t, stats.ZfsPools, "b:uuid")
+	detail := zm.GetDetail(true)
+	require.Len(t, detail.Pools, 1)
+	assert.False(t, detail.Complete)
+	assert.Equal(t, []string{"btrfs"}, detail.CompleteBackends)
+}
+
+func TestConcurrentBackendDetailsAndMetrics(t *testing.T) {
+	zm := &StoragePoolManager{backends: []*poolBackend{(&poolTestBackend{name: "tank"}).backend(), (&poolTestBackend{name: "b:uuid"}).backend()}, detailInterval: time.Hour}
+	var wg sync.WaitGroup
+	for i := 0; i < 3; i++ {
+		wg.Add(1)
+		go func(metrics bool) {
+			defer wg.Done()
+			for j := 0; j < 10; j++ {
+				if metrics {
+					zm.Update(&system.Stats{})
+				} else {
+					zm.GetDetail(true)
+				}
+			}
+		}(i == 0)
+	}
+	wg.Wait()
+}
+
+func TestStoragePoolBackendOrder(t *testing.T) {
+	z := (&poolTestBackend{name: "tank"}).backend()
+	b := (&poolTestBackend{name: "b:uuid"}).backend()
+	b.datasetsFn = nil // Btrfs does not expose datasets.
+	z.datasetsFn = func() ([]zfs.Dataset, error) {
+		return []zfs.Dataset{{Name: "tank/data", Mountpoint: "/tank", Used: 10}}, nil
+	}
+	m := &StoragePoolManager{backends: []*poolBackend{b, z}, detailInterval: time.Hour}
+	var stats system.Stats
+	m.Update(&stats)
+	require.Len(t, stats.ZfsPools, 2)
+	detail := m.GetDetail(true)
+	require.True(t, detail.Complete)
+	assert.Equal(t, []string{"btrfs", "zfs"}, detail.CompleteBackends)
+	assert.Empty(t, detail.Pools[0].Datasets)
+	assert.Len(t, detail.Pools[1].Datasets, 1)
+	assert.Equal(t, uint64(10), m.DatasetUsage()["/tank"].used)
+
+	b.poolData[0].MountID = "uuid"
+	b.poolData[0].IODevice = "sda"
+	calls := 0
+	m.markDuplicateCharts(&stats, map[string]*system.FsStats{
+		"sda": {Mountpoint: "/", DiskTotal: 100},
+	}, func(string) string { calls++; return "uuid" })
+	assert.Equal(t, 1, calls, "resolve each filesystem once across all backends")
+	assert.True(t, stats.ZfsPools["b:uuid"].HideUsage)
+	assert.True(t, stats.ZfsPools["b:uuid"].HideIO)
+}
+
+func TestUpdatePopulatesZfsPools(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) {
+		return []zfs.PoolStat{{Name: "tank", Size: 23999000000000, Alloc: 12000000000000, Free: 11999000000000, Health: "DEGRADED"}}, nil
+	}
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) {
+		return []zfs.Dataset{
+			{Name: "tank/apps", Used: 5000000000000, Avail: 11999000000000, Mountpoint: "/tank/apps"},
+			{Name: "tank/backup", Used: 6000000000000, Avail: 11999000000000, Mountpoint: "/tank/backup"},
+			// Small zvol (Proxmox VM EFI disk): must not round to zero.
+			{Name: "rpool/vm-100-disk-2", Used: 4194304, Avail: 0, Mountpoint: "-"},
+		}, nil
+	}
+	var kernelCalls int
+	zm.backends[0].kernelStatsFn = func() ([]zfs.PoolKernelStat, error) {
+		kernelCalls++
+		return []zfs.PoolKernelStat{{
+			Name: "tank", Health: "ONLINE",
+			NRead: uint64(kernelCalls-1) * 1250, NWrite: uint64(kernelCalls-1) * 5120,
+		}}, nil
+	}
+
+	var stats system.Stats
+	// The first kernel sample establishes the cumulative-counter baseline.
+	zm.Update(&stats)
+	zm.backends[0].kernelSamples["tank"] = poolKernelSample{at: time.Now().Add(-time.Second)}
+	zm.Update(&stats)
+	require.NotNil(t, stats.ZfsPools)
+	require.Contains(t, stats.ZfsPools, "tank")
+	assert.InDelta(t, 22350.8105, stats.ZfsPools["tank"].Total, 0.0001) // Size in GiB
+	assert.InDelta(t, 11175.8709, stats.ZfsPools["tank"].Used, 0.0001)  // Alloc in GiB
+	assert.Equal(t, "ONLINE", stats.ZfsPools["tank"].Health)
+	assert.InDelta(t, 1250, stats.ZfsPools["tank"].ReadBytes, 5)
+	assert.InDelta(t, 5120, stats.ZfsPools["tank"].WriteBytes, 5)
+
+}
+
+// TestUpdateKernelStatsMissing verifies pools without a kernel sample report zero
+// I/O instead of erroring.
+func TestUpdateKernelStatsMissing(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) {
+		return []zfs.PoolStat{{Name: "tank", Size: 1, Alloc: 1, Health: "ONLINE"}}, nil
+	}
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) { return nil, nil }
+	zm.backends[0].kernelStatsFn = func() ([]zfs.PoolKernelStat, error) {
+		return nil, zfs.ErrNoZfs
+	}
+
+	var stats system.Stats
+	zm.Update(&stats)
+	require.NotNil(t, stats.ZfsPools)
+	assert.Equal(t, uint64(0), stats.ZfsPools["tank"].ReadBytes)
+	assert.Equal(t, uint64(0), stats.ZfsPools["tank"].WriteBytes)
+}
+
+func TestUpdateKernelCounterReset(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) {
+		return []zfs.PoolStat{{Name: "tank", Health: "ONLINE"}}, nil
+	}
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) { return nil, nil }
+	zm.backends[0].kernelSamples = map[string]poolKernelSample{
+		"tank": {nread: 100, nwrite: 200, at: time.Now().Add(-time.Second)},
+	}
+	zm.backends[0].kernelStatsFn = func() ([]zfs.PoolKernelStat, error) {
+		return []zfs.PoolKernelStat{{Name: "tank", Health: "ONLINE", NRead: 10, NWrite: 20}}, nil
+	}
+
+	var stats system.Stats
+	zm.Update(&stats)
+	assert.Equal(t, uint64(0), stats.ZfsPools["tank"].ReadBytes)
+	assert.Equal(t, uint64(0), stats.ZfsPools["tank"].WriteBytes)
+}
+
+func TestUpdateNoZfs(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	calls := 0
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) {
+		calls++
+		return nil, zfs.ErrNoZfs
+	}
+
+	var stats system.Stats
+	zm.Update(&stats)
+	zm.Update(&stats)
+	assert.Nil(t, stats.ZfsPools)
+	assert.Equal(t, 1, calls, "failed pool discovery should be cached until the next refresh interval")
+}
+
+func TestUpdateEmptyPools(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	calls := 0
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) {
+		calls++
+		return nil, nil
+	}
+
+	var stats system.Stats
+	zm.Update(&stats)
+	zm.Update(&stats)
+	assert.Nil(t, stats.ZfsPools)
+	assert.Equal(t, 1, calls, "an empty pool inventory should be cached until the next refresh interval")
+}
+
+func TestDatasetUsage(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	calls := 0
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) {
+		calls++
+		return []zfs.Dataset{
+			{Name: "tank", Used: 12000000000000, Avail: 11999000000000, Mountpoint: "/tank"},
+			{Name: "tank/apps", Used: 1000000000000, Avail: 11999000000000, Mountpoint: "/tank/apps"},
+			{Name: "rpool", Used: 900000000000, Avail: 300000000000, Mountpoint: "-"}, // zvol/unmounted: excluded
+		}, nil
+	}
+
+	usage := zm.DatasetUsage()
+	require.Len(t, usage, 2)
+	assert.Equal(t, zfsDatasetUsage{used: 12000000000000, avail: 11999000000000}, usage["/tank"])
+	assert.Equal(t, zfsDatasetUsage{used: 1000000000000, avail: 11999000000000}, usage["/tank/apps"])
+	assert.Equal(t, 1, calls)
+
+	// Second call within the refresh window must not re-run the collector.
+	zm.DatasetUsage()
+	assert.Equal(t, 1, calls)
+}
+
+func TestDatasetUsageRefreshOnErrorKeepsPrevious(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) {
+		return []zfs.Dataset{{Name: "tank", Used: 1, Avail: 1, Mountpoint: "/tank"}}, nil
+	}
+	assert.Len(t, zm.DatasetUsage(), 1)
+
+	// Force refresh window expiry, then a failing collector.
+	zm.backends[0].lastUsageRefresh = time.Now().Add(-10 * time.Minute)
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) {
+		return nil, zfs.ErrNoZfs
+	}
+	usage := zm.DatasetUsage()
+	assert.Len(t, usage, 1, "previous usage should be retained on error")
+}
+
+func TestDatasetUsageClearsAbsentBackend(t *testing.T) {
+	b := newZfsBackend()
+	b.datasetUsage = map[string]zfsDatasetUsage{"/tank": {used: 1, avail: 1}}
+	b.datasetsFn = optionalPoolSource(func() ([]zfs.Dataset, error) {
+		return nil, zfs.ErrNoZfs
+	})
+
+	datasets, err := b.datasets()
+	require.NoError(t, err, "an absent backend must not produce an error to log")
+	assert.Empty(t, datasets)
+	b.refreshDatasetUsage()
+	assert.Empty(t, b.datasetUsage)
+	assert.False(t, b.lastUsageRefresh.IsZero())
+}
+
+func TestGetDetailForceRefresh(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	poolCalls := 0
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) {
+		poolCalls++
+		return []zfs.PoolStat{{Name: "tank", Alloc: uint64(poolCalls)}}, nil
+	}
+	zm.backends[0].poolStatusesFn = func() ([]zfs.PoolStatus, error) { return nil, nil }
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) { return nil, nil }
+
+	first := zm.GetDetail(false)
+	assert.True(t, first.Complete)
+	require.Len(t, first.Pools, 1)
+	assert.Equal(t, uint64(1), first.Pools[0].Alloc)
+
+	cached := zm.GetDetail(false)
+	require.Len(t, cached.Pools, 1)
+	assert.Equal(t, uint64(1), cached.Pools[0].Alloc)
+	assert.Equal(t, 1, poolCalls)
+
+	refreshed := zm.GetDetail(true)
+	assert.True(t, refreshed.Complete)
+	require.Len(t, refreshed.Pools, 1)
+	assert.Equal(t, uint64(2), refreshed.Pools[0].Alloc)
+	assert.Equal(t, 2, poolCalls)
+}
+
+func TestGetDetailSuccessfulEmptyInventoryClearsCache(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) {
+		return []zfs.PoolStat{{Name: "tank"}}, nil
+	}
+	zm.backends[0].poolStatusesFn = func() ([]zfs.PoolStatus, error) { return nil, nil }
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) { return nil, nil }
+
+	require.Len(t, zm.GetDetail(false).Pools, 1)
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) { return nil, nil }
+	empty := zm.GetDetail(true)
+	assert.True(t, empty.Complete)
+	assert.Empty(t, empty.Pools)
+}
+
+func TestGetDetailFailureReturnsIncompleteCachedInventory(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) {
+		return []zfs.PoolStat{{Name: "tank"}}, nil
+	}
+	zm.backends[0].poolStatusesFn = func() ([]zfs.PoolStatus, error) {
+		return []zfs.PoolStatus{{Name: "tank", Vdevs: []zfs.VdevStatus{{Name: "mirror-0"}}}}, nil
+	}
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) {
+		return []zfs.Dataset{{Name: "tank/data"}}, nil
+	}
+	first := zm.GetDetail(false)
+	require.True(t, first.Complete)
+	require.Len(t, first.Pools[0].Vdevs, 1)
+	require.Len(t, first.Pools[0].Datasets, 1)
+
+	zm.backends[0].poolStatusesFn = func() ([]zfs.PoolStatus, error) { return nil, zfs.ErrNoZfs }
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) { return nil, zfs.ErrNoZfs }
+	partial := zm.GetDetail(true)
+	require.True(t, partial.Complete)
+	require.Len(t, partial.Pools[0].Vdevs, 1)
+	require.Len(t, partial.Pools[0].Datasets, 1)
+
+	zm.backends[0].poolStatsFn = func() ([]zfs.PoolStat, error) { return nil, zfs.ErrNoZfs }
+	lastSuccessfulRefresh := zm.backends[0].lastDetailRefresh
+	failed := zm.GetDetail(true)
+	assert.False(t, failed.Complete)
+	require.Len(t, failed.Pools, 1)
+	assert.Equal(t, "tank", failed.Pools[0].Name)
+	assert.Equal(t, lastSuccessfulRefresh, zm.backends[0].lastDetailRefresh)
+}
+
+func TestZfsMountpoints(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs"}}}
+	zm.backends[0].datasetsFn = func() ([]zfs.Dataset, error) {
+		return []zfs.Dataset{
+			{Name: "tank", Mountpoint: "/tank"},
+			{Name: "rpool/ROOT/pve-1", Mountpoint: "/"},
+		}, nil
+	}
+	mountpoints := zm.ZfsMountpoints()
+	assert.Len(t, mountpoints, 2)
+	assert.True(t, mountpoints["/tank"])
+	assert.True(t, mountpoints["/"])
+}
+
+func TestBtrfsRawCapacityPropagates(t *testing.T) {
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs", poolStatsFn: func() ([]zfs.PoolStat, error) {
+		return []zfs.PoolStat{btrfsPoolStats(btrfs.Filesystem{UUID: "raw", Name: "raw", Size: 200, Alloc: 100, Raw: true})}, nil
+	},
+		poolStatusesFn: func() ([]zfs.PoolStatus, error) { return nil, nil },
+		datasetsFn:     func() ([]zfs.Dataset, error) { return nil, nil }}}}
+	var stats system.Stats
+	zm.Update(&stats)
+	require.True(t, stats.ZfsPools["b:raw"].Raw)
+	detail := zm.GetDetail(true)
+	require.True(t, detail.Complete)
+	require.Len(t, detail.Pools, 1)
+	assert.True(t, detail.Pools[0].Raw)
+}
+
+func TestMarkDuplicatePoolCharts(t *testing.T) {
+	for _, tc := range []struct {
+		name, poolID, device string
+		raw                  bool
+		diskTotal            float64
+		wantUsage, wantIO    bool
+	}{
+		{"single device root", "fs1", "dm-0", false, 100, true, true},
+		{"multi device", "fs1", "", false, 100, true, false},
+		{"different IO device", "fs1", "nvme0n1", false, 100, true, false},
+		{"different filesystem", "fs2", "dm-0", false, 100, false, false},
+		{"unknown identity", "", "dm-0", false, 100, false, false},
+		{"raw usage", "fs1", "dm-0", true, 100, false, true},
+		{"failed disk collection", "fs1", "dm-0", false, 0, false, false},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs", poolData: []zfs.PoolStat{{Name: "arbitrary label", MountID: tc.poolID, IODevice: tc.device, Raw: tc.raw}}}}}
+			stats := &system.Stats{ZfsPools: map[string]*system.ZfsPool{"arbitrary label": {}}}
+			fs := map[string]*system.FsStats{"dm-0": {Root: true, Mountpoint: "/", DiskTotal: tc.diskTotal}}
+			zm.markDuplicateCharts(stats, fs, func(string) string { return "fs1" })
+			assert.Equal(t, tc.wantUsage, stats.ZfsPools["arbitrary label"].HideUsage)
+			assert.Equal(t, tc.wantIO, stats.ZfsPools["arbitrary label"].HideIO)
+			// Bind mounts and custom extra-filesystem names have the same identity.
+			fs["dm-0"].Root = false
+			fs["dm-0"].Mountpoint = "/extra-filesystems/storage"
+			fs["dm-0"].Name = "custom name"
+			stats.ZfsPools["arbitrary label"] = &system.ZfsPool{}
+			zm.markDuplicateCharts(stats, fs, func(string) string { return "fs1" })
+			assert.Equal(t, tc.wantUsage, stats.ZfsPools["arbitrary label"].HideUsage)
+			assert.Equal(t, tc.wantIO, stats.ZfsPools["arbitrary label"].HideIO)
+		})
+	}
+}
+
+func TestBtrfsPoolIdentities(t *testing.T) {
+	old := btrfsFilesystems
+	t.Cleanup(func() { btrfsFilesystems = old })
+	label := "tank"
+	btrfsFilesystems = func() ([]btrfs.Filesystem, error) {
+		return []btrfs.Filesystem{
+			{UUID: "11111111-1111-4111-8111-111111111111", Name: label, Size: 100, Health: "ONLINE", NRead: 100, Devices: []btrfs.Device{{Name: "first"}}},
+			{UUID: "22222222-2222-4222-8222-222222222222", Name: "tank", Size: 200, Health: "DEGRADED", NRead: 200, Devices: []btrfs.Device{{Name: "second"}}},
+		}, nil
+	}
+	zm := &StoragePoolManager{detailInterval: time.Hour, backends: []*poolBackend{{name: "zfs", poolStatsFn: func() ([]zfs.PoolStat, error) { return []zfs.PoolStat{{Name: "tank", Size: 300}}, nil },
+		kernelStatsFn: func() ([]zfs.PoolKernelStat, error) { return []zfs.PoolKernelStat{{Name: "tank", NRead: 300}}, nil },
+		poolStatusesFn: func() ([]zfs.PoolStatus, error) {
+			return []zfs.PoolStatus{{Name: "tank", Vdevs: []zfs.VdevStatus{{Name: "zfs-device"}}}}, nil
+		},
+
+		datasetsFn: func() ([]zfs.Dataset, error) { return []zfs.Dataset{{Name: "tank/data"}}, nil }}, newBtrfsBackend()}}
+	first := "b:11111111-1111-4111-8111-111111111111"
+	second := "b:22222222-2222-4222-8222-222222222222"
+	var stats system.Stats
+	zm.Update(&stats)
+	require.Len(t, stats.ZfsPools, 3)
+	assert.Contains(t, stats.ZfsPools, "tank")
+	assert.Equal(t, "ONLINE", stats.ZfsPools[first].Health)
+	assert.Equal(t, "DEGRADED", stats.ZfsPools[second].Health)
+	assert.Equal(t, uint64(100), zm.backends[1].kernelSamples[first].nread)
+	assert.Equal(t, uint64(200), zm.backends[1].kernelSamples[second].nread)
+	detail := zm.GetDetail(true)
+	require.Len(t, detail.Pools, 3)
+	assert.Equal(t, "zfs-device", detail.Pools[0].Vdevs[0].Name)
+	assert.Len(t, detail.Pools[0].Datasets, 1)
+	assert.Equal(t, "first", detail.Pools[1].Vdevs[0].Name)
+	assert.Empty(t, detail.Pools[1].Datasets)
+	assert.Equal(t, "second", detail.Pools[2].Vdevs[0].Name)
+	label = "renamed"
+	zm.backends[0].lastPoolStats = time.Time{}
+	zm.backends[1].lastPoolStats = time.Time{}
+	zm.Update(&stats)
+	require.Len(t, stats.ZfsPools, 3)
+	assert.Equal(t, "renamed", stats.ZfsPools[first].DisplayName)
+	assert.Equal(t, first, zm.GetDetail(true).Pools[1].Name)
+	assert.Equal(t, "renamed", zm.GetDetail(true).Pools[1].DisplayName)
+}

agent/system.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"errors"
 	"fmt"
+	"io"
 	"log/slog"
 	"os"
 	"runtime"
@@ -11,6 +12,7 @@ import (
 
 	"github.com/henrygd/beszel"
 	"github.com/henrygd/beszel/agent/battery"
+	"github.com/henrygd/beszel/agent/btrfs"
 	"github.com/henrygd/beszel/agent/utils"
 	"github.com/henrygd/beszel/agent/zfs"
 	"github.com/henrygd/beszel/internal/entities/container"
@@ -31,7 +33,11 @@ func (a *Agent) refreshSystemDetails() {
 
 	if a.dockerManager != nil {
 		a.systemDetails.Podman = a.dockerManager.IsPodman()
-		hostInfo, _ = a.dockerManager.GetHostInfo()
+		// Docker's host info describes the machine its daemon runs on. On macOS and
+		// Windows that is a Linux VM, so its CPU and memory totals are not this host's.
+		if runtime.GOOS != "darwin" && runtime.GOOS != "windows" {
+			hostInfo, _ = a.dockerManager.GetHostInfo()
+		}
 	}
 
 	a.systemDetails.Hostname, _ = os.Hostname()
@@ -78,6 +84,12 @@ func (a *Agent) refreshSystemDetails() {
 	if info, err := cpu.Info(); err == nil && len(info) > 0 {
 		a.systemDetails.CpuModel = info[0].ModelName
 	}
+	// gopsutil doesn't parse the "cpu model" field from /proc/cpuinfo, which
+	// is the only source of the CPU model name on MIPS. Fall back to reading
+	// it directly when ModelName is empty.
+	if a.systemDetails.CpuModel == "" {
+		a.systemDetails.CpuModel = getCpuModelFromCpuinfo()
+	}
 	// cores / threads
 	cores, _ := cpu.Counts(false)
 	threads := hostInfo.NCPU
@@ -164,9 +176,9 @@ func (a *Agent) getSystemStats(cacheTimeMs uint16) system.Stats {
 
 	// load average
 	if avgstat, err := load.Avg(); err == nil {
-		systemStats.LoadAvg[0] = avgstat.Load1
+		systemStats.LoadAvg[0] = utils.TwoDecimals(avgstat.Load1)
-		systemStats.LoadAvg[1] = avgstat.Load5
+		systemStats.LoadAvg[1] = utils.TwoDecimals(avgstat.Load5)
-		systemStats.LoadAvg[2] = avgstat.Load15
+		systemStats.LoadAvg[2] = utils.TwoDecimals(avgstat.Load15)
 		slog.Debug("Load average", "5m", avgstat.Load5, "15m", avgstat.Load15)
 	} else {
 		slog.Error("Error getting load average", "err", err)
@@ -208,6 +220,10 @@ func (a *Agent) getSystemStats(cacheTimeMs uint16) system.Stats {
 	// disk i/o (cache-aware per interval)
 	a.updateDiskIo(cacheTimeMs, &systemStats)
 
+	// storage pool stats
+	a.storagePoolManager.Update(&systemStats)
+	a.storagePoolManager.markDuplicateCharts(&systemStats, a.fsStats, btrfs.MountID)
+
 	// network stats (per cache interval)
 	a.updateNetworkStats(cacheTimeMs, &systemStats)
 
@@ -258,13 +274,66 @@ func (a *Agent) getSystemStats(cacheTimeMs uint16) system.Stats {
 	a.systemInfo.MemPct = systemStats.MemPct
 	a.systemInfo.DiskPct = systemStats.DiskPct
 	a.systemInfo.Battery = systemStats.Battery
-	a.systemInfo.Uptime, _ = host.Uptime()
+	a.systemInfo.Uptime, _ = getUptime()
 	a.systemInfo.BandwidthBytes = systemStats.Bandwidth[0] + systemStats.Bandwidth[1]
 	a.systemInfo.Threads = a.systemDetails.Threads
 
 	return systemStats
 }
 
+// cpuModelFallbackKeys are the field names to look for in /proc/cpuinfo when
+// gopsutil fails to return a ModelName. The "cpu model" key is used on MIPS
+// (e.g. "MIPS 1004Kc V2.15"), while "system type" provides SoC information
+// on various embedded architectures.
+var cpuModelFallbackKeys = []string{"cpu model", "system type"}
+
+// getCpuModelFromCpuinfo reads /proc/cpuinfo and returns a CPU model string.
+// This is a fallback for architectures where gopsutil's cpu.Info() does not
+// populate ModelName, most notably MIPS.
+func getCpuModelFromCpuinfo() string {
+	file, err := os.Open("/proc/cpuinfo")
+	if err != nil {
+		return ""
+	}
+	defer file.Close()
+	return parseCpuModel(file)
+}
+
+// parseCpuModel scans r (expected to be /proc/cpuinfo content) and returns
+// a combined CPU model string. It collects values from all matching keys
+// and joins them with " / " when multiple are found.
+func parseCpuModel(r io.Reader) string {
+	lines := readLines(r)
+	var parts []string
+	for _, key := range cpuModelFallbackKeys {
+		for _, line := range lines {
+			after, found := strings.CutPrefix(line, key)
+			if !found {
+				continue
+			}
+			after = strings.TrimSpace(after)
+			if len(after) < 2 || after[0] != ':' {
+				continue
+			}
+			if value := strings.TrimSpace(after[1:]); value != "" {
+				parts = append(parts, value)
+				break
+			}
+		}
+	}
+	return strings.Join(parts, " / ")
+}
+
+// readLines reads all lines from r into a slice.
+func readLines(r io.Reader) []string {
+	scanner := bufio.NewScanner(r)
+	var lines []string
+	for scanner.Scan() {
+		lines = append(lines, scanner.Text())
+	}
+	return lines
+}
+
 // calculateHostMemoryUsage derives counters defensively because /proc/meminfo may
 // change while gopsutil reads it. Invalid unsigned subtractions saturate at zero.
 func calculateHostMemoryUsage(v *mem.VirtualMemoryStat, htop bool) (used, cacheBuff, swapUsed uint64) {
@@ -283,7 +352,8 @@ func calculateHostMemoryUsage(v *mem.VirtualMemoryStat, htop bool) (used, cacheB
 	if htop {
 		used = saturatingSub(v.Total, v.Free, cacheBuff)
 	}
-	return used, cacheBuff, saturatingSub(v.SwapTotal, v.SwapFree, v.SwapCached)
+	// Cached swap pages still occupy swap slots and are included in `free`'s used value.
+	return used, cacheBuff, saturatingSub(v.SwapTotal, v.SwapFree)
 }
 
 // saturatingSub subtracts each value, returning zero on underflow.

agent/system_test.go

@@ -1,6 +1,7 @@
 package agent
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/henrygd/beszel/internal/common"
@@ -46,14 +47,14 @@ func TestCalculateHostMemoryUsage(t *testing.T) {
 			memory:    mem.VirtualMemoryStat{Total: 100, Available: 40, Used: 60, Free: 20, Cached: 25, Buffers: 10, Shared: 5, SwapTotal: 20, SwapFree: 8, SwapCached: 2},
 			used:      60,
 			cacheBuff: 30,
-			swapUsed:  10,
+			swapUsed:  12,
 		},
 		{
 			name:      "inconsistent counters saturate",
 			memory:    mem.VirtualMemoryStat{Total: 100, Available: 110, Used: ^uint64(0) - 9, Free: 90, Cached: 5, Buffers: 10, Shared: 20, SwapTotal: 10, SwapFree: 9, SwapCached: 2},
 			used:      0,
 			cacheBuff: 0,
-			swapUsed:  0,
+			swapUsed:  1,
 		},
 		{
 			name:      "htop subtraction saturates",
@@ -61,7 +62,7 @@ func TestCalculateHostMemoryUsage(t *testing.T) {
 			htop:      true,
 			used:      0,
 			cacheBuff: 25,
-			swapUsed:  15,
+			swapUsed:  20,
 		},
 		{
 			name:      "zero cache from shared cancellation does not fall back",
@@ -113,3 +114,81 @@ func TestUpdateSystemDetailsMarksDetailsDirty(t *testing.T) {
 	assert.False(t, agent.detailsDirty)
 	assert.Nil(t, original.Details)
 }
+
+func TestParseCpuModel(t *testing.T) {
+	tests := []struct {
+		name     string
+		input    string
+		expected string
+	}{
+		{
+			name: "MIPS with both cpu model and system type",
+			input: `system type             : MediaTek MT7621 ver:1 eco:3
+machine                 : ASUS RT-AX53U
+processor               : 0
+cpu model               : MIPS 1004Kc V2.15
+BogoMIPS                : 586.13
+wait instruction        : yes`,
+			expected: "MIPS 1004Kc V2.15 / MediaTek MT7621 ver:1 eco:3",
+		},
+		{
+			name: "MIPS with different SoC",
+			input: `system type             : Atheros AR7161 rev 2
+machine                 : NETGEAR WNDR3700
+processor               : 0
+cpu model               : MIPS 24Kc V7.4
+BogoMIPS                : 452.19`,
+			expected: "MIPS 24Kc V7.4 / Atheros AR7161 rev 2",
+		},
+		{
+			name: "only system type when cpu model missing",
+			input: `system type             : Broadcom BCM47xx
+processor               : 0
+BogoMIPS                : 296.11`,
+			expected: "Broadcom BCM47xx",
+		},
+		{
+			name: "only cpu model when system type missing",
+			input: `processor               : 0
+cpu model               : MIPS 34Kc V2.15
+BogoMIPS                : 300.00`,
+			expected: "MIPS 34Kc V2.15",
+		},
+		{
+			name: "x86 cpuinfo returns empty",
+			input: `processor	: 0
+vendor_id	: GenuineIntel
+cpu family	: 6
+model		: 142
+model name	: Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz
+stepping	: 10`,
+			expected: "",
+		},
+		{
+			name:     "empty input",
+			input:    "",
+			expected: "",
+		},
+		{
+			name: "cpu model with extra whitespace",
+			input: `processor               : 0
+cpu model               :   MIPS 34Kc V2.15
+BogoMIPS                : 300.00`,
+			expected: "MIPS 34Kc V2.15",
+		},
+		{
+			name: "cpu model without value",
+			input: `processor               : 0
+cpu model               :
+BogoMIPS                : 300.00`,
+			expected: "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := parseCpuModel(strings.NewReader(tt.input))
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}

agent/test-data/zfs/zfs_list.txt

@@ -0,0 +1,9 @@
+tank	12000000000000	11999000000000	/tank
+tank/apps	1000000000000	11999000000000	/tank/apps
+tank/backup	2000000000000	11999000000000	/tank/backup
+tank/media	1000000000000	11999000000000	/tank/my media
+rpool	900000000000	300000000000	-
+rpool/ROOT	1000000000	300000000000	-
+rpool/ROOT/pve-1	890000000000	300000000000	/
+rpool/data	9000000000	300000000000	-
+rpool/data/subvol-100-disk-0	400000000000	300000000000	/subvol-100-disk-0

agent/test-data/zfs/zpool_list.txt

@@ -0,0 +1,2 @@
+tank	23999000000000	12000000000000	11999000000000	ONLINE
+rpool	1200000000000	900000000000	300000000000	DEGRADED

agent/test-data/zfs/zpool_status.txt

@@ -0,0 +1,29 @@
+  pool: tank
+ state: ONLINE
+  scan: scrub repaired 0B in 00:05:12 with 0 errors on Sun Jun  1 02:00:12 2025
+config:
+
+	NAME        STATE     READ WRITE CKSUM
+	tank        ONLINE       0     0     0
+	  mirror-0  ONLINE       0     0     0
+	    sda     ONLINE       0     0     0
+	    sdb     ONLINE       0     0     0
+
+errors: No known data errors
+
+  pool: rpool
+ state: DEGRADED
+ status: One or more devices could not be used because the label is missing or
+	invalid.  Sufficient replicas exist for the pool to continue functioning in a
+	degraded state.
+  scan: scrub in progress since Sun Jun  8 01:00:00 2025
+	10.00% done, 01:30:00 to go, 0.00/s
+config:
+
+	NAME        STATE     READ WRITE CKSUM
+	rpool       DEGRADED     0     0     0
+	  mirror-0  DEGRADED     0     0     0
+	    sda     ONLINE       0     0     0
+	    sdb     FAULTED      1     2     3
+
+errors: 1 data errors, use '-v' for a list

agent/uptime_linux.go

@@ -0,0 +1,44 @@
+//go:build linux
+
+package agent
+
+import (
+	"math"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/shirou/gopsutil/v4/host"
+)
+
+// uptimeFilePath is a variable so tests can point it at a fixture.
+var uptimeFilePath = "/proc/uptime"
+
+// getUptime returns the system uptime in seconds.
+//
+// This reads /proc/uptime instead of using host.Uptime(), which calls the
+// sysinfo(2) syscall. Inside an LXC container lxcfs virtualizes /proc/uptime
+// but cannot intercept a syscall, so sysinfo(2) reports the host's uptime
+// rather than the container's.
+//
+// Falls back to host.Uptime() if /proc/uptime is missing or unparseable, so
+// behavior is unchanged anywhere the file isn't available.
+func getUptime() (uint64, error) {
+	data, err := os.ReadFile(uptimeFilePath)
+	if err != nil {
+		return host.Uptime()
+	}
+	fields := strings.Fields(string(data))
+	if len(fields) == 0 {
+		return host.Uptime()
+	}
+	seconds, err := strconv.ParseFloat(fields[0], 64)
+	if err != nil ||
+		math.IsNaN(seconds) ||
+		math.IsInf(seconds, 0) ||
+		seconds < 0 ||
+		seconds >= 1<<64 {
+		return host.Uptime()
+	}
+	return uint64(seconds), nil
+}

agent/uptime_linux_test.go

@@ -0,0 +1,101 @@
+//go:build linux
+
+package agent
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestGetUptimeFromProc(t *testing.T) {
+	tests := []struct {
+		name     string
+		contents string
+		want     uint64
+	}{
+		{"typical", "12345.67 98765.43\n", 12345},
+		{"zero", "0.00 0.00\n", 0},
+		{"no trailing newline", "42.99 7.00", 42},
+		{"single field", "600.5", 600},
+		{"large value", "266030.12 1000000.00\n", 266030},
+	}
+
+	prev := uptimeFilePath
+	t.Cleanup(func() { uptimeFilePath = prev })
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			path := filepath.Join(t.TempDir(), "uptime")
+			if err := os.WriteFile(path, []byte(tt.contents), 0o644); err != nil {
+				t.Fatal(err)
+			}
+			uptimeFilePath = path
+
+			got, err := getUptime()
+			if err != nil {
+				t.Fatalf("getUptime() returned error: %v", err)
+			}
+			if got != tt.want {
+				t.Errorf("getUptime() = %d, want %d", got, tt.want)
+			}
+		})
+	}
+}
+
+func writeUptime(contents string) func(t *testing.T) string {
+	return func(t *testing.T) string {
+		path := filepath.Join(t.TempDir(), "uptime")
+		if err := os.WriteFile(path, []byte(contents), 0o644); err != nil {
+			t.Fatal(err)
+		}
+		return path
+	}
+}
+
+// Malformed, missing, or out-of-range input must fall back to host.Uptime()
+// rather than returning a bogus value, so the agent still reports something sane.
+func TestGetUptimeFallsBack(t *testing.T) {
+	prev := uptimeFilePath
+	t.Cleanup(func() { uptimeFilePath = prev })
+
+	for _, tt := range []struct {
+		name    string
+		prepare func(t *testing.T) string
+	}{
+		{"missing file", func(t *testing.T) string {
+			return filepath.Join(t.TempDir(), "does-not-exist")
+		}},
+		{"empty file", func(t *testing.T) string {
+			path := filepath.Join(t.TempDir(), "uptime")
+			if err := os.WriteFile(path, nil, 0o644); err != nil {
+				t.Fatal(err)
+			}
+			return path
+		}},
+		{"unparseable", func(t *testing.T) string {
+			path := filepath.Join(t.TempDir(), "uptime")
+			if err := os.WriteFile(path, []byte("not-a-number 1.0\n"), 0o644); err != nil {
+				t.Fatal(err)
+			}
+			return path
+		}},
+		{"NaN", writeUptime("NaN 1.0\n")},
+		{"positive infinity", writeUptime("+Inf 1.0\n")},
+		{"negative infinity", writeUptime("-Inf 1.0\n")},
+		{"negative", writeUptime("-42.5 1.0\n")},
+		{"exceeds uint64 range", writeUptime("1e20 1.0\n")},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			uptimeFilePath = tt.prepare(t)
+
+			got, err := getUptime()
+			if err != nil {
+				t.Fatalf("getUptime() returned error: %v", err)
+			}
+			if got == 0 {
+				t.Error("getUptime() = 0, expected fallback to host.Uptime()")
+			}
+		})
+	}
+}

agent/uptime_stub.go

@@ -0,0 +1,10 @@
+//go:build !linux
+
+package agent
+
+import "github.com/shirou/gopsutil/v4/host"
+
+// getUptime returns the system uptime in seconds.
+func getUptime() (uint64, error) {
+	return host.Uptime()
+}

agent/zfs/zfs.go

@@ -0,0 +1,170 @@
+// Package zfs provides functions to read ZFS statistics.
+package zfs
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+	"time"
+)
+
+var commandTimeout = 10 * time.Second
+
+var commandOutput = func(name string, args ...string) ([]byte, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), commandTimeout)
+	defer cancel()
+	cmd := exec.CommandContext(ctx, name, args...)
+	cmd.Env = append(os.Environ(), "LC_ALL=C", "LANG=C")
+	out, err := cmd.Output()
+	if ctx.Err() != nil {
+		return nil, fmt.Errorf("%s timed out after %s: %w", name, commandTimeout, ctx.Err())
+	}
+	return out, err
+}
+
+// ErrNoZfs is returned when the ZFS utilities or kernel interfaces are unavailable.
+var ErrNoZfs = errors.New("zfs utilities unavailable")
+
+// PoolStat is a snapshot of a ZFS pool's capacity and health.
+type PoolStat struct {
+	DisplayName string // optional friendly name; Name remains the stable key
+	MountID     string // Btrfs filesystem identity, empty for other backends
+	IODevice    string // sole Btrfs member device, if known
+	Raw         bool   // physical accounting rather than usable filesystem space
+	Name        string
+	Size        uint64 // total capacity in bytes
+	Alloc       uint64 // allocated bytes
+	Free        uint64 // free bytes
+	Health      string // ONLINE, DEGRADED, FAULTED, ...
+}
+
+// PoolKernelStat is the inexpensive pool telemetry exposed by the ZFS kernel.
+// NRead and NWrite are cumulative byte counters since the pool was imported.
+type PoolKernelStat struct {
+	Name   string
+	Health string
+	NRead  uint64
+	NWrite uint64
+}
+
+// PoolIoStats holds calculated per-second I/O rates for a pool.
+type PoolIoStats struct {
+	NRead  uint64
+	NWrite uint64
+}
+
+// Dataset is a single ZFS dataset with usage information.
+type Dataset struct {
+	Name       string
+	Used       uint64
+	Avail      uint64
+	Mountpoint string
+}
+
+// PoolStats returns capacity and health for all pools on the system using
+// `zpool list`. Frequent health and I/O sampling uses PoolKernelStats instead.
+func PoolStats() ([]PoolStat, error) {
+	if err := checkZfsDevice(); err != nil {
+		return nil, err
+	}
+	out, err := commandOutput("zpool", "list", "-Hp", "-o", "name,size,alloc,free,health")
+	if err != nil {
+		var exitErr *exec.ExitError
+		if errors.As(err, &exitErr) && strings.Contains(string(exitErr.Stderr), "no pools available") {
+			return nil, nil
+		}
+		return nil, fmt.Errorf("zpool list: %w", err)
+	}
+	return parseZpoolListOutput(out)
+}
+
+// Datasets returns all datasets on the system with usage and mountpoint
+// information using `zfs list` (recursive by default).
+func Datasets() ([]Dataset, error) {
+	if err := checkZfsDevice(); err != nil {
+		return nil, err
+	}
+	out, err := commandOutput("zfs", "list", "-Hp", "-o", "name,used,avail,mountpoint")
+	if err != nil {
+		return nil, fmt.Errorf("zfs list: %w", err)
+	}
+	return parseZfsListOutput(out)
+}
+
+// parseZpoolListOutput parses `zpool list -Hp -o name,size,alloc,free,health` output.
+// Columns are tab-separated; numeric columns are raw bytes.
+func parseZpoolListOutput(out []byte) ([]PoolStat, error) {
+	var pools []PoolStat
+	scanner := bufio.NewScanner(bytes.NewReader(out))
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" {
+			continue
+		}
+		if line == "no pools available" && len(pools) == 0 {
+			return nil, nil
+		}
+		fields := strings.Split(line, "\t")
+		if len(fields) < 5 {
+			return nil, fmt.Errorf("unexpected zpool list line: %q", line)
+		}
+		size, err := strconv.ParseUint(fields[1], 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("parsing size for pool %q: %w", fields[0], err)
+		}
+		alloc, err := strconv.ParseUint(fields[2], 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("parsing alloc for pool %q: %w", fields[0], err)
+		}
+		free, err := strconv.ParseUint(fields[3], 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("parsing free for pool %q: %w", fields[0], err)
+		}
+		pools = append(pools, PoolStat{
+			Name:   fields[0],
+			Size:   size,
+			Alloc:  alloc,
+			Free:   free,
+			Health: fields[4],
+		})
+	}
+	return pools, scanner.Err()
+}
+
+// parseZfsListOutput parses `zfs list -Hp -o name,used,avail,mountpoint` output.
+// The mountpoint column may contain spaces, so it is split on tabs only.
+func parseZfsListOutput(out []byte) ([]Dataset, error) {
+	var datasets []Dataset
+	scanner := bufio.NewScanner(bytes.NewReader(out))
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" {
+			continue
+		}
+		fields := strings.SplitN(line, "\t", 4)
+		if len(fields) < 4 {
+			return nil, fmt.Errorf("unexpected zfs list line: %q", line)
+		}
+		used, err := strconv.ParseUint(fields[1], 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("parsing used for dataset %q: %w", fields[0], err)
+		}
+		avail, err := strconv.ParseUint(fields[2], 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("parsing avail for dataset %q: %w", fields[0], err)
+		}
+		datasets = append(datasets, Dataset{
+			Name:       fields[0],
+			Used:       used,
+			Avail:      avail,
+			Mountpoint: fields[3],
+		})
+	}
+	return datasets, scanner.Err()
+}

agent/zfs/zfs_freebsd.go

@@ -3,9 +3,17 @@
 package zfs
 
 import (
+	"errors"
+
 	"golang.org/x/sys/unix"
 )
 
 func ARCSize() (uint64, error) {
 	return unix.SysctlUint64("kstat.zfs.misc.arcstats.size")
 }
+
+// FreeBSD does not expose Linux's per-pool procfs kstats. Capacity, health,
+// and detail collection still work through the cached utilities.
+func PoolKernelStats() ([]PoolKernelStat, error) {
+	return nil, errors.ErrUnsupported
+}

agent/zfs/zfs_linux.go

@@ -5,14 +5,21 @@ package zfs
 
 import (
 	"bufio"
+	"errors"
 	"fmt"
 	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 )
 
+var (
+	procZfsPath = "/proc/spl/kstat/zfs"
+	devZfsPath  = "/dev/zfs"
+)
+
 func ARCSize() (uint64, error) {
-	file, err := os.Open("/proc/spl/kstat/zfs/arcstats")
+	file, err := os.Open(filepath.Join(procZfsPath, "arcstats"))
 	if err != nil {
 		return 0, err
 	}
@@ -29,6 +36,180 @@ func ARCSize() (uint64, error) {
 			return strconv.ParseUint(fields[2], 10, 64)
 		}
 	}
+	if err := scanner.Err(); err != nil {
+		return 0, err
+	}
 
 	return 0, fmt.Errorf("size field not found in arcstats")
 }
+
+// checkZfsDevice lets containers without /dev/zfs fail fast instead of
+// waiting for ZFS utility commands to time out.
+func checkZfsDevice() error {
+	_, err := os.Stat(devZfsPath)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return ErrNoZfs
+		}
+		return err
+	}
+	return nil
+}
+
+// PoolKernelStats reads pool state and cumulative I/O counters directly from
+// procfs. These kstats are the same interfaces used by node_exporter's Linux
+// ZFS collector and avoid keeping a `zpool iostat` subprocess alive.
+func PoolKernelStats() ([]PoolKernelStat, error) {
+	poolDirs := make(map[string]struct{})
+	for _, filename := range []string{"state", "io", "objset-*"} {
+		paths, err := filepath.Glob(filepath.Join(procZfsPath, "*", filename))
+		if err != nil {
+			return nil, err
+		}
+		for _, path := range paths {
+			poolDirs[filepath.Dir(path)] = struct{}{}
+		}
+	}
+	if len(poolDirs) == 0 {
+		return nil, ErrNoZfs
+	}
+	pools := make([]PoolKernelStat, 0, len(poolDirs))
+	for poolDir := range poolDirs {
+		nread, nwrite, err := readPoolCounters(poolDir)
+		if err != nil {
+			if errors.Is(err, os.ErrNotExist) {
+				continue // pool may have been exported after the glob
+			}
+			return nil, err
+		}
+		state, err := os.ReadFile(filepath.Join(poolDir, "state"))
+		if err != nil && !errors.Is(err, os.ErrNotExist) {
+			return nil, err
+		}
+		pools = append(pools, PoolKernelStat{
+			Name: filepath.Base(poolDir), Health: strings.ToUpper(strings.TrimSpace(string(state))),
+			NRead: nread, NWrite: nwrite,
+		})
+	}
+	if len(pools) == 0 {
+		return nil, ErrNoZfs
+	}
+	return pools, nil
+}
+
+// readPoolCounters supports both ZFS kernel interfaces. OpenZFS through 2.3
+// exposes aggregate vdev counters in "io". When that file is unavailable, sum
+// the logical I/O counters exposed for each dataset in the pool.
+func readPoolCounters(poolDir string) (uint64, uint64, error) {
+	nread, nwrite, err := readPoolIO(filepath.Join(poolDir, "io"))
+	if err == nil || !errors.Is(err, os.ErrNotExist) {
+		return nread, nwrite, err
+	}
+	return readPoolObjsets(poolDir)
+}
+
+func readPoolIO(path string) (uint64, uint64, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return 0, 0, err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) < 2 || fields[0] != "nread" {
+			continue
+		}
+		if !scanner.Scan() {
+			break
+		}
+		values := strings.Fields(scanner.Text())
+		if len(values) < 2 {
+			break
+		}
+		nread, err := strconv.ParseUint(values[0], 10, 64)
+		if err != nil {
+			return 0, 0, fmt.Errorf("parsing nread in %s: %w", path, err)
+		}
+		nwrite, err := strconv.ParseUint(values[1], 10, 64)
+		if err != nil {
+			return 0, 0, fmt.Errorf("parsing nwritten in %s: %w", path, err)
+		}
+		return nread, nwrite, nil
+	}
+	if err := scanner.Err(); err != nil {
+		return 0, 0, err
+	}
+	return 0, 0, fmt.Errorf("I/O counters not found in %s", path)
+}
+
+func readPoolObjsets(poolDir string) (uint64, uint64, error) {
+	paths, err := filepath.Glob(filepath.Join(poolDir, "objset-*"))
+	if err != nil {
+		return 0, 0, err
+	}
+	if len(paths) == 0 {
+		return 0, 0, fmt.Errorf("dataset I/O counters not found in %s", poolDir)
+	}
+
+	var totalRead, totalWrite uint64
+	objsetsRead := 0
+	for _, path := range paths {
+		nread, nwrite, err := readObjsetIO(path)
+		if errors.Is(err, os.ErrNotExist) {
+			continue // dataset may have been destroyed after the glob
+		}
+		if err != nil {
+			return 0, 0, err
+		}
+		totalRead += nread
+		totalWrite += nwrite
+		objsetsRead++
+	}
+	if objsetsRead == 0 {
+		return 0, 0, fmt.Errorf("dataset I/O counters not found in %s", poolDir)
+	}
+	return totalRead, totalWrite, nil
+}
+
+func readObjsetIO(path string) (uint64, uint64, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return 0, 0, err
+	}
+	defer file.Close()
+
+	var nread, nwrite uint64
+	var foundRead, foundWrite bool
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		fields := strings.Fields(scanner.Text())
+		if len(fields) < 3 {
+			continue
+		}
+		var target *uint64
+		switch fields[0] {
+		case "nread":
+			target = &nread
+			foundRead = true
+		case "nwritten":
+			target = &nwrite
+			foundWrite = true
+		default:
+			continue
+		}
+		value, err := strconv.ParseUint(fields[2], 10, 64)
+		if err != nil {
+			return 0, 0, fmt.Errorf("parsing %s in %s: %w", fields[0], path, err)
+		}
+		*target = value
+	}
+	if err := scanner.Err(); err != nil {
+		return 0, 0, err
+	}
+	if !foundRead || !foundWrite {
+		return 0, 0, fmt.Errorf("incomplete I/O counters in %s", path)
+	}
+	return nread, nwrite, nil
+}

agent/zfs/zfs_linux_test.go

@@ -0,0 +1,153 @@
+//go:build testing && linux
+
+package zfs
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPoolKernelStats(t *testing.T) {
+	root := t.TempDir()
+	oldPath := procZfsPath
+	procZfsPath = root
+	t.Cleanup(func() { procZfsPath = oldPath })
+
+	poolDir := filepath.Join(root, "tank")
+	require.NoError(t, os.MkdirAll(poolDir, 0o755))
+	require.NoError(t, os.WriteFile(filepath.Join(poolDir, "io"), []byte(
+		"11 3 0x00 1 80 0 0\n"+
+			"nread nwritten reads writes wtime wlentime wupdate rtime rlentime rupdate wcnt rcnt\n"+
+			"1884160 6450688 22 978 0 0 0 0 0 0 0 0\n",
+	), 0o644))
+	require.NoError(t, os.WriteFile(filepath.Join(poolDir, "state"), []byte("DEGRADED\n"), 0o644))
+
+	stats, err := PoolKernelStats()
+	require.NoError(t, err)
+	require.Len(t, stats, 1)
+	assert.Equal(t, PoolKernelStat{
+		Name: "tank", Health: "DEGRADED", NRead: 1884160, NWrite: 6450688,
+	}, stats[0])
+}
+
+func TestPoolKernelStatsOpenZfs24(t *testing.T) {
+	root := t.TempDir()
+	oldPath := procZfsPath
+	procZfsPath = root
+	t.Cleanup(func() { procZfsPath = oldPath })
+
+	poolDir := filepath.Join(root, "tank")
+	require.NoError(t, os.MkdirAll(poolDir, 0o755))
+	require.NoError(t, os.WriteFile(filepath.Join(poolDir, "state"), []byte("ONLINE\n"), 0o644))
+	require.NoError(t, os.WriteFile(filepath.Join(poolDir, "objset-0x1"), []byte(
+		"34 1 0x01 28 7872 0 0\n"+
+			"name type data\n"+
+			"dataset_name 7 tank\n"+
+			"nwritten 4 2000\n"+
+			"nread 4 1000\n",
+	), 0o644))
+	require.NoError(t, os.WriteFile(filepath.Join(poolDir, "objset-0x2"), []byte(
+		"34 1 0x01 28 7872 0 0\n"+
+			"name type data\n"+
+			"dataset_name 7 tank/videos\n"+
+			"nwritten 4 400\n"+
+			"nread 4 300\n",
+	), 0o644))
+
+	stats, err := PoolKernelStats()
+	require.NoError(t, err)
+	require.Len(t, stats, 1)
+	assert.Equal(t, PoolKernelStat{
+		Name: "tank", Health: "ONLINE", NRead: 1300, NWrite: 2400,
+	}, stats[0])
+}
+
+func TestPoolKernelStatsNoZfs(t *testing.T) {
+	oldPath := procZfsPath
+	procZfsPath = t.TempDir()
+	t.Cleanup(func() { procZfsPath = oldPath })
+
+	_, err := PoolKernelStats()
+	assert.ErrorIs(t, err, ErrNoZfs)
+}
+
+func TestReadPoolIORejectsMalformedCounters(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "io")
+	require.NoError(t, os.WriteFile(path, []byte("nread nwritten\nnope 10\n"), 0o644))
+	_, _, err := readPoolIO(path)
+	require.Error(t, err)
+}
+
+func TestReadObjsetIORequiresAllCounters(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "objset-0x1")
+	require.NoError(t, os.WriteFile(path, []byte("nread 4 10\n"), 0o644))
+	_, _, err := readObjsetIO(path)
+	require.Error(t, err)
+}
+
+func TestCollectorsSkipCommandsWhenDevZfsMissing(t *testing.T) {
+	root := t.TempDir()
+	oldDevZfsPath := devZfsPath
+	devZfsPath = filepath.Join(root, "missing")
+	t.Cleanup(func() { devZfsPath = oldDevZfsPath })
+
+	oldCommandOutput := commandOutput
+	commandOutput = func(name string, args ...string) ([]byte, error) {
+		t.Fatalf("unexpected %s call with %v", name, args)
+		return nil, nil
+	}
+	t.Cleanup(func() { commandOutput = oldCommandOutput })
+
+	_, err := PoolStats()
+	assert.ErrorIs(t, err, ErrNoZfs)
+	_, err = Datasets()
+	assert.ErrorIs(t, err, ErrNoZfs)
+}
+
+func TestDatasetsDelegatesWhenDevZfsPresent(t *testing.T) {
+	oldDevZfsPath := devZfsPath
+	devZfsPath = filepath.Join(t.TempDir(), "zfs")
+	require.NoError(t, os.WriteFile(devZfsPath, nil, 0o644))
+	t.Cleanup(func() { devZfsPath = oldDevZfsPath })
+
+	oldCommandOutput := commandOutput
+	commandOutput = func(name string, args ...string) ([]byte, error) {
+		assert.Equal(t, "zfs", name)
+		assert.Equal(t, []string{"list", "-Hp", "-o", "name,used,avail,mountpoint"}, args)
+		return []byte("tank\t50\t50\t/tank\n"), nil
+	}
+	t.Cleanup(func() { commandOutput = oldCommandOutput })
+
+	datasets, err := Datasets()
+	require.NoError(t, err)
+	assert.Equal(t, []Dataset{{Name: "tank", Used: 50, Avail: 50, Mountpoint: "/tank"}}, datasets)
+}
+
+func TestPoolStatsDelegatesToZpoolWhenDevZfsPresent(t *testing.T) {
+	root := t.TempDir()
+	devFile := filepath.Join(root, "zfs")
+	require.NoError(t, os.WriteFile(devFile, []byte(""), 0o644))
+
+	oldDevZfsPath := devZfsPath
+	devZfsPath = devFile
+	t.Cleanup(func() { devZfsPath = oldDevZfsPath })
+
+	oldCommandOutput := commandOutput
+	called := false
+	commandOutput = func(name string, args ...string) ([]byte, error) {
+		called = true
+		assert.Equal(t, "zpool", name)
+		assert.Equal(t, []string{"list", "-Hp", "-o", "name,size,alloc,free,health"}, args)
+		return []byte("tank\t100\t50\t50\tONLINE\n"), nil
+	}
+	t.Cleanup(func() { commandOutput = oldCommandOutput })
+
+	pools, err := PoolStats()
+	require.NoError(t, err)
+	assert.True(t, called)
+	assert.Equal(t, []PoolStat{{Name: "tank", Size: 100, Alloc: 50, Free: 50, Health: "ONLINE"}}, pools)
+}

agent/zfs/zfs_nonlinux.go

@@ -0,0 +1,9 @@
+//go:build !linux
+
+package zfs
+
+// The /dev/zfs probe is Linux-specific. Other platforms detect availability
+// through the ZFS utilities themselves.
+func checkZfsDevice() error {
+	return nil
+}

agent/zfs/zfs_nonlinux_test.go

@@ -0,0 +1,33 @@
+//go:build testing && !linux
+
+package zfs
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCollectorsUseUtilitiesOnNonLinux(t *testing.T) {
+	oldCommandOutput := commandOutput
+	commandOutput = func(name string, args ...string) ([]byte, error) {
+		switch name {
+		case "zpool":
+			return []byte("tank\t100\t50\t50\tONLINE\n"), nil
+		case "zfs":
+			return []byte("tank\t50\t50\t/tank\n"), nil
+		default:
+			t.Fatalf("unexpected command %s", name)
+			return nil, nil
+		}
+	}
+	t.Cleanup(func() { commandOutput = oldCommandOutput })
+
+	pools, err := PoolStats()
+	require.NoError(t, err)
+	assert.Equal(t, []PoolStat{{Name: "tank", Size: 100, Alloc: 50, Free: 50, Health: "ONLINE"}}, pools)
+	datasets, err := Datasets()
+	require.NoError(t, err)
+	assert.Equal(t, []Dataset{{Name: "tank", Used: 50, Avail: 50, Mountpoint: "/tank"}}, datasets)
+}

agent/zfs/zfs_status.go

@@ -0,0 +1,150 @@
+package zfs
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// PoolStatus holds parsed `zpool status` information for one pool.
+type PoolStatus struct {
+	Name  string
+	State string // ONLINE, DEGRADED, FAULTED, ...
+	Scrub ScrubStatus
+	Vdevs []VdevStatus
+}
+
+// ScrubStatus holds the scrub (or resilver) status parsed from the scan line.
+type ScrubStatus struct {
+	State    string // NONE, SCANNING, FINISHED, CANCELED
+	Progress string // e.g. "10.00%" while scanning
+	Errors   uint64
+}
+
+// VdevStatus is a single vdev row (mirror, raidz, or leaf disk).
+type VdevStatus struct {
+	Name         string
+	State        string
+	ReadErrs     uint64
+	WriteErrs    uint64
+	ChecksumErrs uint64
+}
+
+var (
+	progressRe = regexp.MustCompile(`(\d+\.\d+)%\s+done`)
+	errorsRe   = regexp.MustCompile(`with\s+(\d+)\s+errors`)
+)
+
+// PoolStatuses runs `zpool status` and parses per-pool state, scrub, and vdev
+// information. The human-readable format has been stable across OpenZFS
+// releases; rows are matched by their tabular shape rather than position.
+func PoolStatuses() ([]PoolStatus, error) {
+	out, err := commandOutput("zpool", "status")
+	if err != nil {
+		return nil, fmt.Errorf("zpool status: %w", err)
+	}
+	return parseZpoolStatusOutput(out)
+}
+
+// parseZpoolStatusOutput parses the output of `zpool status`.
+func parseZpoolStatusOutput(out []byte) ([]PoolStatus, error) {
+	var pools []PoolStatus
+	var current *PoolStatus
+	inConfig := false
+	scanContinuation := false // next non-blank line continues the scan line (progress)
+
+	scanner := bufio.NewScanner(bytes.NewReader(out))
+	for scanner.Scan() {
+		line := scanner.Text()
+		trimmed := strings.TrimSpace(line)
+
+		switch {
+		case strings.HasPrefix(trimmed, "pool:"):
+			pools = append(pools, PoolStatus{Name: strings.TrimSpace(strings.TrimPrefix(trimmed, "pool:"))})
+			current = &pools[len(pools)-1]
+			inConfig = false
+			scanContinuation = false
+		case current == nil:
+			continue
+		case strings.HasPrefix(trimmed, "state:"):
+			current.State = strings.TrimSpace(strings.TrimPrefix(trimmed, "state:"))
+		case strings.HasPrefix(trimmed, "scan:"):
+			current.Scrub = parseScanLine(trimmed)
+			// zpool status prints the progress percentage on the line after scan.
+			scanContinuation = true
+		case trimmed == "config:":
+			inConfig = true
+		case scanContinuation:
+			// The line after scan: may be an indented progress continuation.
+			if m := progressRe.FindStringSubmatch(trimmed); m != nil {
+				current.Scrub.Progress = m[1] + "%"
+			}
+			scanContinuation = false
+		case inConfig && (line == "" || strings.HasPrefix(line, " ") || strings.HasPrefix(line, "\t")):
+			// Table rows are indented; blank lines separate sections. The
+			// column header and the pool's own row are skipped.
+			if trimmed != "" && !strings.HasPrefix(trimmed, "NAME") {
+				if vdev, ok := parseVdevLine(trimmed, current.Name); ok {
+					current.Vdevs = append(current.Vdevs, vdev)
+				}
+			}
+		case inConfig:
+			// unindented line (errors:, status:, next pool:) ends the table
+			inConfig = false
+		}
+	}
+	return pools, scanner.Err()
+}
+
+// parseScanLine maps a `scan:` line to a ScrubStatus.
+func parseScanLine(line string) ScrubStatus {
+	var scrub ScrubStatus
+	switch {
+	case strings.Contains(line, "in progress"):
+		scrub.State = "SCANNING"
+	case strings.Contains(line, "canceled"):
+		scrub.State = "CANCELED"
+	case strings.Contains(line, "repaired"), strings.Contains(line, "resilvered"):
+		scrub.State = "FINISHED"
+	default:
+		scrub.State = "NONE"
+	}
+	if m := progressRe.FindStringSubmatch(line); m != nil {
+		scrub.Progress = m[1] + "%"
+	}
+	if m := errorsRe.FindStringSubmatch(line); m != nil {
+		if n, err := strconv.ParseUint(m[1], 10, 64); err == nil {
+			scrub.Errors = n
+		}
+	}
+	return scrub
+}
+
+// parseVdevLine parses one row of the config table. Rows have the shape
+// "NAME STATE READ WRITE CKSUM [extra...]". The first data row is the pool
+// itself and is skipped since it duplicates pool-level info.
+func parseVdevLine(line, poolName string) (VdevStatus, bool) {
+	fields := strings.Fields(line)
+	if len(fields) < 5 {
+		return VdevStatus{}, false
+	}
+	if fields[0] == poolName {
+		return VdevStatus{}, false
+	}
+	read, err1 := strconv.ParseUint(fields[2], 10, 64)
+	write, err2 := strconv.ParseUint(fields[3], 10, 64)
+	cksum, err3 := strconv.ParseUint(fields[4], 10, 64)
+	if err1 != nil || err2 != nil || err3 != nil {
+		return VdevStatus{}, false
+	}
+	return VdevStatus{
+		Name:         fields[0],
+		State:        fields[1],
+		ReadErrs:     read,
+		WriteErrs:    write,
+		ChecksumErrs: cksum,
+	}, true
+}

agent/zfs/zfs_test.go

@@ -0,0 +1,143 @@
+//go:build testing
+
+package zfs
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func fixturePath(name string) string {
+	return filepath.Join("..", "test-data", "zfs", name)
+}
+
+func TestParseZpoolListOutput(t *testing.T) {
+	data, err := os.ReadFile(fixturePath("zpool_list.txt"))
+	require.NoError(t, err)
+
+	pools, err := parseZpoolListOutput(data)
+	require.NoError(t, err)
+	require.Len(t, pools, 2)
+
+	assert.Equal(t, PoolStat{Name: "tank", Size: 23999000000000, Alloc: 12000000000000, Free: 11999000000000, Health: "ONLINE"}, pools[0])
+	assert.Equal(t, PoolStat{Name: "rpool", Size: 1200000000000, Alloc: 900000000000, Free: 300000000000, Health: "DEGRADED"}, pools[1])
+}
+
+func TestParseZpoolListOutputIgnoresEmptyLines(t *testing.T) {
+	pools, err := parseZpoolListOutput([]byte("tank\t100\t50\t50\tONLINE\n\n"))
+	require.NoError(t, err)
+	require.Len(t, pools, 1)
+	assert.Equal(t, "tank", pools[0].Name)
+}
+
+func TestParseZpoolListOutputNoPools(t *testing.T) {
+	pools, err := parseZpoolListOutput([]byte("no pools available\n"))
+	require.NoError(t, err)
+	assert.Empty(t, pools)
+}
+
+func TestParseZpoolListOutputRejectsMalformedLine(t *testing.T) {
+	_, err := parseZpoolListOutput([]byte("tank\t100\t50\n"))
+	require.Error(t, err)
+
+	_, err = parseZpoolListOutput([]byte("tank\tnotanumber\t50\t50\tONLINE\n"))
+	require.Error(t, err)
+}
+
+func TestParseZfsListOutput(t *testing.T) {
+	data, err := os.ReadFile(fixturePath("zfs_list.txt"))
+	require.NoError(t, err)
+
+	datasets, err := parseZfsListOutput(data)
+	require.NoError(t, err)
+	require.Len(t, datasets, 9)
+
+	// Mountpoint with a space must be kept intact (tab-split only).
+	assert.Equal(t, "/tank/my media", datasets[3].Mountpoint)
+	// Unmounted datasets/zvols report "-".
+	assert.Equal(t, "-", datasets[4].Mountpoint)
+	assert.Equal(t, uint64(12000000000000), datasets[0].Used)
+	assert.Equal(t, uint64(11999000000000), datasets[0].Avail)
+}
+
+func TestParseZpoolStatusOutput(t *testing.T) {
+	data, err := os.ReadFile(fixturePath("zpool_status.txt"))
+	require.NoError(t, err)
+
+	pools, err := parseZpoolStatusOutput(data)
+	require.NoError(t, err)
+	require.Len(t, pools, 2)
+
+	tank := pools[0]
+	assert.Equal(t, "tank", tank.Name)
+	assert.Equal(t, "ONLINE", tank.State)
+	assert.Equal(t, "FINISHED", tank.Scrub.State)
+	assert.Equal(t, "", tank.Scrub.Progress)
+	assert.Equal(t, uint64(0), tank.Scrub.Errors)
+	// Pool row itself is skipped; mirror + 2 disks remain.
+	require.Len(t, tank.Vdevs, 3)
+	assert.Equal(t, "mirror-0", tank.Vdevs[0].Name)
+	assert.Equal(t, "sda", tank.Vdevs[1].Name)
+	assert.Equal(t, "sdb", tank.Vdevs[2].Name)
+
+	rpool := pools[1]
+	assert.Equal(t, "rpool", rpool.Name)
+	assert.Equal(t, "DEGRADED", rpool.State)
+	assert.Equal(t, "SCANNING", rpool.Scrub.State)
+	assert.Equal(t, "10.00%", rpool.Scrub.Progress)
+	require.Len(t, rpool.Vdevs, 3)
+	assert.Equal(t, "FAULTED", rpool.Vdevs[2].State)
+	assert.Equal(t, uint64(1), rpool.Vdevs[2].ReadErrs)
+	assert.Equal(t, uint64(2), rpool.Vdevs[2].WriteErrs)
+	assert.Equal(t, uint64(3), rpool.Vdevs[2].ChecksumErrs)
+}
+
+func TestParseScanLine(t *testing.T) {
+	assert.Equal(t, "FINISHED", parseScanLine("scan: scrub repaired 0B in 00:05:12 with 0 errors on Sun Jun  1 02:00:12 2025").State)
+	assert.Equal(t, uint64(3), parseScanLine("scan: scrub repaired 10G in 01:00:00 with 3 errors on Sun Jun  1 02:00:12 2025").Errors)
+	assert.Equal(t, "SCANNING", parseScanLine("scan: scrub in progress since Sun Jun  8 01:00:00 2025").State)
+	assert.Equal(t, "CANCELED", parseScanLine("scan: scrub canceled on Sun Jun  1 02:00:12 2025").State)
+	assert.Equal(t, "FINISHED", parseScanLine("scan: resilvered 1.23G in 00:01:00 with 0 errors on Sun Jun  1 02:00:12 2025").State)
+	assert.Equal(t, "NONE", parseScanLine("scan: none requested").State)
+}
+
+func TestCommandOutputForcesLocaleAndTimesOut(t *testing.T) {
+	t.Setenv("BESZEL_ZFS_COMMAND_HELPER", "1")
+	out, err := commandOutput(os.Args[0], "-test.run=TestZfsCommandHelperProcess", "--", "locale")
+	require.NoError(t, err)
+	assert.Equal(t, "C/C", string(out))
+
+	oldTimeout := commandTimeout
+	commandTimeout = 20 * time.Millisecond
+	t.Cleanup(func() { commandTimeout = oldTimeout })
+	_, err = commandOutput(os.Args[0], "-test.run=TestZfsCommandHelperProcess", "--", "sleep")
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "timed out")
+}
+
+func TestZfsCommandHelperProcess(t *testing.T) {
+	if os.Getenv("BESZEL_ZFS_COMMAND_HELPER") != "1" {
+		return
+	}
+	mode := ""
+	for i, arg := range os.Args {
+		if arg == "--" && i+1 < len(os.Args) {
+			mode = os.Args[i+1]
+			break
+		}
+	}
+	switch strings.TrimSpace(mode) {
+	case "locale":
+		_, _ = fmt.Printf("%s/%s", os.Getenv("LC_ALL"), os.Getenv("LANG"))
+	case "sleep":
+		time.Sleep(time.Second)
+	}
+	os.Exit(0)
+}

agent/zfs/zfs_unsupported.go

@@ -7,3 +7,7 @@ import "errors"
 func ARCSize() (uint64, error) {
 	return 0, errors.ErrUnsupported
 }
+
+func PoolKernelStats() ([]PoolKernelStat, error) {
+	return nil, errors.ErrUnsupported
+}

beszel.go

@@ -6,7 +6,7 @@ import "github.com/blang/semver"
 
 const (
 	// Version is the current version of the application.
-	Version = "0.18.8"
+	Version = "0.19.0"
 	// AppName is the name of the application.
 	AppName = "beszel"
 )
@@ -16,3 +16,6 @@ var MinVersionCbor = semver.MustParse("0.12.0")
 
 // MinVersionAgentResponse is the minimum supported version for AgentResponse compatibility.
 var MinVersionAgentResponse = semver.MustParse("0.13.0")
+
+// MinVersionZfsData is the minimum agent version that supports ZFS detail requests.
+var MinVersionZfsData = semver.MustParse("0.18.9")

go.mod

@@ -1,25 +1,26 @@
 module github.com/henrygd/beszel
 
-go 1.26.6
+go 1.27.1
 
 require (
 	github.com/blang/semver v3.5.1+incompatible
 	github.com/coreos/go-systemd/v22 v22.7.0
-	github.com/ebitengine/purego v0.10.2
+	github.com/distribution/reference v0.6.0
-	github.com/fxamacker/cbor/v2 v2.9.2
+	github.com/ebitengine/purego v0.11.0
+	github.com/fxamacker/cbor/v2 v2.9.3
 	github.com/gliderlabs/ssh v0.3.8
-	github.com/google/uuid v1.6.0
 	github.com/lxzan/gws v1.10.1
-	github.com/nicholas-fedor/shoutrrr v0.17.0
+	github.com/nicholas-fedor/shoutrrr v0.20.0
+	github.com/opencontainers/go-digest v1.0.0
 	github.com/pocketbase/dbx v1.12.0
-	github.com/pocketbase/pocketbase v0.39.11
+	github.com/pocketbase/pocketbase v0.40.2
-	github.com/shirou/gopsutil/v4 v4.26.7
+	github.com/shirou/gopsutil/v4 v4.26.8
 	github.com/spf13/cast v1.10.0
 	github.com/spf13/cobra v1.10.2
 	github.com/spf13/pflag v1.0.10
-	github.com/stretchr/testify v1.12.0
+	github.com/stretchr/testify v1.12.1
-	golang.org/x/crypto v0.55.0
+	golang.org/x/crypto v0.56.0
-	golang.org/x/exp v0.0.0-20260813180055-c1d0aacb2297
+	golang.org/x/exp v0.0.0-20260824195058-e88cd73687aa
 	golang.org/x/net v0.58.0
 	golang.org/x/sys v0.47.0
 	gopkg.in/yaml.v3 v3.0.1
@@ -41,9 +42,10 @@ require (
 	github.com/go-sql-driver/mysql v1.9.1 // indirect
 	github.com/godbus/dbus/v5 v5.2.2 // indirect
 	github.com/golang-jwt/jwt/v5 v5.3.1 // indirect
+	github.com/google/uuid v1.6.0 // indirect
 	github.com/gorilla/websocket v1.5.3 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
-	github.com/klauspost/compress v1.19.2 // indirect
+	github.com/klauspost/compress v1.20.0 // indirect
 	github.com/lufia/plan9stats v0.0.0-20260802145828-341c2f0c90b5 // indirect
 	github.com/mattn/go-colorable v0.1.15 // indirect
 	github.com/mattn/go-isatty v0.0.24 // indirect
@@ -55,13 +57,14 @@ require (
 	github.com/tklauser/numcpus v0.12.0 // indirect
 	github.com/x448/float16 v0.8.4 // indirect
 	github.com/yusufpapurcu/wmi v1.2.4 // indirect
+	go.yaml.in/yaml/v3 v3.0.5 // indirect
 	golang.org/x/image v0.45.0 // indirect
 	golang.org/x/oauth2 v0.36.0 // indirect
 	golang.org/x/sync v0.22.0 // indirect
 	golang.org/x/term v0.45.0 // indirect
 	golang.org/x/text v0.41.0 // indirect
-	modernc.org/libc v1.74.1 // indirect
+	modernc.org/libc v1.74.4 // indirect
 	modernc.org/mathutil v1.7.1 // indirect
-	modernc.org/memory v1.12.0 // indirect
+	modernc.org/memory v1.12.1 // indirect
-	modernc.org/sqlite v1.55.0 // indirect
+	modernc.org/sqlite v1.57.0 // indirect
 )

go.sum

@@ -15,12 +15,14 @@ github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6N
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/disintegration/imaging v1.6.2 h1:w1LecBlG2Lnp8B3jk5zSuNqd7b4DXhcjwek1ei82L+c=
 github.com/disintegration/imaging v1.6.2/go.mod h1:44/5580QXChDfwIclfc/PCwrr44amcmDAg8hxG0Ewe4=
+github.com/distribution/reference v0.6.0 h1:0IXCQ5g4/QMHHkarYzh5l+u8T3t73zM5QvfrDyIgxBk=
+github.com/distribution/reference v0.6.0/go.mod h1:BbU0aIcezP1/5jX/8MP0YiH4SdvB5Y4f/wlDRiLyi3E=
 github.com/domodwyer/mailyak/v3 v3.6.2 h1:x3tGMsyFhTCaxp6ycgR0FE/bu5QiNp+hetUuCOBXMn8=
 github.com/domodwyer/mailyak/v3 v3.6.2/go.mod h1:lOm/u9CyCVWHeaAmHIdF4RiKVxKUT/H5XX10lIKAL6c=
 github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
-github.com/ebitengine/purego v0.10.2 h1:W809HbnvzAxgdm+aOvlSekrM16wGCdT/e76+9tS7gzE=
+github.com/ebitengine/purego v0.11.0 h1:jhp/D+Nyv7UUW8HAcmcjt2N2rYrYi9m3SL21k0Ua/NI=
-github.com/ebitengine/purego v0.10.2/go.mod h1:iIjxzd6CiRiOG0UyXP+V1+jWqUXVjPKLAI0mRfJZTmQ=
+github.com/ebitengine/purego v0.11.0/go.mod h1:DCHPP08djqhNSoTfImcnHYQRZmd0qhakvrozqaEYhGQ=
 github.com/eclipse/paho.golang v0.23.0 h1:KHgl2wz6EJo7cMBmkuhpt7C576vP+kpPv7jjvSyR6Mk=
 github.com/eclipse/paho.golang v0.23.0/go.mod h1:nQRhTkoZv8EAiNs5UU0/WdQIx2NrnWUpL9nsGJTQN04=
 github.com/fatih/color v1.19.0 h1:Zp3PiM21/9Ld6FzSKyL5c/BULoe/ONr9KlbYVOfG8+w=
@@ -29,8 +31,8 @@ github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHk
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/fsnotify/fsnotify v1.10.1 h1:b0/UzAf9yR5rhf3RPm9gf3ehBPpf0oZKIjtpKrx59Ho=
 github.com/fsnotify/fsnotify v1.10.1/go.mod h1:TLheqan6HD6GBK6PrDWyDPBaEV8LspOxvPSjC+bVfgo=
-github.com/fxamacker/cbor/v2 v2.9.2 h1:X4Ksno9+x3cz0TZv69ec1hxP/+tymuR8PXQJyDwfh78=
+github.com/fxamacker/cbor/v2 v2.9.3 h1:oQBnFATpNdY8gJHTndDDv5Xl4QqNaz51G5LLEPhng3Q=
-github.com/fxamacker/cbor/v2 v2.9.2/go.mod h1:vM4b+DJCtHn+zz7h3FFp/hDAI9WNWCsZj23V5ytsSxQ=
+github.com/fxamacker/cbor/v2 v2.9.3/go.mod h1:vM4b+DJCtHn+zz7h3FFp/hDAI9WNWCsZj23V5ytsSxQ=
 github.com/gabriel-vasile/mimetype v1.4.15 h1:05iP/CYtZ/w455R/KZM6rZ5ieAdh99UPtd+d3YzLmaI=
 github.com/gabriel-vasile/mimetype v1.4.15/go.mod h1:azpTcoLcDZRNgFou5j+APrqQx9HqVPWa6ijYQIIVswQ=
 github.com/ganigeorgiev/fexpr v0.6.0 h1:Fza3O/QMBKEudUvxV862qe6GjxM60GJjjKytdp+VQus=
@@ -54,8 +56,8 @@ github.com/golang-jwt/jwt/v5 v5.3.1/go.mod h1:fxCRLWMO43lRc8nhHWY6LGqRcf+1gQWArs
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
 github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
-github.com/google/pprof v0.0.0-20260802141513-ef3492d7dac3 h1:LMLX+LgTNWpfvCBdFebv6EsYotImrt/Ppc5cXIriCSo=
+github.com/google/pprof v0.0.0-20260906184651-6331bc6350fe h1:QAinXoAFJdGQYztXn3VpFey7KCwpedbZ/EkzbplQ0cY=
-github.com/google/pprof v0.0.0-20260802141513-ef3492d7dac3/go.mod h1:jl5iWTm0/hd5PjEYEOuwAJ57L/CibdZfrqZ5XA5GrCk=
+github.com/google/pprof v0.0.0-20260906184651-6331bc6350fe/go.mod h1:jl5iWTm0/hd5PjEYEOuwAJ57L/CibdZfrqZ5XA5GrCk=
 github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
 github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/gorilla/websocket v1.5.3 h1:saDtZ6Pbx/0u+bgYQ3q96pZgCzfhKXGPqt7kZ72aNNg=
@@ -67,8 +69,8 @@ github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLf
 github.com/jarcoal/httpmock v1.4.2 h1:dKwiP/9zITCPfBLsDn3kchbSOu16JrnxtVEmL0fPRcI=
 github.com/jarcoal/httpmock v1.4.2/go.mod h1:ftW1xULwo+j0R0JJkJIIi7UKigZUXCLLanykgjwBXL0=
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
-github.com/klauspost/compress v1.19.2 h1:hMRETovs/pu/dVWN7zIT1PGG8t509MwT6bO7XSi26R8=
+github.com/klauspost/compress v1.20.0 h1:a3C1ke2ohxFymNlb2HWAHjDeKCI90scRskErZkR0ezA=
-github.com/klauspost/compress v1.19.2/go.mod h1:cwPg85FWrGar70rWktvGQj8/hthj3wpl0PGDogxkrSQ=
+github.com/klauspost/compress v1.20.0/go.mod h1:LUdAzn7YLVvxLpc7y3V1m40wESHTgc1422pwwBSKYuI=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
@@ -83,19 +85,21 @@ github.com/mattn/go-isatty v0.0.24 h1:tGZZoVgT/KiqK1c8ocVLeDS8BSWMRd47J3Lbz7vsRe
 github.com/mattn/go-isatty v0.0.24/go.mod h1:nMCL3Zebbrt45jsMDgnfIwz6ydEQApk5oEI3HqDio6A=
 github.com/ncruces/go-strftime v1.0.0 h1:HMFp8mLCTPp341M/ZnA4qaf7ZlsbTc+miZjCLOFAw7w=
 github.com/ncruces/go-strftime v1.0.0/go.mod h1:Fwc5htZGVVkseilnfgOVb9mKy6w1naJmn9CehxcKcls=
-github.com/nicholas-fedor/shoutrrr v0.17.0 h1:xfp3z5QbE8jXvUhUEwWDk47SJ/b912VoB8MJJDU+q4E=
+github.com/nicholas-fedor/shoutrrr v0.20.0 h1:hMAxIYlfAeZ1FcTDgU0kUOvVXUsOirWo8IWlnzGLkac=
-github.com/nicholas-fedor/shoutrrr v0.17.0/go.mod h1:s4ldyLs6uwBy9lIjYrY+8lyTqJtPvZSrILw0CyMLock=
+github.com/nicholas-fedor/shoutrrr v0.20.0/go.mod h1:hgde37yNWCXh8+N6WemyDRMNYLOFTf326GsBx8Z7CFA=
-github.com/onsi/ginkgo/v2 v2.32.0 h1:Hw7s2pVrQo/8Yz5N77qdnpHaoc+c6cC9WIV1Jce+J6E=
+github.com/onsi/ginkgo/v2 v2.32.1 h1:6tlvcDm/3sE8lGJbZ4+d4mO3RLy24/tQWOFzVSQNIfw=
-github.com/onsi/ginkgo/v2 v2.32.0/go.mod h1:+aXOY+vzZ5mu2iI2HpTZUPmM//oQfsNFX6gU9kNcA44=
+github.com/onsi/ginkgo/v2 v2.32.1/go.mod h1:+aXOY+vzZ5mu2iI2HpTZUPmM//oQfsNFX6gU9kNcA44=
-github.com/onsi/gomega v1.42.1 h1:iN1rCUX+44NZ1Dc97MPoeFYbFR0vh8zxoxMFwKdyZ6I=
+github.com/onsi/gomega v1.43.0 h1:VlG/1FxqNxhSO+lq/OHBNaaqwiBK/mO8JbVkX9Y+FeU=
-github.com/onsi/gomega v1.42.1/go.mod h1:REff/hsDsodHoKlWsP2mAPhu1+5/6hVYNf9rIEBpeSg=
+github.com/onsi/gomega v1.43.0/go.mod h1:REff/hsDsodHoKlWsP2mAPhu1+5/6hVYNf9rIEBpeSg=
+github.com/opencontainers/go-digest v1.0.0 h1:apOUWs51W5PlhuyGyz9FCeeBIOUDA/6nW8Oi/yOhh5U=
+github.com/opencontainers/go-digest v1.0.0/go.mod h1:0JzlMkj0TRzQZfJkVvzbP0HBR3IKzErnv2BNG4W4MAM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/pocketbase/dbx v1.12.0 h1:/oLErM+A0b4xI0PWTGPqSDVjzix48PqI/bng2l0PzoA=
 github.com/pocketbase/dbx v1.12.0/go.mod h1:xXRCIAKTHMgUCyCKZm55pUOdvFziJjQfXaWKhu2vhMs=
 github.com/pocketbase/ozzo-validation/v4 v4.3.0 h1:uKBDVma7bZqgR2a6AwE+k9hkuDFfiZMpBHQdZ1z3iQs=
 github.com/pocketbase/ozzo-validation/v4 v4.3.0/go.mod h1:6XNjSTw/Jb2F8LOkKO3oyzIWExbrGiYoS4uVxVwz90g=
-github.com/pocketbase/pocketbase v0.39.11 h1:cl/Kh13ukof/4BAEku3OozYrLl85M5/bmH62Ny4szFc=
+github.com/pocketbase/pocketbase v0.40.2 h1:7gTqvt3bmilkphyZZ1QNhX19g3BXHqT7ynDyU81RVT4=
-github.com/pocketbase/pocketbase v0.39.11/go.mod h1:5CaCvp/52fZJ5/qyYsqpCGyVue/kjez889cQAATD2cY=
+github.com/pocketbase/pocketbase v0.40.2/go.mod h1:jc3YuyToy+ZXM4CeO7uSCN/htgR8yv+tjSE3eJZ8eh8=
 github.com/power-devops/perfstat v0.0.0-20260805114148-88456608a4f6 h1:jL3a8soXdzuTCcRnKhOmtcsVOObdDTFf4O2B403HPRU=
 github.com/power-devops/perfstat v0.0.0-20260805114148-88456608a4f6/go.mod h1:OmDBASR4679mdNQnz2pUhc2G8CO2JrUAVFDRBDP/hJE=
 github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec h1:W09IVJc94icq4NjY3clb7Lk8O1qJ8BdBEF8z0ibU0rE=
@@ -103,8 +107,8 @@ github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec/go.mod h1:qq
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
-github.com/shirou/gopsutil/v4 v4.26.7 h1:IXzpHz/dkMRYAhKkOXr1HB6SuzWU3eoyyeWe7g3bNZc=
+github.com/shirou/gopsutil/v4 v4.26.8 h1:YQMTF/1J50B5+Y0vlo1eDRf5DoR7Gk69hY+8wjYkQeo=
-github.com/shirou/gopsutil/v4 v4.26.7/go.mod h1:5O9FjBiXoTDFatIWjZZosqj4pV0DRtLx598xGbBehzM=
+github.com/shirou/gopsutil/v4 v4.26.8/go.mod h1:5O9FjBiXoTDFatIWjZZosqj4pV0DRtLx598xGbBehzM=
 github.com/spf13/cast v1.10.0 h1:h2x0u2shc1QuLHfxi+cTJvs30+ZAHOGRic8uyGTDWxY=
 github.com/spf13/cast v1.10.0/go.mod h1:jNfB8QC9IA6ZuY2ZjDp0KtFO2LZZlg4S/7bzP6qqeHo=
 github.com/spf13/cobra v1.10.2 h1:DMTTonx5m65Ic0GOoRY2c16WCbHxOOw6xxezuLaBpcU=
@@ -116,8 +120,8 @@ github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+
 github.com/stretchr/objx v0.5.3 h1:jmXUvGomnU1o3W/V5h2VEradbpJDwGrzugQQvL0POH4=
 github.com/stretchr/objx v0.5.3/go.mod h1:rDQraq+vQZU7Fde9LOZLr8Tax6zZvy4kuNKF+QYS+U0=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
-github.com/stretchr/testify v1.12.0 h1:K6Mr6jO9JICuend/5xzTM03ydSV3vdNRYAdPSukj8uI=
+github.com/stretchr/testify v1.12.1 h1:EuwCh5fleGS7H32xRwO3wRGT7DxrDhLAT6FF8MpWDWE=
-github.com/stretchr/testify v1.12.0/go.mod h1:bOYBZb5qJ00vPzWfIqBUZPaxK8jWiXc6d3ErP4Ca9Gw=
+github.com/stretchr/testify v1.12.1/go.mod h1:MDEgiDPPsNp5cuIrHPPCyornHKgEVbtFUmoNlxoYthg=
 github.com/tklauser/go-sysconf v0.4.0 h1:7H0uAN+7RkwWRaxhYXDLqa5V3LPrJeV8wmD9dRUgPQU=
 github.com/tklauser/go-sysconf v0.4.0/go.mod h1:8mTNWyog7H+MpKijp4VmKJAd2bbYQ2zuUwkYRbUArPI=
 github.com/tklauser/numcpus v0.12.0 h1:NR85qdvHA9pFse3x3weVZ0r0ST8R6l5RHbZrlRaqob4=
@@ -132,10 +136,10 @@ go.yaml.in/yaml/v3 v3.0.4/go.mod h1:DhzuOOF2ATzADvBadXxruRBLzYTpT36CKvDb3+aBEFg=
 go.yaml.in/yaml/v3 v3.0.5 h1:N6y/pJk8buWs9NY5ERU2HSMfm+IuD/OtfdAnq6kESPw=
 go.yaml.in/yaml/v3 v3.0.5/go.mod h1:HVTZu1O7/Vkt2N+BFy8Zza+lnLsABggaTM2ZpNIGuKg=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.55.0 h1:+KWHjbgOaAQ66dh/YlkZKHlz9ZUlq61AFirAR9ntP8M=
+golang.org/x/crypto v0.56.0 h1:GUh5Ii4J5jtcseSMiRqr1jXCNHoxjeV9Fmekc2oLy6Y=
-golang.org/x/crypto v0.55.0/go.mod h1:uq0V9dE/fzQuJtbnL+2EhWOE63vo164FY8xqEnV9xis=
+golang.org/x/crypto v0.56.0/go.mod h1:OMW5y6CY9l38uPLmxU6l6pwcXp1obtLo3e6gT7gQR2I=
-golang.org/x/exp v0.0.0-20260813180055-c1d0aacb2297 h1:YXnL44eJ77R+ji4/ooy8UsXIhz+lbi2Qgdlc8iRN0gY=
+golang.org/x/exp v0.0.0-20260824195058-e88cd73687aa h1:QSyA8ishJCyT21kER9KwNt0b7BM3iRK4x9QXhjN5Fdk=
-golang.org/x/exp v0.0.0-20260813180055-c1d0aacb2297/go.mod h1:Mkmymgv+uMpSQ/XxJ/7GpdrdYoqm3u72jEbpCLiJmNk=
+golang.org/x/exp v0.0.0-20260824195058-e88cd73687aa/go.mod h1:zeBbvyFKDaLwa7CH/zI8KXt7gTl14SF7sO08Pl5jBCM=
 golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
 golang.org/x/image v0.45.0 h1:FMb1nTbH5H9vF55SriQHgFw5GnNL9Jg6L25BwXKzhB0=
 golang.org/x/image v0.45.0/go.mod h1:n62x/7RqlwXDvGsSU4u6IUTUf6KghUZ9Bt7cG/T9Fx4=
@@ -164,17 +168,16 @@ golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGm
 golang.org/x/tools v0.49.0 h1:3NI7VXzL9+1WZD52Dx2ttoPwD5DWrFGpl9mFZDlmisI=
 golang.org/x/tools v0.49.0/go.mod h1:SJNXV9DBKT0UbdttsQjbfJlAE/q+y36++zo3uL3N0Oo=
 google.golang.org/appengine v1.6.5/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
-gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/yaml.v1 v1.0.0-20140924161607-9f9df34309c0/go.mod h1:WDnlLJ4WF5VGsH/HVa3CI79GS0ol3YnhVnKP89i0kNg=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 howett.net/plist v1.0.1 h1:37GdZ8tP09Q35o9ych3ehygcsL+HqKSwzctveSlarvM=
 howett.net/plist v1.0.1/go.mod h1:lqaXoTrLY4hg8tnEzNru53gicrbv7rrk+2xJA/7hw9g=
-modernc.org/cc/v4 v4.29.0 h1:CXgwL8cvxmyzBQZzbSl/6xFtMCryb6u8IOqDci39cgc=
+modernc.org/cc/v4 v4.29.1 h1:MKgdCV3WykTSPqpVrnxdEDS0HEd2FHpKZDzxzU5LyeI=
-modernc.org/cc/v4 v4.29.0/go.mod h1:OnovgIhbbMXMu1aISnJ0wvVD1KnW+cAUJkIrAWh+kVI=
+modernc.org/cc/v4 v4.29.1/go.mod h1:OnovgIhbbMXMu1aISnJ0wvVD1KnW+cAUJkIrAWh+kVI=
 modernc.org/ccgo/v4 v4.34.6 h1:sBgfIwyN0TQ9C5hwIeuqyeAKyMWnbvj2fvpF4L11uzU=
 modernc.org/ccgo/v4 v4.34.6/go.mod h1:SZ8YcN9NG7XVsQYdm6jYBvi8PQP1qi+kqB6OhjqI3Fk=
 modernc.org/fileutil v1.4.0 h1:j6ZzNTftVS054gi281TyLjHPp6CPHr2KCxEXjEbD6SM=
@@ -185,18 +188,18 @@ modernc.org/gc/v3 v3.1.4 h1:2g65LGVSmFQrXeITAw97x7hCRvZFcyE1uDP+7Vng7JI=
 modernc.org/gc/v3 v3.1.4/go.mod h1:HFK/6AGESC7Ex+EZJhJ2Gni6cTaYpSMmU/cT9RmlfYY=
 modernc.org/goabi0 v0.2.0 h1:HvEowk7LxcPd0eq6mVOAEMai46V+i7Jrj13t4AzuNks=
 modernc.org/goabi0 v0.2.0/go.mod h1:CEFRnnJhKvWT1c1JTI3Avm+tgOWbkOu5oPA8eH8LnMI=
-modernc.org/libc v1.74.1 h1:bdR4VTKFMC4966QSNZ05XLGI/VwzVa2kTUX51Dm0riQ=
+modernc.org/libc v1.74.4 h1:fX1Omw4o2/1C2iRkkIsrQTasJQldLhRmuPreXLoWs9k=
-modernc.org/libc v1.74.1/go.mod h1:uH4t5bOx3G3g9Xcmj10YKlTcVISlRDwv8VoQJG9n8Os=
+modernc.org/libc v1.74.4/go.mod h1:eeQAS9W3sZeKYMFubydxJpII9ybHWshk+7or7bLG9co=
 modernc.org/mathutil v1.7.1 h1:GCZVGXdaN8gTqB1Mf/usp1Y/hSqgI2vAGGP4jZMCxOU=
 modernc.org/mathutil v1.7.1/go.mod h1:4p5IwJITfppl0G4sUEDtCr4DthTaT47/N3aT6MhfgJg=
-modernc.org/memory v1.12.0 h1:twkmYNkGXCvtYWzoux02jtK6eovjZbdI0uHFUYp6kuU=
+modernc.org/memory v1.12.1 h1:nFMiWrpStgZczNl6XI9GnIk/rWhYIyHGUaR04pGbp9g=
-modernc.org/memory v1.12.0/go.mod h1:/JP4VbVC+K5sU2wZi9bHoq2MAkCnrt2r98UGeSK7Mjw=
+modernc.org/memory v1.12.1/go.mod h1:/JP4VbVC+K5sU2wZi9bHoq2MAkCnrt2r98UGeSK7Mjw=
 modernc.org/opt v0.2.0 h1:tGyef5ApycA7FSEOMraay9SaTk5zmbx7Tu+cJs4QKZg=
 modernc.org/opt v0.2.0/go.mod h1:03fq9lsNfvkYSfxrfUhZCWPk1lm4cq4N+Bh//bEtgns=
 modernc.org/sortutil v1.2.1 h1:+xyoGf15mM3NMlPDnFqrteY07klSFxLElE2PVuWIJ7w=
 modernc.org/sortutil v1.2.1/go.mod h1:7ZI3a3REbai7gzCLcotuw9AC4VZVpYMjDzETGsSMqJE=
-modernc.org/sqlite v1.55.0 h1:hIFh0MCH0rGinQ/4KYb5/UbCkRkb+UP+OkLCVWa5MTM=
+modernc.org/sqlite v1.57.0 h1:qNQP6xnx5M0ISNtlnxoOX0+cD5bJ0/gr9aMmndFczzg=
-modernc.org/sqlite v1.55.0/go.mod h1:4ntCLuNmnH8+GNqjka1wNg7KJd5/Hi5FYp8K+XQ7GZw=
+modernc.org/sqlite v1.57.0/go.mod h1:yCJ2cmAaIkHQ25oXWrF8H4O1lIfPYPR26yCEDj2P3pQ=
 modernc.org/strutil v1.2.1 h1:UneZBkQA+DX2Rp35KcM69cSsNES9ly8mQWD71HKlOA0=
 modernc.org/strutil v1.2.1/go.mod h1:EHkiggD70koQxjVdSBM3JKM7k6L0FbGE5eymy9i3B9A=
 modernc.org/token v1.1.0 h1:Xl7Ap9dKaEs5kLoOQeQmPWevfnk/DM5qcLcYlA8ys6Y=

internal/alerts/alerts.go

@@ -48,6 +48,7 @@ type SystemAlertFsStats struct {
 // Values pulled from system_stats.stats that are relevant to alerts.
 type SystemAlertStats struct {
 	Cpu          float64                       `json:"cpu"`
+	CpuBreakdown []float64                     `json:"cpub"`
 	Mem          float64                       `json:"mp"`
 	Disk         float64                       `json:"dp"`
 	Bandwidth    [2]uint64                     `json:"b"`
@@ -57,12 +58,19 @@ type SystemAlertStats struct {
 	Battery      [2]uint8                      `json:"bat"`
 	Batteries    map[string]uint8              `json:"bats"`
 	ExtraFs      map[string]SystemAlertFsStats `json:"efs"`
+	ZfsPools     map[string]SystemAlertZfsPool `json:"z"`
 }
 
 type SystemAlertGPUData struct {
 	Usage float64 `json:"u"`
 }
 
+type SystemAlertZfsPool struct {
+	Raw   bool    `json:"raw,omitempty"`
+	Total float64 `json:"d"`
+	Used  float64 `json:"du"`
+}
+
 type SystemAlertData struct {
 	systemRecord *core.Record
 	alertData    CachedAlertData
@@ -111,6 +119,9 @@ func (am *AlertManager) bindEvents() {
 	am.hub.OnRecordAfterUpdateSuccess("alerts").BindFunc(updateHistoryOnAlertUpdate)
 	am.hub.OnRecordAfterDeleteSuccess("alerts").BindFunc(resolveHistoryOnAlertDelete)
 	am.hub.OnRecordAfterUpdateSuccess("smart_devices").BindFunc(am.handleSmartDeviceAlert)
+	am.hub.OnRecordAfterCreateSuccess("zfs_pools").BindFunc(am.handleZfsPoolCreateAlert)
+	am.hub.OnRecordAfterUpdateSuccess("zfs_pools").BindFunc(am.handleZfsPoolAlert)
+	am.hub.OnRecordAfterDeleteSuccess("zfs_pools").BindFunc(resolveZfsPoolHistoryOnDelete)
 
 	am.hub.OnServe().BindFunc(func(e *core.ServeEvent) error {
 		// Populate all alerts into cache on startup
@@ -119,6 +130,9 @@ func (am *AlertManager) bindEvents() {
 		if err := resolveStatusAlerts(e.App); err != nil {
 			e.App.Logger().Error("Failed to resolve stale status alerts", "err", err)
 		}
+		if err := resolveSystemdAlerts(e.App); err != nil {
+			e.App.Logger().Error("Failed to resolve stale systemd alerts", "err", err)
+		}
 		if err := am.restorePendingStatusAlerts(); err != nil {
 			e.App.Logger().Error("Failed to restore pending status alerts", "err", err)
 		}
@@ -218,8 +232,20 @@ func (am *AlertManager) SendAlert(data AlertMessageData) error {
 		am.hub.Logger().Error("Failed to unmarshal user settings", "err", err)
 	}
 	// send alerts via webhooks
+	send := sendPublicNotification
+	if len(userAlertSettings.Webhooks) > 0 {
+		// Read the owner's current role at delivery time, including for URLs
+		// saved before an admin was demoted. Never fall back on lookup failure.
+		owner, err := am.hub.FindRecordById("users", data.UserID)
+		if err != nil {
+			return fmt.Errorf("load notification owner: %w", err)
+		}
+		if owner.GetString("role") == "admin" {
+			send = shoutrrr.Send
+		}
+	}
 	for _, webhook := range userAlertSettings.Webhooks {
-		if err := am.SendShoutrrrAlert(webhook, data.Title, data.Message, data.Link, data.LinkText); err != nil {
+		if err := am.sendShoutrrrAlert(webhook, data.Title, data.Message, data.Link, data.LinkText, send); err != nil {
 			am.hub.Logger().Error("Failed to send shoutrrr alert", "err", err)
 		}
 	}
@@ -250,6 +276,10 @@ func (am *AlertManager) SendAlert(data AlertMessageData) error {
 
 // SendShoutrrrAlert sends an alert via a Shoutrrr URL
 func (am *AlertManager) SendShoutrrrAlert(notificationUrl, title, message, link, linkText string) error {
+	return am.sendShoutrrrAlert(notificationUrl, title, message, link, linkText, shoutrrr.Send)
+}
+
+func (am *AlertManager) sendShoutrrrAlert(notificationUrl, title, message, link, linkText string, send func(string, string) error) error {
 	// Parse the URL
 	parsedURL, err := url.Parse(notificationUrl)
 	if err != nil {
@@ -292,7 +322,7 @@ func (am *AlertManager) SendShoutrrrAlert(notificationUrl, title, message, link,
 	parsedURL.RawQuery = queryParams.Encode()
 	// log.Println("URL after modification:", parsedURL.String())
 
-	err = shoutrrr.Send(parsedURL.String(), message)
+	err = send(parsedURL.String(), message)
 
 	if err == nil {
 		am.hub.Logger().Info("Sent shoutrrr alert", "title", title)

internal/alerts/alerts_api.go

@@ -3,12 +3,11 @@ package alerts
 import (
 	"database/sql"
 	"errors"
-	"net"
 	"net/http"
-	"net/url"
 	"slices"
-	"strings"
 
+	"github.com/henrygd/beszel/internal/hub/utils"
+	"github.com/nicholas-fedor/shoutrrr"
 	"github.com/pocketbase/dbx"
 	"github.com/pocketbase/pocketbase/core"
 )
@@ -37,6 +36,9 @@ func UpsertUserAlerts(e *core.RequestEvent) error {
 
 	err = e.App.RunInTransaction(func(txApp core.App) error {
 		for _, systemId := range reqData.Systems {
+			if !userHasSystem(txApp, userID, systemId) {
+				continue
+			}
 			// find existing matching alert
 			alertRecord, err := txApp.FindFirstRecordByFilter(alertsCollection,
 				"system={:system} && name={:name} && user={:user}",
@@ -94,6 +96,9 @@ func DeleteUserAlerts(e *core.RequestEvent) error {
 
 	err = e.App.RunInTransaction(func(txApp core.App) error {
 		for _, systemId := range reqData.Systems {
+			if !userHasSystem(txApp, userID, systemId) {
+				continue
+			}
 			// Find existing alert to delete
 			alertRecord, err := txApp.FindFirstRecordByFilter("alerts",
 				"system={:system} && name={:name} && user={:user}",
@@ -122,6 +127,15 @@ func DeleteUserAlerts(e *core.RequestEvent) error {
 	return e.JSON(http.StatusOK, map[string]any{"success": true, "count": numDeleted})
 }
 
+func userHasSystem(app core.App, userID, systemID string) bool {
+	system, err := app.FindRecordById("systems", systemID)
+	if err != nil {
+		return false
+	}
+	shareAll, _ := utils.GetEnv("SHARE_ALL_SYSTEMS")
+	return shareAll == "true" || slices.Contains(system.GetStringSlice("users"), userID)
+}
+
 // SendTestNotification handles API request to send a test notification to a specified Shoutrrr URL
 func (am *AlertManager) SendTestNotification(e *core.RequestEvent) error {
 	var data struct {
@@ -131,62 +145,16 @@ func (am *AlertManager) SendTestNotification(e *core.RequestEvent) error {
 	if err != nil || data.URL == "" {
 		return e.BadRequestError("URL is required", err)
 	}
-	// Only allow admins to send test notifications to internal URLs
+	send := shoutrrr.Send
 	if !e.Auth.IsSuperuser() && e.Auth.GetString("role") != "admin" {
-		internalURL, err := isInternalURL(data.URL)
+		send = sendPublicNotification
-		if err != nil {
+	}
-			return e.BadRequestError(err.Error(), nil)
+	err = am.sendShoutrrrAlert(data.URL, "Test Alert", "This is a notification from Beszel.", am.hub.Settings().Meta.AppURL, "View Beszel", send)
-		}
+	if errors.Is(err, errInternalDestination) || errors.Is(err, errUnrestrictedService) {
-		if internalURL {
+		return e.ForbiddenError(err.Error(), nil)
-			return e.ForbiddenError("Only admins can send to internal destinations", nil)
-		}
 	}
-	err = am.SendShoutrrrAlert(data.URL, "Test Alert", "This is a notification from Beszel.", am.hub.Settings().Meta.AppURL, "View Beszel")
 	if err != nil {
 		return e.JSON(200, map[string]string{"err": err.Error()})
 	}
 	return e.JSON(200, map[string]bool{"err": false})
 }
-
-// isInternalURL checks if the given shoutrrr URL points to an internal destination (localhost or private IP)
-func isInternalURL(rawURL string) (bool, error) {
-	parsedURL, err := url.Parse(rawURL)
-	if err != nil {
-		return false, err
-	}
-
-	host := parsedURL.Hostname()
-	if host == "" {
-		return false, nil
-	}
-
-	if strings.EqualFold(host, "localhost") {
-		return true, nil
-	}
-
-	if ip := net.ParseIP(host); ip != nil {
-		return isInternalIP(ip), nil
-	}
-
-	// Some Shoutrrr URLs use the host position for service identifiers rather than a
-	// network hostname (for example, discord://token@webhookid). Restrict DNS lookups
-	// to names that look like actual hostnames so valid service URLs keep working.
-	if !strings.Contains(host, ".") {
-		return false, nil
-	}
-
-	ips, err := net.LookupIP(host)
-	if err != nil {
-		return false, nil
-	}
-
-	if slices.ContainsFunc(ips, isInternalIP) {
-		return true, nil
-	}
-
-	return false, nil
-}
-
-func isInternalIP(ip net.IP) bool {
-	return ip.IsPrivate() || ip.IsLoopback() || ip.IsUnspecified()
-}

internal/alerts/alerts_api_test.go

@@ -7,10 +7,11 @@ import (
 	"encoding/json"
 	"io"
 	"net/http"
+	"net/http/httptest"
 	"strings"
+	"sync/atomic"
 	"testing"
 
-	"github.com/henrygd/beszel/internal/alerts"
 	beszelTests "github.com/henrygd/beszel/internal/tests"
 	pbTests "github.com/pocketbase/pocketbase/tests"
 
@@ -29,31 +30,6 @@ func jsonReader(v any) io.Reader {
 	return bytes.NewReader(data)
 }
 
-func TestIsInternalURL(t *testing.T) {
-	testCases := []struct {
-		name     string
-		url      string
-		internal bool
-	}{
-		{name: "loopback ipv4", url: "generic://127.0.0.1", internal: true},
-		{name: "localhost hostname", url: "generic://localhost", internal: true},
-		{name: "localhost hostname", url: "generic+http://localhost/api/v1/postStuff", internal: true},
-		{name: "localhost hostname", url: "generic+http://127.0.0.1:8080/api/v1/postStuff", internal: true},
-		{name: "localhost hostname", url: "generic+https://beszel.dev/api/v1/postStuff", internal: false},
-		{name: "public ipv4", url: "generic://8.8.8.8", internal: false},
-		{name: "token style service url", url: "discord://abc123@123456789", internal: false},
-		{name: "single label service url", url: "slack://token@team/channel", internal: false},
-	}
-
-	for _, testCase := range testCases {
-		t.Run(testCase.name, func(t *testing.T) {
-			internal, err := alerts.IsInternalURL(testCase.url)
-			assert.NoError(t, err)
-			assert.Equal(t, testCase.internal, internal)
-		})
-	}
-}
-
 func TestUserAlertsApi(t *testing.T) {
 	hub, _ := beszelTests.NewTestHub(t.TempDir())
 	defer hub.Cleanup()
@@ -190,6 +166,30 @@ func TestUserAlertsApi(t *testing.T) {
 				assert.EqualValues(t, 3, user1Alerts, "should have 3 alerts")
 			},
 		},
+		{
+			Name:   "POST ignores systems the user cannot access",
+			Method: http.MethodPost,
+			URL:    "/api/beszel/user-alerts",
+			Headers: map[string]string{
+				"Authorization": user2Token,
+			},
+			ExpectedStatus:  200,
+			ExpectedContent: []string{"\"success\":true"},
+			TestAppFactory:  testAppFactory,
+			Body: jsonReader(map[string]any{
+				"name":    "CPU",
+				"systems": []string{system1.Id},
+				"value":   90,
+				"min":     10,
+			}),
+			BeforeTestFunc: func(t testing.TB, app *pbTests.TestApp, e *core.ServeEvent) {
+				beszelTests.ClearCollection(t, app, "alerts")
+			},
+			AfterTestFunc: func(t testing.TB, app *pbTests.TestApp, res *http.Response) {
+				alerts, _ := app.CountRecords("alerts")
+				assert.Zero(t, alerts)
+			},
+		},
 		{
 			Name:   "Overwrite: false, should not overwrite existing alert",
 			Method: http.MethodPost,
@@ -347,6 +347,31 @@ func TestUserAlertsApi(t *testing.T) {
 				assert.Zero(t, alerts, "should have 0 alerts")
 			},
 		},
+		{
+			Name:   "DELETE ignores systems the user cannot access",
+			Method: http.MethodDelete,
+			URL:    "/api/beszel/user-alerts",
+			Headers: map[string]string{
+				"Authorization": user2Token,
+			},
+			ExpectedStatus:  200,
+			ExpectedContent: []string{"\"count\":0", "\"success\":true"},
+			TestAppFactory:  testAppFactory,
+			Body: jsonReader(map[string]any{
+				"name":    "CPU",
+				"systems": []string{system1.Id},
+			}),
+			BeforeTestFunc: func(t testing.TB, app *pbTests.TestApp, e *core.ServeEvent) {
+				beszelTests.ClearCollection(t, app, "alerts")
+				beszelTests.CreateRecord(app, "alerts", map[string]any{
+					"name": "CPU", "system": system1.Id, "user": user2.Id, "value": 80,
+				})
+			},
+			AfterTestFunc: func(t testing.TB, app *pbTests.TestApp, res *http.Response) {
+				alerts, _ := app.CountRecords("alerts")
+				assert.EqualValues(t, 1, alerts)
+			},
+		},
 		{
 			Name:   "User 2 should not be able to delete alert of user 1",
 			Method: http.MethodDelete,
@@ -396,6 +421,17 @@ func TestSendTestNotification(t *testing.T) {
 	hub, user := beszelTests.GetHubWithUser(t)
 	defer hub.Cleanup()
 
+	var delivered atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		delivered.Add(1)
+	}))
+	defer server.Close()
+	localURL := "generic+" + server.URL
+
+	readonlyUser, err := beszelTests.CreateUserWithRole(hub, "readonly@example.com", "password123", "readonly")
+	assert.NoError(t, err)
+	readonlyToken, err := readonlyUser.NewAuthToken()
+	assert.NoError(t, err)
 	userToken, err := user.NewAuthToken()
 
 	adminUser, err := beszelTests.CreateUserWithRole(hub, "admin@example.com", "password123", "admin")
@@ -420,11 +456,11 @@ func TestSendTestNotification(t *testing.T) {
 			ExpectedContent: []string{"requires valid"},
 			TestAppFactory:  testAppFactory,
 			Body: jsonReader(map[string]any{
-				"url": "generic://127.0.0.1",
+				"url": localURL,
 			}),
 		},
 		{
-			Name:           "POST /test-notification - with external auth should succeed",
+			Name:           "POST /test-notification - invalid service reports error",
 			Method:         http.MethodPost,
 			URL:            "/api/beszel/test-notification",
 			TestAppFactory: testAppFactory,
@@ -432,7 +468,7 @@ func TestSendTestNotification(t *testing.T) {
 				"Authorization": userToken,
 			},
 			Body: jsonReader(map[string]any{
-				"url": "generic://8.8.8.8",
+				"url": "unknown://example.com",
 			}),
 			ExpectedStatus:  200,
 			ExpectedContent: []string{"\"err\":"},
@@ -474,10 +510,10 @@ func TestSendTestNotification(t *testing.T) {
 				"Authorization": adminUserToken,
 			},
 			Body: jsonReader(map[string]any{
-				"url": "generic://127.0.0.1",
+				"url": localURL,
 			}),
 			ExpectedStatus:  200,
-			ExpectedContent: []string{"\"err\":"},
+			ExpectedContent: []string{"\"err\":false"},
 		},
 		{
 			Name:           "POST /test-notification - internal url with superuser auth should succeed",
@@ -488,14 +524,28 @@ func TestSendTestNotification(t *testing.T) {
 				"Authorization": superuserToken,
 			},
 			Body: jsonReader(map[string]any{
-				"url": "generic://127.0.0.1",
+				"url": localURL,
 			}),
 			ExpectedStatus:  200,
 			ExpectedContent: []string{"\"err\":"},
 		},
 	}
 
+	for _, url := range []string{localURL, "smtp://user:pass@127.0.0.1/?fromAddress=sender@example.com&toAddresses=recipient@example.com", "mqtt://127.0.0.1/topic"} {
+		scenarios = append(scenarios, beszelTests.ApiScenario{
+			Name:            "readonly cannot send to " + url,
+			Method:          http.MethodPost,
+			URL:             "/api/beszel/test-notification",
+			TestAppFactory:  testAppFactory,
+			Headers:         map[string]string{"Authorization": readonlyToken},
+			Body:            jsonReader(map[string]any{"url": url}),
+			ExpectedStatus:  403,
+			ExpectedContent: []string{"Only admins"},
+		})
+	}
+
 	for _, scenario := range scenarios {
 		scenario.Test(t)
 	}
+	assert.EqualValues(t, 2, delivered.Load(), "only admin and superuser requests should reach the server")
 }

internal/alerts/alerts_cache.go

@@ -1,6 +1,8 @@
 package alerts
 
 import (
+	"time"
+
 	"github.com/pocketbase/dbx"
 	"github.com/pocketbase/pocketbase/core"
 	"github.com/pocketbase/pocketbase/tools/store"
@@ -8,13 +10,14 @@ import (
 
 // CachedAlertData represents the relevant fields of an alert record for status checking and updates.
 type CachedAlertData struct {
-	Id        string
+	Id           string
-	SystemID  string
+	SystemID     string
-	UserID    string
+	UserID       string
-	Name      string
+	Name         string
-	Value     float64
+	Value        float64
-	Triggered bool
+	Triggered    bool
-	Min       uint8
+	Min          uint8
+	PendingSince time.Time
 	// Created   types.DateTime
 }
 
@@ -26,6 +29,7 @@ func (a *CachedAlertData) PopulateFromRecord(record *core.Record) {
 	a.Value = record.GetFloat("value")
 	a.Triggered = record.GetBool("triggered")
 	a.Min = uint8(record.GetInt("min"))
+	a.PendingSince = record.GetDateTime("pending_since").Time()
 	// a.Created = record.GetDateTime("created")
 }
 

internal/alerts/alerts_container.go

@@ -0,0 +1,318 @@
+package alerts
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/henrygd/beszel/internal/entities/container"
+	"github.com/henrygd/beszel/internal/entities/system"
+
+	"github.com/pocketbase/pocketbase/core"
+)
+
+const (
+	// containerAlertName is the value stored in the alerts.name field for this alert type.
+	containerAlertName = "ContainerHealth"
+
+	// containerLogMaxLines caps how many matched (error/fatal) log lines are kept.
+	containerLogMaxLines = 12
+	// containerLogFallbackLines is how many trailing raw log lines are used when no
+	// line matches "error" or "fatal", so the notification still carries some context.
+	containerLogFallbackLines = 6
+	// containerLogExcerptMaxChars bounds a single container's log excerpt so a
+	// handful of containers can't blow past Discord's message size limit.
+	containerLogExcerptMaxChars = 500
+	// containerAlertMaxLogged is the max number of unhealthy containers we fetch
+	// and embed logs for in a single alert message.
+	containerAlertMaxLogged = 2
+	// containerAlertMessageMaxChars is a final safety cap on the whole message body.
+	containerAlertMessageMaxChars = 1800
+)
+
+// FetchContainerLogsFunc retrieves recent logs for a container ID from its
+// connected agent. Implementations should apply their own timeout. This is a
+// type alias (not a defined type) so it satisfies the hubLike interface in
+// internal/hub/systems, which declares the same func signature without
+// importing this package.
+type FetchContainerLogsFunc = func(containerID string) (string, error)
+
+// containerAlertTarget is an immutable snapshot of the fields needed after the
+// alert fires. Keeping agent-owned container records out of notification work
+// avoids retaining and concurrently reading data that is refreshed in place.
+type containerAlertTarget struct {
+	id   string
+	name string
+}
+
+// HandleContainerAlerts checks configured "ContainerHealth" alerts for a system
+// against the Docker container health data included in the latest agent update.
+// It persists when containers first become unhealthy, fires from a fresh poll
+// once the configured delay has elapsed, and resolves once containers recover.
+// fetchLogs is used when an alert actually fires so the notification can include
+// a log excerpt (prioritizing lines containing "error"/"fatal") for context.
+func (am *AlertManager) HandleContainerAlerts(systemRecord *core.Record, data *system.CombinedData, fetchLogs FetchContainerLogsFunc) error {
+	alerts := am.alertsCache.GetAlertsByName(systemRecord.Id, containerAlertName)
+	if len(alerts) == 0 {
+		return nil
+	}
+	if data.Containers == nil {
+		// An unknown Docker state must not resolve a triggered alert or count
+		// toward the minimum unhealthy duration.
+		var result error
+		for _, alertData := range alerts {
+			if err := am.clearPendingContainerAlert(alertData); err != nil {
+				result = errors.Join(result, err)
+			}
+		}
+		return result
+	}
+
+	var unhealthy []*container.Stats
+	for _, c := range data.Containers {
+		if c.Health == container.DockerHealthUnhealthy {
+			unhealthy = append(unhealthy, c)
+		}
+	}
+
+	systemName := systemRecord.GetString("name")
+	now := time.Now().UTC()
+	var result error
+	for _, alertData := range alerts {
+		if len(unhealthy) > 0 {
+			if alertData.Triggered {
+				continue
+			}
+			min := max(1, int(alertData.Min))
+			if alertData.PendingSince.IsZero() {
+				pendingSince, err := am.setPendingContainerAlert(alertData, now)
+				if err != nil {
+					result = errors.Join(result, err)
+					continue
+				}
+				if pendingSince.IsZero() {
+					continue
+				}
+				alertData.PendingSince = pendingSince
+				if min > 1 {
+					continue
+				}
+			}
+			if min > 1 && now.Before(alertData.PendingSince.Add(time.Duration(min)*time.Minute)) {
+				continue
+			}
+			if err := am.sendContainerHealthAlert(true, systemName, alertData, snapshotContainerAlertTargets(unhealthy), fetchLogs); err != nil {
+				result = errors.Join(result, err)
+			}
+			continue
+		}
+
+		// no unhealthy containers right now
+		if err := am.clearPendingContainerAlert(alertData); err != nil {
+			result = errors.Join(result, err)
+		}
+		if !alertData.Triggered {
+			continue
+		}
+		if err := am.sendContainerHealthAlert(false, systemName, alertData, nil, fetchLogs); err != nil {
+			result = errors.Join(result, err)
+		}
+	}
+	return result
+}
+
+func snapshotContainerAlertTargets(containers []*container.Stats) []containerAlertTarget {
+	targets := make([]containerAlertTarget, len(containers))
+	for i, c := range containers {
+		targets[i] = containerAlertTarget{id: c.Id, name: c.Name}
+	}
+	return targets
+}
+
+// setPendingContainerAlert durably records the first unhealthy observation and
+// returns the persisted generation used to claim delivery.
+func (am *AlertManager) setPendingContainerAlert(alertData CachedAlertData, since time.Time) (time.Time, error) {
+	record, err := am.hub.FindRecordById("alerts", alertData.Id)
+	if err != nil {
+		return time.Time{}, err
+	}
+	if record.GetBool("triggered") {
+		return time.Time{}, nil
+	}
+	if pendingSince := record.GetDateTime("pending_since").Time(); !pendingSince.IsZero() {
+		return pendingSince, nil
+	}
+	// PocketBase date fields are persisted with millisecond precision. Normalize
+	// before saving so the update-hook cache and a subsequent database read agree.
+	since = since.Truncate(time.Millisecond)
+	record.Set("pending_since", since)
+	return since, am.hub.Save(record)
+}
+
+func (am *AlertManager) clearPendingContainerAlert(alertData CachedAlertData) error {
+	if alertData.PendingSince.IsZero() {
+		return nil
+	}
+	record, err := am.hub.FindRecordById("alerts", alertData.Id)
+	if err != nil {
+		return err
+	}
+	if record.GetDateTime("pending_since").Time().IsZero() {
+		return nil
+	}
+	record.Set("pending_since", nil)
+	return am.hub.Save(record)
+}
+
+// claimPendingContainerAlert marks an alert triggered only if the pending
+// generation is still current. A healthy/unknown update can clear the timestamp
+// while logs are being fetched, causing this claim to become a no-op.
+func (am *AlertManager) claimPendingContainerAlert(alertData CachedAlertData) (bool, error) {
+	record, err := am.hub.FindRecordById("alerts", alertData.Id)
+	if err != nil {
+		return false, err
+	}
+	pendingSince := record.GetDateTime("pending_since").Time()
+	if record.GetBool("triggered") || pendingSince.IsZero() || pendingSince.UnixMilli() != alertData.PendingSince.UnixMilli() {
+		return false, nil
+	}
+	record.Set("pending_since", nil)
+	record.Set("triggered", true)
+	return true, am.hub.Save(record)
+}
+
+// CancelPendingContainerAlerts clears pending container-health durations for a
+// system. Called when monitoring pauses or the system goes down.
+func (am *AlertManager) CancelPendingContainerAlerts(systemID string) {
+	for _, alertData := range am.alertsCache.GetAlertsByName(systemID, containerAlertName) {
+		if err := am.clearPendingContainerAlert(alertData); err != nil {
+			am.hub.Logger().Error("Failed to clear pending container alert", "err", err)
+		}
+	}
+}
+
+// sendContainerHealthAlert updates the alert's triggered state and sends the
+// notification. When unhealthy is true, it embeds a log excerpt (prioritizing
+// error/fatal lines) for up to containerAlertMaxLogged of the affected containers.
+func (am *AlertManager) sendContainerHealthAlert(unhealthy bool, systemName string, alertData CachedAlertData, containers []containerAlertTarget, fetchLogs FetchContainerLogsFunc) error {
+	link := am.hub.MakeLink("system", alertData.SystemID)
+	linkText := "View " + systemName
+
+	if !unhealthy {
+		if err := am.setAlertTriggered(alertData, false); err != nil {
+			return err
+		}
+		title := fmt.Sprintf("%s containers are healthy ✅", systemName)
+		return am.SendAlert(AlertMessageData{
+			UserID:   alertData.UserID,
+			SystemID: alertData.SystemID,
+			Title:    title,
+			Message:  strings.TrimSuffix(title, " ✅"),
+			Link:     link,
+			LinkText: linkText,
+		})
+	}
+
+	names := make([]string, len(containers))
+	for i, c := range containers {
+		names[i] = c.name
+	}
+
+	var title string
+	if len(names) == 1 {
+		title = fmt.Sprintf("Unhealthy container %s on %s \U0001F534", names[0], systemName)
+	} else {
+		title = fmt.Sprintf("%d unhealthy containers on %s \U0001F534", len(names), systemName)
+	}
+
+	var body strings.Builder
+	fmt.Fprintf(&body, "Unhealthy: %s", strings.Join(names, ", "))
+	body.WriteString(am.buildContainerLogsSection(containers, fetchLogs))
+
+	message := body.String()
+	if len(message) > containerAlertMessageMaxChars {
+		message = message[:containerAlertMessageMaxChars] + "\n…(truncated)"
+	}
+
+	claimed, err := am.claimPendingContainerAlert(alertData)
+	if err != nil || !claimed {
+		return err
+	}
+
+	return am.SendAlert(AlertMessageData{
+		UserID:   alertData.UserID,
+		SystemID: alertData.SystemID,
+		Title:    title,
+		Message:  message,
+		Link:     link,
+		LinkText: linkText,
+	})
+}
+
+// buildContainerLogsSection attempts to fetch and format log excerpts for up to
+// containerAlertMaxLogged unhealthy containers, to append to an alert message.
+func (am *AlertManager) buildContainerLogsSection(containers []containerAlertTarget, fetchLogs FetchContainerLogsFunc) string {
+	if fetchLogs == nil {
+		return ""
+	}
+
+	var section strings.Builder
+	attempts := min(len(containers), containerAlertMaxLogged)
+	for _, c := range containers[:attempts] {
+		rawLogs, err := fetchLogs(c.id)
+		if err != nil {
+			am.hub.Logger().Warn("Failed to fetch container logs for alert", "container", c.name, "err", err)
+			continue
+		}
+		excerpt := buildContainerLogExcerpt(rawLogs)
+		if excerpt == "" {
+			continue
+		}
+		fmt.Fprintf(&section, "\n\n%s logs:\n```\n%s\n```", c.name, excerpt)
+	}
+
+	if len(containers) > containerAlertMaxLogged {
+		fmt.Fprintf(&section, "\n\n(+%d more unhealthy container(s), logs omitted)", len(containers)-containerAlertMaxLogged)
+	}
+
+	return section.String()
+}
+
+// buildContainerLogExcerpt filters raw container log output down to the lines
+// most likely to explain why the container is unhealthy: lines containing
+// "error" or "fatal" (case-insensitive) are preferred. If none match, the tail
+// of the raw output is used instead so the notification still carries context.
+func buildContainerLogExcerpt(raw string) string {
+	raw = strings.TrimSpace(raw)
+	if raw == "" {
+		return ""
+	}
+	lines := strings.Split(raw, "\n")
+
+	var matched []string
+	for _, line := range lines {
+		line = strings.TrimRight(line, "\r")
+		if line == "" {
+			continue
+		}
+		lower := strings.ToLower(line)
+		if strings.Contains(lower, "error") || strings.Contains(lower, "fatal") {
+			matched = append(matched, line)
+		}
+	}
+
+	selected := matched
+	if len(selected) == 0 {
+		start := max(0, len(lines)-containerLogFallbackLines)
+		selected = lines[start:]
+	} else if len(selected) > containerLogMaxLines {
+		selected = selected[len(selected)-containerLogMaxLines:]
+	}
+
+	excerpt := strings.TrimSpace(strings.Join(selected, "\n"))
+	if len(excerpt) > containerLogExcerptMaxChars {
+		excerpt = "…" + excerpt[len(excerpt)-containerLogExcerptMaxChars:]
+	}
+	return excerpt
+}

internal/alerts/alerts_container_test.go

@@ -0,0 +1,349 @@
+//go:build testing
+
+package alerts_test
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+	"testing/synctest"
+	"time"
+
+	"github.com/henrygd/beszel/internal/alerts"
+	"github.com/henrygd/beszel/internal/entities/container"
+	"github.com/henrygd/beszel/internal/entities/system"
+	beszelTests "github.com/henrygd/beszel/internal/tests"
+	"github.com/pocketbase/pocketbase/core"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type containerAlertTestFixture struct {
+	hub          *beszelTests.TestHub
+	am           *alerts.AlertManager
+	alertID      string
+	systemRecord *core.Record
+}
+
+func newContainerAlertTestFixture(t *testing.T, min int) *containerAlertTestFixture {
+	t.Helper()
+
+	hub, user := beszelTests.GetHubWithUser(t)
+
+	systems, err := beszelTests.CreateSystems(hub, 1, user.Id, "up")
+	require.NoError(t, err)
+	systemRecord := systems[0]
+
+	userSettings, err := hub.FindFirstRecordByFilter("user_settings", "user={:user}", map[string]any{"user": user.Id})
+	require.NoError(t, err)
+	userSettings.Set("settings", `{"emails":["test@example.com"],"webhooks":[]}`)
+	require.NoError(t, hub.Save(userSettings))
+
+	alertRecord, err := beszelTests.CreateRecord(hub, "alerts", map[string]any{
+		"name":   "ContainerHealth",
+		"system": systemRecord.Id,
+		"user":   user.Id,
+		"min":    min,
+	})
+	require.NoError(t, err)
+	assert.False(t, alertRecord.GetBool("triggered"), "Alert should not be triggered initially")
+
+	return &containerAlertTestFixture{
+		hub:          hub,
+		am:           alerts.NewTestAlertManagerWithoutWorker(hub),
+		alertID:      alertRecord.Id,
+		systemRecord: systemRecord,
+	}
+}
+
+func (f *containerAlertTestFixture) cleanup() {
+	f.hub.Cleanup()
+}
+
+func (f *containerAlertTestFixture) submit(t *testing.T, containers []*container.Stats, fetchLogs alerts.FetchContainerLogsFunc) {
+	t.Helper()
+	data := &system.CombinedData{Containers: containers}
+	require.NoError(t, f.am.HandleContainerAlerts(f.systemRecord, data, fetchLogs))
+}
+
+func (f *containerAlertTestFixture) submitInvalid(t *testing.T) {
+	t.Helper()
+	require.NoError(t, f.am.HandleContainerAlerts(f.systemRecord, &system.CombinedData{}, nil))
+}
+
+func (f *containerAlertTestFixture) assertTriggered(t *testing.T, triggered bool, message string) {
+	t.Helper()
+	alertRecord, err := f.hub.FindRecordById("alerts", f.alertID)
+	require.NoError(t, err)
+	assert.Equal(t, triggered, alertRecord.GetBool("triggered"), message)
+}
+
+func (f *containerAlertTestFixture) assertPending(t *testing.T, pending bool) {
+	t.Helper()
+	alertRecord, err := f.hub.FindRecordById("alerts", f.alertID)
+	require.NoError(t, err)
+	assert.Equal(t, pending, !alertRecord.GetDateTime("pending_since").Time().IsZero())
+}
+
+func waitForContainerAlert(d time.Duration) {
+	time.Sleep(d)
+	synctest.Wait()
+}
+
+func healthyContainer(name string) *container.Stats {
+	return &container.Stats{Name: name, Id: "abc123def456", Health: container.DockerHealthHealthy}
+}
+
+func unhealthyContainer(name string) *container.Stats {
+	return &container.Stats{Name: name, Id: "abc123def456", Health: container.DockerHealthUnhealthy}
+}
+
+func TestContainerHealthAlertTriggersAndResolves(t *testing.T) {
+	fixture := newContainerAlertTestFixture(t, 1)
+	defer fixture.cleanup()
+
+	synctest.Test(t, func(t *testing.T) {
+		fixture.submit(t, []*container.Stats{unhealthyContainer("web")}, nil)
+
+		fixture.assertTriggered(t, true, "A one-minute alert should trigger on the first unhealthy update")
+		require.Equal(t, 1, fixture.hub.TestMailer.TotalSend(), "An email should have been sent")
+
+		msg := fixture.hub.TestMailer.LastMessage()
+		assert.Contains(t, msg.Subject, "web", "Subject should name the unhealthy container")
+		assert.Contains(t, strings.ToLower(msg.Subject), "unhealthy")
+
+		fixture.submit(t, []*container.Stats{unhealthyContainer("web")}, nil)
+		fixture.assertPending(t, false)
+
+		fixture.submitInvalid(t)
+		fixture.assertTriggered(t, true, "An invalid container snapshot should not resolve the alert")
+		assert.Equal(t, 1, fixture.hub.TestMailer.TotalSend(), "An invalid snapshot should not send a recovery")
+
+		fixture.submit(t, []*container.Stats{}, nil)
+		waitForContainerAlert(time.Second)
+
+		fixture.assertTriggered(t, false, "Alert should resolve once the container is healthy again")
+		assert.Equal(t, 2, fixture.hub.TestMailer.TotalSend(), "A second email should have been sent for the recovery")
+		assert.Contains(t, fixture.hub.TestMailer.LastMessage().Subject, " healthy")
+	})
+}
+
+func TestContainerHealthAlertInvalidSnapshotCancelsPending(t *testing.T) {
+	fixture := newContainerAlertTestFixture(t, 5)
+	defer fixture.cleanup()
+
+	synctest.Test(t, func(t *testing.T) {
+		fixture.submit(t, []*container.Stats{unhealthyContainer("db")}, nil)
+		fixture.assertPending(t, true)
+		waitForContainerAlert(time.Minute)
+		fixture.submitInvalid(t)
+		fixture.assertPending(t, false)
+		waitForContainerAlert(10 * time.Minute)
+		fixture.submit(t, []*container.Stats{unhealthyContainer("db")}, nil)
+
+		fixture.assertTriggered(t, false, "Stale unhealthy data should not trigger an alert")
+		fixture.assertPending(t, true)
+		assert.Equal(t, 0, fixture.hub.TestMailer.TotalSend())
+	})
+}
+
+func TestContainerHealthAlertSystemDownCancelsPending(t *testing.T) {
+	fixture := newContainerAlertTestFixture(t, 5)
+	defer fixture.cleanup()
+
+	// Use the hub's alert manager because the system-manager status hook invokes
+	// cancellation on that instance.
+	am := fixture.hub.GetAlertManager()
+	require.NoError(t, am.HandleContainerAlerts(
+		fixture.systemRecord,
+		&system.CombinedData{Containers: []*container.Stats{unhealthyContainer("db")}},
+		nil,
+	))
+	fixture.assertPending(t, true)
+
+	fixture.systemRecord.Set("status", "down")
+	require.NoError(t, fixture.hub.Save(fixture.systemRecord))
+
+	fixture.assertPending(t, false)
+}
+
+func TestContainerHealthAlertResolvesBeforeMinDelayCancelsPending(t *testing.T) {
+	fixture := newContainerAlertTestFixture(t, 5)
+	defer fixture.cleanup()
+
+	synctest.Test(t, func(t *testing.T) {
+		fixture.submit(t, []*container.Stats{unhealthyContainer("db")}, nil)
+		waitForContainerAlert(time.Minute)
+
+		fixture.assertTriggered(t, false, "Alert should not fire until the min delay elapses")
+		fixture.assertPending(t, true)
+		assert.Equal(t, 0, fixture.hub.TestMailer.TotalSend())
+
+		// container recovers before the 5 minute delay elapses
+		fixture.submit(t, []*container.Stats{healthyContainer("db")}, nil)
+		waitForContainerAlert(10 * time.Minute)
+		fixture.submit(t, []*container.Stats{healthyContainer("db")}, nil)
+
+		fixture.assertTriggered(t, false, "Alert should remain untriggered")
+		fixture.assertPending(t, false)
+		assert.Equal(t, 0, fixture.hub.TestMailer.TotalSend(), "No email should be sent for a container that recovered before the delay")
+	})
+}
+
+func TestContainerHealthAlertPreservesPendingDurationAcrossManagerRestart(t *testing.T) {
+	fixture := newContainerAlertTestFixture(t, 2)
+	defer fixture.cleanup()
+
+	synctest.Test(t, func(t *testing.T) {
+		fixture.submit(t, []*container.Stats{unhealthyContainer("db")}, nil)
+		waitForContainerAlert(30 * time.Second)
+
+		restarted := alerts.NewTestAlertManagerWithoutWorker(fixture.hub)
+		waitForContainerAlert(91 * time.Second)
+		require.NoError(t, restarted.HandleContainerAlerts(
+			fixture.systemRecord,
+			&system.CombinedData{Containers: []*container.Stats{unhealthyContainer("db")}},
+			nil,
+		))
+
+		fixture.assertTriggered(t, true, "Restart should preserve the original unhealthy start time")
+		fixture.assertPending(t, false)
+		assert.Equal(t, 1, fixture.hub.TestMailer.TotalSend())
+	})
+}
+
+func TestContainerHealthAlertClaimsPendingTimestampAtDatabasePrecision(t *testing.T) {
+	fixture := newContainerAlertTestFixture(t, 1)
+	defer fixture.cleanup()
+
+	alertRecord, err := fixture.hub.FindRecordById("alerts", fixture.alertID)
+	require.NoError(t, err)
+	// PocketBase persists dates to milliseconds, while record update hooks can
+	// retain the original sub-millisecond value in the in-memory alert cache.
+	alertRecord.Set("pending_since", time.Now().UTC().Add(-2*time.Minute).Truncate(time.Millisecond).Add(123*time.Nanosecond))
+	require.NoError(t, fixture.hub.Save(alertRecord))
+
+	fixture.submit(t, []*container.Stats{unhealthyContainer("db")}, nil)
+
+	fixture.assertTriggered(t, true, "Equivalent persisted and cached timestamps should claim the alert")
+	fixture.assertPending(t, false)
+	assert.Equal(t, 1, fixture.hub.TestMailer.TotalSend())
+}
+
+func TestContainerHealthAlertRecoveryWhileFetchingLogsCancelsDelivery(t *testing.T) {
+	fixture := newContainerAlertTestFixture(t, 1)
+	defer fixture.cleanup()
+
+	synctest.Test(t, func(t *testing.T) {
+		fetchLogs := func(containerID string) (string, error) {
+			fixture.submit(t, []*container.Stats{healthyContainer("api")}, nil)
+			return "FATAL stale failure", nil
+		}
+		fixture.submit(t, []*container.Stats{unhealthyContainer("api")}, fetchLogs)
+
+		fixture.assertTriggered(t, false, "Recovery should cancel delivery while logs are fetched")
+		fixture.assertPending(t, false)
+		assert.Equal(t, 0, fixture.hub.TestMailer.TotalSend())
+	})
+}
+
+func TestContainerHealthAlertIncludesLogExcerpt(t *testing.T) {
+	fixture := newContainerAlertTestFixture(t, 1)
+	defer fixture.cleanup()
+
+	rawLogs := strings.Join([]string{
+		"2026-08-16T10:00:00Z booting",
+		"2026-08-16T10:00:01Z ERROR could not reach upstream",
+		"2026-08-16T10:00:02Z FATAL giving up after 3 retries",
+	}, "\n")
+	fetchLogs := func(containerID string) (string, error) {
+		assert.Equal(t, "abc123def456", containerID)
+		return rawLogs, nil
+	}
+
+	synctest.Test(t, func(t *testing.T) {
+		fixture.submit(t, []*container.Stats{unhealthyContainer("api")}, fetchLogs)
+
+		fixture.assertTriggered(t, true, "Alert should be triggered")
+		require.Equal(t, 1, fixture.hub.TestMailer.TotalSend())
+
+		body := fixture.hub.TestMailer.LastMessage().Text
+		assert.Contains(t, body, "could not reach upstream")
+		assert.Contains(t, body, "giving up after 3 retries")
+		assert.NotContains(t, body, "booting", "non error/fatal lines should be dropped when matches exist")
+	})
+}
+
+func TestContainerHealthAlertSkipsLogsOnFetchError(t *testing.T) {
+	fixture := newContainerAlertTestFixture(t, 1)
+	defer fixture.cleanup()
+
+	fetchLogs := func(containerID string) (string, error) {
+		return "", fmt.Errorf("agent unreachable")
+	}
+
+	synctest.Test(t, func(t *testing.T) {
+		fixture.submit(t, []*container.Stats{unhealthyContainer("api")}, fetchLogs)
+
+		fixture.assertTriggered(t, true, "Alert should still be triggered even if logs can't be fetched")
+		require.Equal(t, 1, fixture.hub.TestMailer.TotalSend())
+	})
+}
+
+func TestContainerHealthAlertCapsLogFetchAttempts(t *testing.T) {
+	fixture := newContainerAlertTestFixture(t, 1)
+	defer fixture.cleanup()
+
+	containers := make([]*container.Stats, 100)
+	for i := range containers {
+		containers[i] = &container.Stats{
+			Name:   fmt.Sprintf("container-%d", i),
+			Id:     fmt.Sprintf("id-%d", i),
+			Health: container.DockerHealthUnhealthy,
+		}
+	}
+	attempts := 0
+	fetchLogs := func(containerID string) (string, error) {
+		attempts++
+		return "", fmt.Errorf("agent unreachable")
+	}
+
+	synctest.Test(t, func(t *testing.T) {
+		fixture.submit(t, containers, fetchLogs)
+
+		fixture.assertTriggered(t, true, "Alert should still fire when log retrieval fails")
+		assert.Equal(t, 2, attempts, "Log retrieval should attempt at most two containers")
+		require.Equal(t, 1, fixture.hub.TestMailer.TotalSend())
+	})
+}
+
+func TestBuildContainerLogExcerptPrefersErrorAndFatalLines(t *testing.T) {
+	raw := strings.Join([]string{
+		"2026-08-16T10:00:00Z starting up",
+		"2026-08-16T10:00:01Z listening on :8080",
+		"2026-08-16T10:00:02Z ERROR failed to connect to db",
+		"2026-08-16T10:00:03Z retrying connection",
+		"2026-08-16T10:00:04Z FATAL could not recover, exiting",
+	}, "\n")
+
+	excerpt := alerts.BuildContainerLogExcerpt(raw)
+	assert.Contains(t, excerpt, "failed to connect to db")
+	assert.Contains(t, excerpt, "could not recover, exiting")
+	assert.NotContains(t, excerpt, "starting up", "non-matching lines should be dropped when error/fatal lines exist")
+}
+
+func TestBuildContainerLogExcerptFallsBackToTailWhenNoMatches(t *testing.T) {
+	var lines []string
+	for i := range 20 {
+		lines = append(lines, fmt.Sprintf("line %d: all good here", i))
+	}
+	raw := strings.Join(lines, "\n")
+
+	excerpt := alerts.BuildContainerLogExcerpt(raw)
+	assert.Contains(t, excerpt, "line 19", "should keep the tail of the output")
+	assert.NotContains(t, excerpt, "line 0:", "should not keep the very start when falling back to a short tail")
+}
+
+func TestBuildContainerLogExcerptEmpty(t *testing.T) {
+	assert.Equal(t, "", alerts.BuildContainerLogExcerpt("   \n  \n"))
+}

internal/alerts/alerts_system.go

@@ -13,8 +13,41 @@ import (
 	"github.com/pocketbase/pocketbase/tools/types"
 )
 
+var cpuStateAlerts = map[string]struct {
+	index int
+	label string
+}{
+	"CPUIOWait": {2, "CPU I/O Wait"},
+	"CPUSteal":  {3, "CPU Steal Time"},
+}
+
+func cpuStateAlertValue(name string, breakdown []float64) (float64, bool) {
+	state, ok := cpuStateAlerts[name]
+	if !ok || len(breakdown) < 5 {
+		return 0, false
+	}
+	var total float64
+	for _, value := range breakdown {
+		total += value
+	}
+	if total <= 0 {
+		return 0, false
+	}
+	return breakdown[state.index], true
+}
+
 func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *system.CombinedData) error {
-	alerts := am.alertsCache.GetAlertsExcludingNames(systemRecord.Id, "Status")
+	// Systemd alerts are binary state, not numeric thresholds, so they're handled
+	// separately. They read their own state from the database and don't use data.
+	if err := am.HandleSystemdAlerts(systemRecord); err != nil {
+		am.hub.Logger().Error("Error handling systemd alerts", "err", err)
+	}
+
+	if data == nil {
+		return nil
+	}
+
+	alerts := am.alertsCache.GetAlertsExcludingNames(systemRecord.Id, "Status", alertNameSystemdFailed, containerAlertName)
 	if len(alerts) == 0 {
 		return nil
 	}
@@ -44,6 +77,14 @@ func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *syst
 					maxUsedPct = usedPct
 				}
 			}
+			for _, pool := range data.Stats.ZfsPools {
+				if pool != nil && !pool.Raw && pool.Total > 0 {
+					usedPct := pool.Used / pool.Total * 100
+					if usedPct > maxUsedPct {
+						maxUsedPct = usedPct
+					}
+				}
+			}
 			val = maxUsedPct
 		case "Temperature":
 			if data.Info.DashboardTemp < 1 {
@@ -67,6 +108,11 @@ func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *syst
 				continue
 			}
 			val = float64(data.Stats.Battery[0])
+		default:
+			var ok bool
+			if val, ok = cpuStateAlertValue(name, data.Stats.CpuBreakdown); !ok {
+				continue
+			}
 		}
 
 		triggered := alertData.Triggered
@@ -208,6 +254,16 @@ func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *syst
 						alert.mapSums[key] += float32(fs.DiskUsed / fs.DiskTotal * 100)
 					}
 				}
+				// add zfs pool usage from historical record
+				for key, pool := range stats.ZfsPools {
+					if !pool.Raw && pool.Total > 0 {
+						zfsKey := zfsDiskAlertKey(key)
+						if _, ok := alert.mapSums[zfsKey]; !ok {
+							alert.mapSums[zfsKey] = 0.0
+						}
+						alert.mapSums[zfsKey] += float32(pool.Used / pool.Total * 100)
+					}
+				}
 			case "Temperature":
 				if alert.mapSums == nil {
 					alert.mapSums = make(map[string]float32, len(stats.Temperatures))
@@ -241,13 +297,20 @@ func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *syst
 				}
 				alert.val += float64(stats.Battery[0])
 			default:
-				continue
+				value, ok := cpuStateAlertValue(alert.name, stats.CpuBreakdown)
+				if !ok {
+					continue
+				}
+				alert.val += value
 			}
 			alert.count++
 		}
 	}
 	// sum up vals for each alert
 	for _, alert := range validAlerts {
+		if alert.count == 0 {
+			continue
+		}
 		switch alert.name {
 		case "Disk":
 			maxPct := float32(0)
@@ -255,7 +318,12 @@ func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *syst
 				sumPct := float32(value)
 				if sumPct > maxPct {
 					maxPct = sumPct
-					alert.descriptor = fmt.Sprintf("Usage of %s", key)
+					alert.descriptor = diskAlertDescriptor(key)
+					if poolKey, ok := strings.CutPrefix(key, "zfs:"); ok {
+						if pool := data.Stats.ZfsPools[poolKey]; pool != nil && pool.DisplayName != "" {
+							alert.descriptor = diskAlertDescriptor(zfsDiskAlertKey(pool.DisplayName))
+						}
+					}
 				}
 			}
 			alert.val = float64(maxPct / float32(alert.count))
@@ -301,6 +369,17 @@ func (am *AlertManager) HandleSystemAlerts(systemRecord *core.Record, data *syst
 	return nil
 }
 
+func zfsDiskAlertKey(poolName string) string {
+	return "zfs:" + poolName
+}
+
+func diskAlertDescriptor(key string) string {
+	if poolName, ok := strings.CutPrefix(key, "zfs:"); ok {
+		return fmt.Sprintf("Usage of storage pool %s", poolName)
+	}
+	return fmt.Sprintf("Usage of %s", key)
+}
+
 func hasRepresentativeBattery(legacy [2]uint8, batteries map[string]uint8) bool {
 	return legacy != [2]uint8{} || len(batteries) > 0
 }
@@ -309,6 +388,9 @@ func (am *AlertManager) sendSystemAlert(alert SystemAlertData) {
 	// log.Printf("Sending alert %s: val %f | count %d | threshold %f\n", alert.name, alert.val, alert.count, alert.threshold)
 	systemName := alert.systemRecord.GetString("name")
 
+	if state, ok := cpuStateAlerts[alert.name]; ok {
+		alert.name = state.label
+	}
 	// change Disk to Disk usage
 	if alert.name == "Disk" {
 		alert.name += " usage"
@@ -320,7 +402,7 @@ func (am *AlertManager) sendSystemAlert(alert SystemAlertData) {
 
 	// make title alert name lowercase if not CPU or GPU
 	titleAlertName := alert.name
-	if titleAlertName != "CPU" && titleAlertName != "GPU" {
+	if titleAlertName != "CPU" && titleAlertName != "GPU" && !strings.HasPrefix(titleAlertName, "CPU") {
 		titleAlertName = strings.ToLower(titleAlertName)
 	}
 

internal/alerts/alerts_system_test.go

@@ -146,6 +146,20 @@ func setCPUAlertValue(info *system.Info, stats *system.Stats, value float64) {
 	stats.Cpu = value
 }
 
+func setCPUStateAlertValue(_ *system.Info, stats *system.Stats, value []float64) {
+	stats.CpuBreakdown = value
+}
+
+var cpuStateAlertTests = []struct {
+	name     string
+	trigger  []float64
+	resolve  []float64
+	baseline []float64
+}{
+	{"CPUIOWait", []float64{0, 0, 51, 0, 49}, []float64{0, 0, 48, 0, 52}, []float64{0, 0, 10, 0, 90}},
+	{"CPUSteal", []float64{0, 0, 0, 51, 49}, []float64{0, 0, 0, 48, 52}, []float64{0, 0, 0, 10, 90}},
+}
+
 func setMemoryAlertValue(info *system.Info, stats *system.Stats, value float64) {
 	info.MemPct = value
 	stats.MemPct = value
@@ -191,6 +205,11 @@ func setBatteryAlertValue(info *system.Info, stats *system.Stats, value [2]uint8
 
 func TestSystemAlertsOneMin(t *testing.T) {
 	testOneMinuteSystemAlert(t, "CPU", 50, setCPUAlertValue, 51, 49)
+	for _, test := range cpuStateAlertTests {
+		t.Run(test.name, func(t *testing.T) {
+			testOneMinuteSystemAlert(t, test.name, 50, setCPUStateAlertValue, test.trigger, test.resolve)
+		})
+	}
 	testOneMinuteSystemAlert(t, "Memory", 50, setMemoryAlertValue, 51, 49)
 	testOneMinuteSystemAlert(t, "Disk", 50, setDiskAlertValue, 51, 49)
 	testOneMinuteSystemAlert(t, "Bandwidth", 50, setBandwidthAlertValue, [2]uint64{megabytesToBytes(26), megabytesToBytes(25)}, [2]uint64{megabytesToBytes(25), megabytesToBytes(24)})
@@ -204,6 +223,11 @@ func TestSystemAlertsOneMin(t *testing.T) {
 
 func TestSystemAlertsTwoMin(t *testing.T) {
 	testMultiMinuteSystemAlert(t, "CPU", 50, 2, setCPUAlertValue, 10, 51, 48)
+	for _, test := range cpuStateAlertTests {
+		t.Run(test.name, func(t *testing.T) {
+			testMultiMinuteSystemAlert(t, test.name, 50, 2, setCPUStateAlertValue, test.baseline, test.trigger, test.resolve)
+		})
+	}
 	testMultiMinuteSystemAlert(t, "Memory", 50, 2, setMemoryAlertValue, 10, 51, 48)
 	testMultiMinuteSystemAlert(t, "Disk", 50, 2, setDiskAlertValue, 10, 51, 48)
 	testMultiMinuteSystemAlert(t, "Bandwidth", 50, 2, setBandwidthAlertValue, [2]uint64{megabytesToBytes(10), megabytesToBytes(10)}, [2]uint64{megabytesToBytes(26), megabytesToBytes(25)}, [2]uint64{megabytesToBytes(10), megabytesToBytes(10)})
@@ -214,3 +238,17 @@ func TestSystemAlertsTwoMin(t *testing.T) {
 	testMultiMinuteSystemAlert(t, "LoadAvg15", 4, 2, setLoadAvgAlertValue, [3]float64{0, 0, 2}, [3]float64{0, 0, 4.1}, [3]float64{0, 0, 3.5})
 	testMultiMinuteSystemAlert(t, "Battery", 20, 2, setBatteryAlertValue, [2]uint8{21, 0}, [2]uint8{19, 0}, [2]uint8{25, 1})
 }
+
+func TestCPUStateAlertWithoutBreakdown(t *testing.T) {
+	fixture := newSystemAlertTestFixture(t, "CPUSteal", 1, 1)
+	defer fixture.cleanup()
+
+	synctest.Test(t, func(t *testing.T) {
+		submitValue(fixture, t, []float64(nil), setCPUStateAlertValue)
+		submitValue(fixture, t, []float64{0, 0, 0, 0, 0}, setCPUStateAlertValue)
+		waitForSystemAlert(time.Second)
+
+		fixture.assertTriggered(t, false, "Alert should ignore missing CPU breakdown data")
+		assert.Zero(t, fixture.hub.TestMailer.TotalSend(), "No email should be sent without CPU breakdown data")
+	})
+}

internal/alerts/alerts_systemd.go

@@ -0,0 +1,190 @@
+package alerts
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/henrygd/beszel/internal/entities/system"
+	"github.com/henrygd/beszel/internal/entities/systemd"
+
+	"github.com/pocketbase/dbx"
+	"github.com/pocketbase/pocketbase/core"
+)
+
+// alertNameSystemdFailed is the alerts.name value for the failed systemd services alert.
+const alertNameSystemdFailed = "SystemdFailed"
+
+// maxListedServices caps how many service names are listed in a notification body.
+const maxListedServices = 10
+
+// HandleSystemdAlerts manages alerts for systemd services in the failed state.
+//
+// This is a binary state alert and fires on the first observation of a failed
+// service rather than using a delay. The agent only refreshes systemd state every
+// 10 minutes, so a shorter delay could never observe new data before expiring, and
+// that poll interval already hides services that fail and restart quickly.
+func (am *AlertManager) HandleSystemdAlerts(systemRecord *core.Record) error {
+	alerts := am.alertsCache.GetAlertsByName(systemRecord.Id, alertNameSystemdFailed)
+	if len(alerts) == 0 {
+		return nil
+	}
+
+	// State is read from the systemd_services snapshot rather than the update payload.
+	// The payload is not a reliable source here: realtime dashboard subscriptions fetch
+	// from the agent with a shorter cache time, and the agent omits systemd services from
+	// those responses, overwriting the cached payload roughly once a second while a system
+	// is being viewed. The snapshot table is only written by the full update cycle.
+	total, failed, err := am.queryServiceStates(systemRecord.Id)
+	if err != nil {
+		return err
+	}
+	if total == 0 {
+		// No rows normally means no systemd data for this system (agent without
+		// systemd, or not yet reported), which must not be treated as a recovery.
+		// Read info only in this ambiguous case. The record being saved is used
+		// instead of data because dashboard polling can replace the system's
+		// in-memory payload concurrently.
+		var currentInfo system.Info
+		if err := systemRecord.UnmarshalJSONField("info", &currentInfo); err != nil ||
+			len(currentInfo.Services) == 0 || currentInfo.Services[0] != 0 {
+			return nil
+		}
+	}
+
+	systemName := systemRecord.GetString("name")
+
+	for _, alertData := range alerts {
+		triggered := len(failed) > 0
+		// Only notify on a change of state, so a service that stays failed across
+		// cycles doesn't re-notify every update.
+		if triggered == alertData.Triggered {
+			continue
+		}
+		if err := am.sendSystemdAlert(triggered, systemName, alertData, failed); err != nil {
+			am.hub.Logger().Error("Failed to send alert", "err", err)
+		}
+	}
+	return nil
+}
+
+// queryServiceStates returns the number of services reported in the most recent update
+// for a system, and the names of those in the failed state.
+//
+// Rows are restricted to the latest update because systemd_services is upserted, never
+// pruned on change: a service that no longer exists on the host stops being reported and
+// its row keeps its last known state until the retention sweep removes it. Every row
+// written in one cycle shares a single updated timestamp, so the newest timestamp
+// identifies exactly the services the agent last reported.
+func (am *AlertManager) queryServiceStates(systemID string) (total int, failed []string, err error) {
+	var rows []struct {
+		Name  string               `db:"name"`
+		State systemd.ServiceState `db:"state"`
+	}
+	err = am.hub.DB().
+		Select("name", "state").
+		From("systemd_services").
+		Where(dbx.NewExp(
+			"system={:system} AND updated=(SELECT MAX(updated) FROM systemd_services WHERE system={:system})",
+			dbx.Params{"system": systemID},
+		)).
+		OrderBy("name").
+		All(&rows)
+	if err != nil {
+		return 0, nil, err
+	}
+	for _, row := range rows {
+		if row.State == systemd.StatusFailed {
+			failed = append(failed, row.Name)
+		}
+	}
+	return len(rows), failed, nil
+}
+
+// sendSystemdAlert sends a failed or recovered systemd services alert to the alert's user.
+func (am *AlertManager) sendSystemdAlert(triggered bool, systemName string, alertData CachedAlertData, failed []string) error {
+	// Update trigger state for alert record before sending alert
+	if err := am.setAlertTriggered(alertData, triggered); err != nil {
+		return err
+	}
+
+	var title, message string
+	if triggered {
+		title = fmt.Sprintf("Failed services on %s %v", systemName, "\U0001F534") // Red alert emoji
+		message = fmt.Sprintf("%s on %s: %s", pluralizeServices(len(failed)), systemName, formatServiceList(failed))
+	} else {
+		title = fmt.Sprintf("Services recovered on %s %v", systemName, "✅") // Green checkmark emoji
+		message = fmt.Sprintf("No services are in the failed state on %s.", systemName)
+	}
+
+	systemID := alertData.SystemID
+
+	return am.SendAlert(AlertMessageData{
+		UserID:   alertData.UserID,
+		SystemID: systemID,
+		Title:    title,
+		Message:  message,
+		Link:     am.hub.MakeLink("system", systemID),
+		LinkText: "View " + systemName,
+	})
+}
+
+// pluralizeServices returns a count label like "1 failed service" or "3 failed services".
+func pluralizeServices(count int) string {
+	if count == 1 {
+		return "1 failed service"
+	}
+	return fmt.Sprintf("%d failed services", count)
+}
+
+// formatServiceList joins service names, truncating long lists.
+func formatServiceList(names []string) string {
+	if len(names) <= maxListedServices {
+		return strings.Join(names, ", ")
+	}
+	remaining := len(names) - maxListedServices
+	return fmt.Sprintf("%s and %d more", strings.Join(names[:maxListedServices], ", "), remaining)
+}
+
+// resolveSystemdAlerts resolves triggered systemd alerts for systems that no longer
+// have any failed services. This clears stale state left by a hub restart.
+func resolveSystemdAlerts(app core.App) error {
+	db := app.DB()
+	var alertIds []string
+	err := db.NewQuery(`
+		SELECT a.id
+		FROM alerts a
+		JOIN systems sys ON sys.id = a.system
+		WHERE a.name = {:name}
+		AND a.triggered = true
+		AND (
+			EXISTS (
+				SELECT 1 FROM systemd_services cur
+				WHERE cur.system = a.system
+				AND cur.updated = (SELECT MAX(updated) FROM systemd_services WHERE system = a.system)
+			)
+			OR json_extract(sys.info, '$.sv[0]') = 0
+		)
+		AND NOT EXISTS (
+			SELECT 1 FROM systemd_services s
+			WHERE s.system = a.system AND s.state = {:state}
+			AND s.updated = (SELECT MAX(updated) FROM systemd_services WHERE system = a.system)
+		)
+	`).Bind(dbx.Params{
+		"name":  alertNameSystemdFailed,
+		"state": systemd.StatusFailed,
+	}).Column(&alertIds)
+	if err != nil {
+		return err
+	}
+	for _, alertId := range alertIds {
+		alert, err := app.FindRecordById("alerts", alertId)
+		if err != nil {
+			return err
+		}
+		alert.Set("triggered", false)
+		if err := app.Save(alert); err != nil {
+			return err
+		}
+	}
+	return nil
+}

internal/alerts/alerts_systemd_test.go

@@ -0,0 +1,383 @@
+//go:build testing
+
+package alerts_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/henrygd/beszel/internal/alerts"
+	systemEntity "github.com/henrygd/beszel/internal/entities/system"
+	"github.com/henrygd/beszel/internal/entities/systemd"
+	beszelTests "github.com/henrygd/beszel/internal/tests"
+	"github.com/pocketbase/dbx"
+	"github.com/pocketbase/pocketbase/core"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// setSystemdServiceState upserts a systemd_services row mirroring the raw SQL write
+// path used by the hub (createSystemdStatsRecords), which bypasses record hooks.
+func setSystemdServiceState(t *testing.T, hub core.App, systemID, name string, state systemd.ServiceState, updated int64) {
+	t.Helper()
+
+	_, err := hub.DB().NewQuery(
+		"INSERT INTO systemd_services (id, system, name, state, sub, cpu, cpuPeak, memory, memPeak, updated) " +
+			"VALUES ({:id}, {:system}, {:name}, {:state}, 0, 0, 0, 0, 0, {:updated}) " +
+			"ON CONFLICT(id) DO UPDATE SET state = excluded.state, updated = excluded.updated",
+	).Bind(dbx.Params{
+		"id":      systemID + "-" + name,
+		"system":  systemID,
+		"name":    name,
+		"state":   state,
+		"updated": updated,
+	}).Execute()
+	require.NoError(t, err)
+}
+
+// seedServices writes a set of services into the systemd_services snapshot, which is the
+// source HandleSystemdAlerts reads from. All rows share one updated timestamp, matching
+// how the hub writes a batch in createSystemdStatsRecords.
+func seedServices(t *testing.T, hub core.App, systemID string, states ...systemd.ServiceState) {
+	t.Helper()
+	seedServicesAt(t, hub, systemID, time.Now().UTC().UnixMilli(), states...)
+}
+
+// seedServicesAt writes services with an explicit batch timestamp.
+func seedServicesAt(t *testing.T, hub core.App, systemID string, updated int64, states ...systemd.ServiceState) {
+	t.Helper()
+	for i, state := range states {
+		setSystemdServiceState(t, hub, systemID, serviceName(i), state, updated)
+	}
+}
+
+func serviceName(i int) string {
+	return string(rune('a'+i)) + ".service"
+}
+
+// systemdTestSetup creates a user with an email, a system, and a SystemdFailed alert.
+func systemdTestSetup(t *testing.T, triggered bool) (*beszelTests.TestHub, *core.Record, *core.Record) {
+	t.Helper()
+
+	hub, user := beszelTests.GetHubWithUser(t)
+
+	userSettings, err := hub.FindFirstRecordByFilter("user_settings", "user={:user}", map[string]any{"user": user.Id})
+	require.NoError(t, err)
+	userSettings.Set("settings", `{"emails":["test@example.com"],"webhooks":[]}`)
+	require.NoError(t, hub.Save(userSettings))
+
+	// "paused" avoids spawning a background updater goroutine that would outlive
+	// the test hub; these tests drive HandleSystemdAlerts directly.
+	systems, err := beszelTests.CreateSystems(hub, 1, user.Id, "paused")
+	require.NoError(t, err)
+	system := systems[0]
+
+	alert, err := beszelTests.CreateRecord(hub, "alerts", map[string]any{
+		"name":      "SystemdFailed",
+		"system":    system.Id,
+		"user":      user.Id,
+		"triggered": triggered,
+	})
+	require.NoError(t, err)
+
+	return hub, system, alert
+}
+
+func TestSystemdAlertFiresImmediately(t *testing.T) {
+	hub, system, alert := systemdTestSetup(t, false)
+	defer hub.Cleanup()
+
+	initialEmailCount := hub.TestMailer.TotalSend()
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+
+	seedServices(t, hub, system.Id, systemd.StatusFailed, systemd.StatusActive)
+	require.NoError(t, am.HandleSystemdAlerts(system))
+
+	assert.Equal(t, initialEmailCount+1, hub.TestMailer.TotalSend(), "failed service should notify on first observation")
+
+	messages := hub.TestMailer.Messages()
+	require.NotEmpty(t, messages)
+	last := messages[len(messages)-1]
+	assert.Contains(t, last.Subject, "Failed services")
+	assert.Contains(t, last.Text, "a.service", "notification should name the failed service")
+
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.True(t, alertRecord.GetBool("triggered"), "alert should be marked triggered")
+
+	// history record should be created via the alerts update hook
+	historyCount, err := hub.CountRecords("alerts_history", dbx.HashExp{"resolved": ""})
+	require.NoError(t, err)
+	assert.EqualValues(t, 1, historyCount, "should have one unresolved alert history record")
+}
+
+func TestSystemdAlertFullCycle(t *testing.T) {
+	hub, system, alert := systemdTestSetup(t, false)
+	defer hub.Cleanup()
+
+	initialEmailCount := hub.TestMailer.TotalSend()
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+
+	// Fail, then recover.
+	seedServices(t, hub, system.Id, systemd.StatusFailed)
+	require.NoError(t, am.HandleSystemdAlerts(system))
+	seedServices(t, hub, system.Id, systemd.StatusActive)
+	require.NoError(t, am.HandleSystemdAlerts(system))
+
+	assert.Equal(t, initialEmailCount+2, hub.TestMailer.TotalSend(), "should send a failure and a recovery notification")
+
+	messages := hub.TestMailer.Messages()
+	require.Len(t, messages, 2)
+	assert.Contains(t, messages[0].Subject, "Failed services")
+	assert.Contains(t, messages[1].Subject, "Services recovered")
+
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.False(t, alertRecord.GetBool("triggered"), "alert should be cleared after recovery")
+
+	// history record should be resolved
+	historyCount, err := hub.CountRecords("alerts_history", dbx.HashExp{"resolved": ""})
+	require.NoError(t, err)
+	assert.Zero(t, historyCount, "alert history record should be resolved")
+}
+
+func TestSystemdAlertSendsRecoveryWhenTriggered(t *testing.T) {
+	hub, system, alert := systemdTestSetup(t, true)
+	defer hub.Cleanup()
+
+	initialEmailCount := hub.TestMailer.TotalSend()
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+
+	seedServices(t, hub, system.Id, systemd.StatusActive, systemd.StatusInactive)
+	require.NoError(t, am.HandleSystemdAlerts(system))
+
+	assert.Equal(t, initialEmailCount+1, hub.TestMailer.TotalSend(), "recovery notification should be sent")
+	messages := hub.TestMailer.Messages()
+	require.NotEmpty(t, messages)
+	assert.Contains(t, messages[len(messages)-1].Subject, "Services recovered")
+
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.False(t, alertRecord.GetBool("triggered"), "alert should be cleared after recovery")
+}
+
+func TestSystemdAlertDoesNotResendWhileTriggered(t *testing.T) {
+	hub, system, _ := systemdTestSetup(t, true)
+	defer hub.Cleanup()
+
+	initialEmailCount := hub.TestMailer.TotalSend()
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+
+	// Still failing across several cycles — should not re-notify.
+	for range 3 {
+		seedServices(t, hub, system.Id, systemd.StatusFailed)
+		require.NoError(t, am.HandleSystemdAlerts(system))
+	}
+
+	assert.Equal(t, initialEmailCount, hub.TestMailer.TotalSend(), "should not re-notify while still triggered")
+}
+
+func TestSystemdAlertRepeatedFailureNotifiesOnce(t *testing.T) {
+	hub, system, _ := systemdTestSetup(t, false)
+	defer hub.Cleanup()
+
+	initialEmailCount := hub.TestMailer.TotalSend()
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+
+	for range 3 {
+		seedServices(t, hub, system.Id, systemd.StatusFailed)
+		require.NoError(t, am.HandleSystemdAlerts(system))
+	}
+
+	assert.Equal(t, initialEmailCount+1, hub.TestMailer.TotalSend(), "repeated failures should only notify once")
+}
+
+// A service that no longer exists on the host stops being reported, but its row stays
+// in systemd_services with its last known state until the retention sweep. That stale
+// row must not keep the alert triggered.
+func TestSystemdAlertIgnoresServicesNoLongerReported(t *testing.T) {
+	hub, system, alert := systemdTestSetup(t, true)
+	defer hub.Cleanup()
+
+	initialEmailCount := hub.TestMailer.TotalSend()
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+
+	now := time.Now().UTC().UnixMilli()
+	// Older batch still holding a failed service that has since been removed.
+	setSystemdServiceState(t, hub, system.Id, "gone.service", systemd.StatusFailed, now-60_000)
+	// Current batch reports only healthy services.
+	seedServicesAt(t, hub, system.Id, now, systemd.StatusActive, systemd.StatusActive)
+
+	require.NoError(t, am.HandleSystemdAlerts(system))
+
+	assert.Equal(t, initialEmailCount+1, hub.TestMailer.TotalSend(), "stale failed row should not block recovery")
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.False(t, alertRecord.GetBool("triggered"), "alert should resolve once the service stops being reported")
+}
+
+func TestResolveSystemdAlertsIgnoresStaleFailedRows(t *testing.T) {
+	hub, system, alert := systemdTestSetup(t, true)
+	defer hub.Cleanup()
+
+	now := time.Now().UTC().UnixMilli()
+	setSystemdServiceState(t, hub, system.Id, "gone.service", systemd.StatusFailed, now-60_000)
+	seedServicesAt(t, hub, system.Id, now, systemd.StatusActive)
+
+	require.NoError(t, alerts.ResolveSystemdAlerts(hub))
+
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.False(t, alertRecord.GetBool("triggered"), "stale failed row should not keep the alert triggered")
+}
+
+func TestSystemdAlertNoSystemdDataIsIgnored(t *testing.T) {
+	hub, system, alert := systemdTestSetup(t, true)
+	defer hub.Cleanup()
+
+	initialEmailCount := hub.TestMailer.TotalSend()
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+
+	// A system with no systemd_services rows (agent without systemd, or nothing
+	// reported yet) must not be treated as a recovery.
+	require.NoError(t, am.HandleSystemdAlerts(system))
+	require.NoError(t, am.HandleSystemdAlerts(system))
+
+	assert.Equal(t, initialEmailCount, hub.TestMailer.TotalSend(), "missing systemd data should not send a recovery")
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.True(t, alertRecord.GetBool("triggered"), "triggered state should be preserved when data is absent")
+}
+
+func TestSystemdAlertFreshEmptySnapshotResolves(t *testing.T) {
+	hub, system, alert := systemdTestSetup(t, true)
+	defer hub.Cleanup()
+
+	initialEmailCount := hub.TestMailer.TotalSend()
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+
+	// An explicit zero service count on the saved system record distinguishes a
+	// confirmed empty snapshot from an agent response that omitted systemd data.
+	system.Set("info", systemEntity.Info{Services: []uint16{0, 0}})
+	require.NoError(t, am.HandleSystemAlerts(system, nil))
+
+	assert.Equal(t, initialEmailCount+1, hub.TestMailer.TotalSend(), "fresh empty snapshot should send a recovery")
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.False(t, alertRecord.GetBool("triggered"), "fresh empty snapshot should resolve the alert")
+}
+
+func TestSystemdAlertNoAlertRecord(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	systems, err := beszelTests.CreateSystems(hub, 1, user.Id, "paused")
+	require.NoError(t, err)
+	system := systems[0]
+
+	initialEmailCount := hub.TestMailer.TotalSend()
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+
+	seedServices(t, hub, system.Id, systemd.StatusFailed)
+	require.NoError(t, am.HandleSystemdAlerts(system))
+	assert.Equal(t, initialEmailCount, hub.TestMailer.TotalSend(), "no email when no alert record exists")
+}
+
+func TestResolveSystemdAlertsClearsStaleTriggered(t *testing.T) {
+	hub, system, alert := systemdTestSetup(t, true)
+	defer hub.Cleanup()
+
+	// No failed services in the snapshot, but the alert is still marked triggered
+	// (e.g. the hub restarted while the alert was active).
+	setSystemdServiceState(t, hub, system.Id, "a.service", systemd.StatusActive, time.Now().UTC().UnixMilli())
+
+	require.NoError(t, alerts.ResolveSystemdAlerts(hub))
+
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.False(t, alertRecord.GetBool("triggered"), "stale triggered flag should be cleared")
+}
+
+func TestResolveSystemdAlertsKeepsTriggeredWithoutSystemdData(t *testing.T) {
+	hub, _, alert := systemdTestSetup(t, true)
+	defer hub.Cleanup()
+
+	// Missing rows do not prove recovery. This can happen when a system is offline
+	// and its last service snapshot has been removed by retention.
+	require.NoError(t, alerts.ResolveSystemdAlerts(hub))
+
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.True(t, alertRecord.GetBool("triggered"), "missing systemd data should preserve triggered state")
+}
+
+func TestResolveSystemdAlertsClearsConfirmedEmptySnapshot(t *testing.T) {
+	hub, system, alert := systemdTestSetup(t, true)
+	defer hub.Cleanup()
+
+	// Update the persisted snapshot directly so record hooks don't alter alert state
+	// before the startup resolver is exercised.
+	_, err := hub.DB().NewQuery(
+		"UPDATE systems SET info = {:info} WHERE id = {:id}",
+	).Bind(dbx.Params{"info": `{"sv":[0,0]}`, "id": system.Id}).Execute()
+	require.NoError(t, err)
+	require.NoError(t, alerts.ResolveSystemdAlerts(hub))
+
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.False(t, alertRecord.GetBool("triggered"), "confirmed empty snapshot should clear triggered state")
+}
+
+func TestResolveSystemdAlertsKeepsStillFailing(t *testing.T) {
+	hub, system, alert := systemdTestSetup(t, true)
+	defer hub.Cleanup()
+
+	setSystemdServiceState(t, hub, system.Id, "a.service", systemd.StatusFailed, time.Now().UTC().UnixMilli())
+
+	require.NoError(t, alerts.ResolveSystemdAlerts(hub))
+
+	alertRecord, err := hub.FindRecordById("alerts", alert.Id)
+	require.NoError(t, err)
+	assert.True(t, alertRecord.GetBool("triggered"), "alert should stay triggered while a service is still failed")
+}
+
+func TestSystemdAlertMultipleUsersRespectOwnAlerts(t *testing.T) {
+	hub, user1 := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	setStatusAlertEmail(t, hub, user1.Id, "user1@example.com")
+
+	user2, err := beszelTests.CreateUser(hub, "user2@example.com", "password")
+	require.NoError(t, err)
+	_, err = beszelTests.CreateRecord(hub, "user_settings", map[string]any{
+		"user": user2.Id,
+		"settings": map[string]any{
+			"emails":   []string{"user2@example.com"},
+			"webhooks": []string{},
+		},
+	})
+	require.NoError(t, err)
+
+	system, err := beszelTests.CreateRecord(hub, "systems", map[string]any{
+		"name":  "shared-system",
+		"users": []string{user1.Id, user2.Id},
+		"host":  "127.0.0.1",
+	})
+	require.NoError(t, err)
+
+	for _, user := range []*core.Record{user1, user2} {
+		_, err = beszelTests.CreateRecord(hub, "alerts", map[string]any{
+			"name":   "SystemdFailed",
+			"system": system.Id,
+			"user":   user.Id,
+		})
+		require.NoError(t, err)
+	}
+
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+	seedServices(t, hub, system.Id, systemd.StatusFailed)
+	require.NoError(t, am.HandleSystemdAlerts(system))
+
+	messages := hub.TestMailer.Messages()
+	require.Len(t, messages, 2, "each user should receive their own alert")
+}

internal/alerts/alerts_test_helpers.go

@@ -88,6 +88,10 @@ func ResolveStatusAlerts(app core.App) error {
 	return resolveStatusAlerts(app)
 }
 
+func ResolveSystemdAlerts(app core.App) error {
+	return resolveSystemdAlerts(app)
+}
+
 func (am *AlertManager) RestorePendingStatusAlerts() error {
 	return am.restorePendingStatusAlerts()
 }
@@ -96,6 +100,7 @@ func (am *AlertManager) SetAlertTriggered(alert CachedAlertData, triggered bool)
 	return am.setAlertTriggered(alert, triggered)
 }
 
-func IsInternalURL(rawURL string) (bool, error) {
+// BuildContainerLogExcerpt exposes buildContainerLogExcerpt for testing.
-	return isInternalURL(rawURL)
+func BuildContainerLogExcerpt(raw string) string {
+	return buildContainerLogExcerpt(raw)
 }

internal/alerts/alerts_webhooks_test.go

@@ -0,0 +1,66 @@
+//go:build testing
+
+package alerts_test
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"sync/atomic"
+	"testing"
+
+	"github.com/henrygd/beszel/internal/alerts"
+	beszelTests "github.com/henrygd/beszel/internal/tests"
+	"github.com/pocketbase/dbx"
+	"github.com/stretchr/testify/require"
+)
+
+func TestPersistedWebhooksUseCurrentOwnerRole(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+	am := alerts.NewTestAlertManagerWithoutWorker(hub)
+
+	var delivered atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		delivered.Add(1)
+	}))
+	defer server.Close()
+
+	settings, err := hub.FindFirstRecordByFilter("user_settings", "user={:user}", dbx.Params{"user": user.Id})
+	require.NoError(t, err)
+	settings.Set("settings", alerts.UserNotificationSettings{Webhooks: []string{"generic+" + server.URL}})
+	require.NoError(t, hub.Save(settings))
+	message := alerts.AlertMessageData{UserID: user.Id, Title: "Test", Message: "Persisted webhook"}
+
+	// Keep the same URL and manager while changing roles, so cached privileges
+	// or treating previously saved URLs as trusted would fail this test.
+	for _, tc := range []struct {
+		name string
+		role string
+		want int32
+	}{
+		{"regular user", "user", 0},
+		{"readonly user", "readonly", 0},
+		{"promoted admin", "admin", 1},
+		{"demoted admin", "user", 1},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			user.Set("role", tc.role)
+			require.NoError(t, hub.Save(user))
+			// Webhook errors are logged; SendAlert continues to email delivery.
+			require.NoError(t, am.SendAlert(message))
+			require.Equal(t, tc.want, delivered.Load())
+		})
+	}
+
+	t.Run("missing owner fails closed", func(t *testing.T) {
+		// Model an orphaned settings record without deleting it through the
+		// normal user deletion cascade.
+		const missingOwner = "missingowner123"
+		settings.Set("user", missingOwner)
+		require.NoError(t, hub.SaveNoValidate(settings))
+		message.UserID = missingOwner
+		err := am.SendAlert(message)
+		require.ErrorContains(t, err, "load notification owner")
+		require.EqualValues(t, 1, delivered.Load())
+	})
+}

internal/alerts/alerts_zfs.go

@@ -0,0 +1,145 @@
+package alerts
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/pocketbase/dbx"
+	"github.com/pocketbase/pocketbase/core"
+)
+
+// handleZfsPoolAlert sends alerts when a ZFS pool health state worsens and
+// resolves the alert history entry when the pool recovers. Like the SMART
+// hook, this is automatic and does not require user opt-in.
+func (am *AlertManager) handleZfsPoolAlert(e *core.RecordEvent) error {
+	return am.handleZfsPoolHealthAlert(e, e.Record.Original().GetString("health"))
+}
+
+func (am *AlertManager) handleZfsPoolCreateAlert(e *core.RecordEvent) error {
+	return am.handleZfsPoolHealthAlert(e, "")
+}
+
+func (am *AlertManager) handleZfsPoolHealthAlert(e *core.RecordEvent, oldHealth string) error {
+	newHealth := e.Record.GetString("health")
+	oldSeverity := zfsPoolSeverity(oldHealth)
+	newSeverity := zfsPoolSeverity(newHealth)
+
+	systemID := e.Record.GetString("system")
+	if systemID == "" {
+		return e.Next()
+	}
+
+	systemRecord, err := e.App.FindRecordById("systems", systemID)
+	if err != nil {
+		e.App.Logger().Error("Failed to find system for ZFS alert", "err", err, "systemID", systemID)
+		return e.Next()
+	}
+
+	// Pool recovered to a healthy state: resolve any open history entries.
+	if newSeverity == 1 && oldSeverity > 1 {
+		resolveAllAlertHistoryRecords(e.App, e.Record.Id)
+		return e.Next()
+	}
+
+	if !shouldSendZfsPoolAlert(oldSeverity, newSeverity) {
+		return e.Next()
+	}
+
+	systemName := systemRecord.GetString("name")
+	poolName := e.Record.GetString("display_name")
+	if poolName == "" {
+		poolName = e.Record.GetString("name")
+	}
+
+	title := fmt.Sprintf("Storage pool %s on %s: %s", newHealth, systemName, poolName)
+	message := fmt.Sprintf("Storage pool %s (%s) was first observed as %s", poolName, systemName, newHealth)
+	if oldSeverity > 0 {
+		message = fmt.Sprintf("Storage pool %s (%s) health changed from %s to %s", poolName, systemName, oldHealth, newHealth)
+	}
+
+	userIDs := systemRecord.GetStringSlice("users")
+	if len(userIDs) == 0 {
+		return e.Next()
+	}
+
+	for _, userID := range userIDs {
+		if err := am.SendAlert(AlertMessageData{
+			UserID:   userID,
+			SystemID: systemID,
+			Title:    title,
+			Message:  message,
+			Link:     am.hub.MakeLink("system", systemID),
+			LinkText: "View " + systemName,
+		}); err != nil {
+			e.App.Logger().Error("Failed to send ZFS alert", "err", err, "userID", userID)
+		}
+		_ = createZfsPoolHistoryRecord(e.App, userID, systemID, e.Record.Id, poolName)
+	}
+
+	return e.Next()
+}
+
+// resolveZfsPoolHistoryOnDelete resolves open alert history entries when a
+// pool record is deleted (manually or because the pool disappeared), so the
+// UI does not keep showing an ongoing alert for a pool that no longer exists.
+func resolveZfsPoolHistoryOnDelete(e *core.RecordEvent) error {
+	resolveAllAlertHistoryRecords(e.App, e.Record.Id)
+	return e.Next()
+}
+
+// shouldSendZfsPoolAlert reports whether a health transition warrants an alert.
+// First observations of unhealthy pools and worsening transitions are reported.
+func shouldSendZfsPoolAlert(oldSeverity, newSeverity int) bool {
+	return newSeverity > 1 && (oldSeverity == 0 || newSeverity > oldSeverity)
+}
+
+// zfsPoolSeverity ranks pool health states: healthy (1), degraded (2),
+// failed/unavailable (3), unknown (0).
+func zfsPoolSeverity(health string) int {
+	switch health {
+	case "ONLINE":
+		return 1
+	case "DEGRADED":
+		return 2
+	case "FAULTED", "OFFLINE", "UNAVAIL", "REMOVED", "SUSPENDED":
+		return 3
+	default:
+		return 0
+	}
+}
+
+// createZfsPoolHistoryRecord logs a pool health alert in the alerts history so
+// it is visible in the UI without creating an editable alert configuration.
+func createZfsPoolHistoryRecord(app core.App, userID, systemID, alertID, poolName string) error {
+	collection, err := app.FindCachedCollectionByNameOrId("alerts_history")
+	if err != nil {
+		return err
+	}
+	record := core.NewRecord(collection)
+	record.Set("user", userID)
+	record.Set("system", systemID)
+	record.Set("alert_id", alertID)
+	record.Set("name", "Storage Pool: "+poolName)
+	return app.Save(record)
+}
+
+// resolveAllAlertHistoryRecords resolves every open history entry for an alert
+// record id (one per system user).
+func resolveAllAlertHistoryRecords(app core.App, alertID string) {
+	records, err := app.FindRecordsByFilter(
+		"alerts_history",
+		"alert_id={:alert_id} && resolved=null",
+		"", 0, 0,
+		dbx.Params{"alert_id": alertID},
+	)
+	if err != nil || len(records) == 0 {
+		return
+	}
+	now := time.Now().UTC()
+	for _, record := range records {
+		record.Set("resolved", now)
+		if err := app.Save(record); err != nil {
+			app.Logger().Error("Failed to resolve ZFS alert history", "err", err, "recordId", record.Id)
+		}
+	}
+}

internal/alerts/alerts_zfs_disk_test.go

@@ -0,0 +1,179 @@
+//go:build testing
+
+package alerts_test
+
+import (
+	"encoding/json"
+	"testing"
+	"time"
+
+	"github.com/henrygd/beszel/internal/entities/system"
+	beszelTests "github.com/henrygd/beszel/internal/tests"
+
+	"github.com/pocketbase/dbx"
+	"github.com/pocketbase/pocketbase/tools/types"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestDiskAlertZfsPoolMultiMinute verifies that ZFS pool usage participates in
+// the Disk threshold alert using historical per-minute values, mirroring the
+// extra-filesystem behavior.
+func TestDiskAlertZfsPoolMultiMinute(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	systems, err := beszelTests.CreateSystems(hub, 1, user.Id, "up")
+	require.NoError(t, err)
+	systemRecord := systems[0]
+
+	diskAlert, err := beszelTests.CreateRecord(hub, "alerts", map[string]any{
+		"name":   "Disk",
+		"system": systemRecord.Id,
+		"user":   user.Id,
+		"value":  80, // threshold: 80%
+		"min":    2,  // requires historical averaging
+	})
+	require.NoError(t, err)
+
+	am := hub.GetAlertManager()
+	now := time.Now().UTC()
+
+	poolHigh := map[string]*system.ZfsPool{
+		"tank": {Total: 1000, Used: 920}, // 92% - above threshold
+	}
+
+	recordTimes := []time.Duration{
+		-180 * time.Second,
+		-90 * time.Second,
+		-60 * time.Second,
+		-30 * time.Second,
+	}
+
+	for _, offset := range recordTimes {
+		stats := system.Stats{
+			DiskPct:  30, // root disk at 30% - below threshold
+			ZfsPools: poolHigh,
+		}
+		statsJSON, _ := json.Marshal(stats)
+
+		recordTime := now.Add(offset)
+		record, err := beszelTests.CreateRecord(hub, "system_stats", map[string]any{
+			"system": systemRecord.Id,
+			"type":   "1m",
+			"stats":  string(statsJSON),
+		})
+		require.NoError(t, err)
+		record.SetRaw("created", recordTime.Format(types.DefaultDateLayout))
+		err = hub.SaveNoValidate(record)
+		require.NoError(t, err)
+	}
+
+	combinedDataHigh := &system.CombinedData{
+		Stats: system.Stats{
+			DiskPct:  30,
+			ZfsPools: poolHigh,
+		},
+		Info: system.Info{
+			DiskPct: 30,
+		},
+	}
+
+	systemRecord.Set("updated", now)
+	err = hub.SaveNoValidate(systemRecord)
+	require.NoError(t, err)
+
+	err = am.HandleSystemAlerts(systemRecord, combinedDataHigh)
+	require.NoError(t, err)
+
+	time.Sleep(20 * time.Millisecond)
+
+	diskAlert, err = hub.FindFirstRecordByFilter("alerts", "id={:id}", dbx.Params{"id": diskAlert.Id})
+	require.NoError(t, err)
+	assert.True(t, diskAlert.GetBool("triggered"),
+		"Alert should be triggered when ZFS pool average (92%%) exceeds threshold (80%%)")
+
+	// --- Resolution: pool drops to 50%, alert should resolve ---
+
+	poolLow := map[string]*system.ZfsPool{
+		"tank": {Total: 1000, Used: 500}, // 50% - below threshold
+	}
+
+	newNow := now.Add(2 * time.Minute)
+	for _, offset := range recordTimes {
+		stats := system.Stats{
+			DiskPct:  30,
+			ZfsPools: poolLow,
+		}
+		statsJSON, _ := json.Marshal(stats)
+
+		recordTime := newNow.Add(offset)
+		record, err := beszelTests.CreateRecord(hub, "system_stats", map[string]any{
+			"system": systemRecord.Id,
+			"type":   "1m",
+			"stats":  string(statsJSON),
+		})
+		require.NoError(t, err)
+		record.SetRaw("created", recordTime.Format(types.DefaultDateLayout))
+		err = hub.SaveNoValidate(record)
+		require.NoError(t, err)
+	}
+
+	combinedDataLow := &system.CombinedData{
+		Stats: system.Stats{
+			DiskPct:  30,
+			ZfsPools: poolLow,
+		},
+		Info: system.Info{
+			DiskPct: 30,
+		},
+	}
+
+	systemRecord.Set("updated", newNow)
+	err = hub.SaveNoValidate(systemRecord)
+	require.NoError(t, err)
+
+	err = am.HandleSystemAlerts(systemRecord, combinedDataLow)
+	require.NoError(t, err)
+
+	time.Sleep(20 * time.Millisecond)
+
+	diskAlert, err = hub.FindFirstRecordByFilter("alerts", "id={:id}", dbx.Params{"id": diskAlert.Id})
+	require.NoError(t, err)
+	assert.False(t, diskAlert.GetBool("triggered"),
+		"Alert should be resolved when ZFS pool average (50%%) drops below threshold (80%%)")
+}
+
+func TestDiskAlertIgnoresRawPool(t *testing.T) {
+	for _, minutes := range []int{0, 2} {
+		hub, user := beszelTests.GetHubWithUser(t)
+		systems, err := beszelTests.CreateSystems(hub, 1, user.Id, "up")
+		require.NoError(t, err)
+		alert, err := beszelTests.CreateRecord(hub, "alerts", map[string]any{"name": "Disk", "system": systems[0].Id, "user": user.Id, "value": 80, "min": minutes})
+		require.NoError(t, err)
+		pools := map[string]*system.ZfsPool{"btrfs": {Total: 100, Used: 99, Raw: true}}
+		for _, offset := range []time.Duration{-180, -90, -60, -30} {
+			data, err := json.Marshal(system.Stats{ZfsPools: pools})
+			require.NoError(t, err)
+			record, err := beszelTests.CreateRecord(hub, "system_stats", map[string]any{"system": systems[0].Id, "type": "1m", "stats": string(data)})
+			require.NoError(t, err)
+			record.SetRaw("created", time.Now().UTC().Add(offset*time.Second).Format(types.DefaultDateLayout))
+			require.NoError(t, hub.SaveNoValidate(record))
+		}
+		require.NoError(t, hub.GetAlertManager().HandleSystemAlerts(systems[0], &system.CombinedData{Stats: system.Stats{ZfsPools: pools}}))
+		time.Sleep(20 * time.Millisecond)
+		record, err := hub.FindRecordById("alerts", alert.Id)
+		require.NoError(t, err)
+		assert.False(t, record.GetBool("triggered"))
+		if minutes > 0 {
+			// A current usable sample must not make raw historical values eligible.
+			pools["btrfs"].Raw = false
+			require.NoError(t, hub.GetAlertManager().HandleSystemAlerts(systems[0], &system.CombinedData{Stats: system.Stats{ZfsPools: pools}}))
+			time.Sleep(20 * time.Millisecond)
+			record, err = hub.FindRecordById("alerts", alert.Id)
+			require.NoError(t, err)
+			assert.False(t, record.GetBool("triggered"))
+		}
+		hub.Cleanup()
+	}
+}

internal/alerts/alerts_zfs_key_test.go

@@ -0,0 +1,15 @@
+//go:build testing
+
+package alerts
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestZfsDiskAlertKeyIsNamespaced(t *testing.T) {
+	assert.Equal(t, "zfs:tank", zfsDiskAlertKey("tank"))
+	assert.Equal(t, "Usage of storage pool tank", diskAlertDescriptor(zfsDiskAlertKey("tank")))
+	assert.Equal(t, "Usage of tank", diskAlertDescriptor("tank"))
+}

internal/alerts/alerts_zfs_test.go

@@ -0,0 +1,292 @@
+//go:build testing
+
+package alerts_test
+
+import (
+	"testing"
+	"time"
+
+	beszelTests "github.com/henrygd/beszel/internal/tests"
+	"github.com/pocketbase/pocketbase/core"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestZfsPoolAlertOnlineToDegraded(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	system, err := beszelTests.CreateRecord(hub, "systems", map[string]any{
+		"name":  "test-system",
+		"users": []string{user.Id},
+		"host":  "127.0.0.1",
+	})
+	assert.NoError(t, err)
+
+	pool, err := beszelTests.CreateRecord(hub, "zfs_pools", map[string]any{
+		"system": system.Id,
+		"name":   "tank",
+		"health": "ONLINE",
+	})
+	assert.NoError(t, err)
+
+	// Re-fetch so PocketBase tracks original values
+	pool, err = hub.FindRecordById("zfs_pools", pool.Id)
+	assert.NoError(t, err)
+
+	pool.Set("health", "DEGRADED")
+	err = hub.Save(pool)
+	assert.NoError(t, err)
+
+	time.Sleep(50 * time.Millisecond)
+
+	assert.EqualValues(t, 1, hub.TestMailer.TotalSend(), "should have 1 email sent after pool became DEGRADED")
+	lastMessage := hub.TestMailer.LastMessage()
+	assert.Contains(t, lastMessage.Subject, "Storage pool DEGRADED on test-system")
+	assert.Contains(t, lastMessage.Subject, "tank")
+	assert.Contains(t, lastMessage.Text, "ONLINE to DEGRADED")
+}
+
+func TestZfsPoolAlertDegradedToFaulted(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	system, err := beszelTests.CreateRecord(hub, "systems", map[string]any{
+		"name":  "test-system",
+		"users": []string{user.Id},
+		"host":  "127.0.0.1",
+	})
+	assert.NoError(t, err)
+
+	pool, err := beszelTests.CreateRecord(hub, "zfs_pools", map[string]any{
+		"system": system.Id,
+		"name":   "rpool",
+		"health": "DEGRADED",
+	})
+	assert.NoError(t, err)
+
+	pool, err = hub.FindRecordById("zfs_pools", pool.Id)
+	assert.NoError(t, err)
+
+	pool.Set("health", "FAULTED")
+	err = hub.Save(pool)
+	assert.NoError(t, err)
+
+	time.Sleep(50 * time.Millisecond)
+
+	assert.EqualValues(t, 2, hub.TestMailer.TotalSend(), "should alert on initial DEGRADED state and later FAULTED transition")
+	lastMessage := hub.TestMailer.LastMessage()
+	assert.Contains(t, lastMessage.Subject, "Storage pool FAULTED on test-system")
+}
+
+func TestZfsPoolAlertNoAlertOnRecovery(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	system, err := beszelTests.CreateRecord(hub, "systems", map[string]any{
+		"name":  "test-system",
+		"users": []string{user.Id},
+		"host":  "127.0.0.1",
+	})
+	assert.NoError(t, err)
+
+	pool, err := beszelTests.CreateRecord(hub, "zfs_pools", map[string]any{
+		"system": system.Id,
+		"name":   "tank",
+		"health": "DEGRADED",
+	})
+	assert.NoError(t, err)
+
+	// Trigger a worsening alert first
+	pool, err = hub.FindRecordById("zfs_pools", pool.Id)
+	assert.NoError(t, err)
+	pool.Set("health", "FAULTED")
+	err = hub.Save(pool)
+	assert.NoError(t, err)
+	time.Sleep(50 * time.Millisecond)
+	assert.EqualValues(t, 2, hub.TestMailer.TotalSend(), "expected alerts for initial DEGRADED state and DEGRADED -> FAULTED")
+
+	// Recovery back to ONLINE must not send a new alert
+	pool, err = hub.FindRecordById("zfs_pools", pool.Id)
+	assert.NoError(t, err)
+	pool.Set("health", "ONLINE")
+	err = hub.Save(pool)
+	assert.NoError(t, err)
+	time.Sleep(50 * time.Millisecond)
+	assert.EqualValues(t, 2, hub.TestMailer.TotalSend(), "recovery should not send a new alert")
+
+	// And the open history entry should have been resolved
+	history, err := hub.FindRecordsByFilter("alerts_history", "alert_id={:alert_id}", "", 0, 0, map[string]any{"alert_id": pool.Id})
+	assert.NoError(t, err)
+	requireHistoryResolved(t, history)
+}
+
+func TestZfsPoolAlertUnknownHealthDoesNotResolve(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	system, err := beszelTests.CreateRecord(hub, "systems", map[string]any{
+		"name":  "test-system",
+		"users": []string{user.Id},
+		"host":  "127.0.0.1",
+	})
+	require.NoError(t, err)
+
+	pool, err := beszelTests.CreateRecord(hub, "zfs_pools", map[string]any{
+		"system": system.Id,
+		"name":   "tank",
+		"health": "DEGRADED",
+	})
+	require.NoError(t, err)
+	time.Sleep(50 * time.Millisecond)
+
+	pool, err = hub.FindRecordById("zfs_pools", pool.Id)
+	require.NoError(t, err)
+	pool.Set("health", "")
+	require.NoError(t, hub.Save(pool))
+	time.Sleep(50 * time.Millisecond)
+
+	history, err := hub.FindRecordsByFilter("alerts_history", "alert_id={:alert_id} && resolved=null", "", 0, 0, map[string]any{"alert_id": pool.Id})
+	require.NoError(t, err)
+	require.Len(t, history, 1, "unknown health must not resolve an active alert")
+}
+
+func TestZfsPoolAlertUnknownToFaulted(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	system, err := beszelTests.CreateRecord(hub, "systems", map[string]any{
+		"name":  "test-system",
+		"users": []string{user.Id},
+		"host":  "127.0.0.1",
+	})
+	assert.NoError(t, err)
+
+	pool, err := beszelTests.CreateRecord(hub, "zfs_pools", map[string]any{
+		"system": system.Id,
+		"name":   "tank",
+		"health": "",
+	})
+	assert.NoError(t, err)
+
+	pool, err = hub.FindRecordById("zfs_pools", pool.Id)
+	assert.NoError(t, err)
+
+	pool.Set("health", "FAULTED")
+	err = hub.Save(pool)
+	assert.NoError(t, err)
+
+	time.Sleep(50 * time.Millisecond)
+
+	assert.EqualValues(t, 1, hub.TestMailer.TotalSend(), "should alert when a previously unknown pool becomes FAULTED")
+}
+
+func TestZfsPoolAlertOnInitialUnhealthyState(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	system, err := beszelTests.CreateRecord(hub, "systems", map[string]any{
+		"name":  "test-system",
+		"users": []string{user.Id},
+		"host":  "127.0.0.1",
+	})
+	require.NoError(t, err)
+
+	pool, err := beszelTests.CreateRecord(hub, "zfs_pools", map[string]any{
+		"system": system.Id,
+		"name":   "tank",
+		"health": "DEGRADED",
+	})
+	require.NoError(t, err)
+	time.Sleep(50 * time.Millisecond)
+
+	require.EqualValues(t, 1, hub.TestMailer.TotalSend())
+	assert.Contains(t, hub.TestMailer.LastMessage().Text, "first observed as DEGRADED")
+
+	pool, err = hub.FindRecordById("zfs_pools", pool.Id)
+	require.NoError(t, err)
+	require.NoError(t, hub.Save(pool))
+	time.Sleep(50 * time.Millisecond)
+	assert.EqualValues(t, 1, hub.TestMailer.TotalSend(), "unchanged unhealthy health must not duplicate alerts")
+}
+
+func TestZfsPoolAlertWritesHistory(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	system, err := beszelTests.CreateRecord(hub, "systems", map[string]any{
+		"name":  "test-system",
+		"users": []string{user.Id},
+		"host":  "127.0.0.1",
+	})
+	assert.NoError(t, err)
+
+	pool, err := beszelTests.CreateRecord(hub, "zfs_pools", map[string]any{
+		"system": system.Id,
+		"name":   "tank",
+		"health": "ONLINE",
+	})
+	assert.NoError(t, err)
+
+	pool, err = hub.FindRecordById("zfs_pools", pool.Id)
+	assert.NoError(t, err)
+	pool.Set("health", "FAULTED")
+	err = hub.Save(pool)
+	assert.NoError(t, err)
+
+	time.Sleep(50 * time.Millisecond)
+
+	history, err := hub.FindRecordsByFilter("alerts_history", "alert_id={:alert_id}", "", 0, 0, map[string]any{"alert_id": pool.Id})
+	assert.NoError(t, err)
+	require.Len(t, history, 1, "expected one history entry per user")
+	assert.Equal(t, "Storage Pool: tank", history[0].GetString("name"))
+	assert.Equal(t, system.Id, history[0].GetString("system"))
+}
+
+func TestZfsPoolAlertResolvedOnRecordDelete(t *testing.T) {
+	hub, user := beszelTests.GetHubWithUser(t)
+	defer hub.Cleanup()
+
+	system, err := beszelTests.CreateRecord(hub, "systems", map[string]any{
+		"name":  "test-system",
+		"users": []string{user.Id},
+		"host":  "127.0.0.1",
+	})
+	assert.NoError(t, err)
+
+	pool, err := beszelTests.CreateRecord(hub, "zfs_pools", map[string]any{
+		"system": system.Id,
+		"name":   "tank",
+		"health": "ONLINE",
+	})
+	assert.NoError(t, err)
+
+	// Trigger an alert so an open history entry exists.
+	pool, err = hub.FindRecordById("zfs_pools", pool.Id)
+	assert.NoError(t, err)
+	pool.Set("health", "FAULTED")
+	err = hub.Save(pool)
+	assert.NoError(t, err)
+	time.Sleep(50 * time.Millisecond)
+
+	history, err := hub.FindRecordsByFilter("alerts_history", "alert_id={:alert_id} && resolved=null", "", 0, 0, map[string]any{"alert_id": pool.Id})
+	assert.NoError(t, err)
+	require.Len(t, history, 1, "expected one open history entry")
+
+	// Deleting the pool record must resolve the open entry.
+	err = hub.Delete(pool)
+	assert.NoError(t, err)
+	time.Sleep(50 * time.Millisecond)
+
+	history, err = hub.FindRecordsByFilter("alerts_history", "alert_id={:alert_id}", "", 0, 0, map[string]any{"alert_id": pool.Id})
+	assert.NoError(t, err)
+	require.Len(t, history, 1)
+	requireHistoryResolved(t, history)
+}
+
+func requireHistoryResolved(t *testing.T, history []*core.Record) {
+	t.Helper()
+	for _, record := range history {
+		assert.False(t, record.GetDateTime("resolved").Time().IsZero(), "expected history entry to be resolved")
+	}
+}

internal/alerts/notification_client.go

@@ -0,0 +1,150 @@
+package alerts
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"net/netip"
+	"sync/atomic"
+	"syscall"
+	"time"
+
+	"github.com/nicholas-fedor/shoutrrr/pkg/router"
+	"github.com/nicholas-fedor/shoutrrr/pkg/types"
+)
+
+var (
+	errInternalDestination   = errors.New("Only admins can send to internal destinations")
+	errUnrestrictedService   = errors.New("Only admins can use this notification service") // Restrict services w/o custom connection support
+	publicNotificationDialer = &net.Dialer{
+		Timeout: 10 * time.Second,
+		// Control checks each resolved address immediately before connecting.
+		Control: func(_, address string, _ syscall.RawConn) error { return checkNotificationAddress(address) },
+	}
+	publicNotificationClient = newPublicNotificationClient()
+)
+
+func newPublicNotificationClient() *http.Client {
+	return &http.Client{
+		Timeout: 15 * time.Second,
+		Transport: &http.Transport{
+			// Do not use proxies: they can resolve the target themselves and
+			// bypass the destination check on our socket.
+			DialContext:         publicNotificationDialer.DialContext,
+			TLSHandshakeTimeout: 10 * time.Second,
+			IdleConnTimeout:     90 * time.Second,
+		},
+	}
+}
+
+func checkNotificationAddress(address string) error {
+	addr, err := netip.ParseAddrPort(address)
+	if err != nil || addr.Addr().Zone() != "" {
+		return errInternalDestination
+	}
+	ip := net.IP(addr.Addr().AsSlice())
+	if !ip.IsGlobalUnicast() || isInternalIP(ip) {
+		return errInternalDestination
+	}
+	return nil
+}
+
+func sendPublicNotification(rawURL, message string) error {
+	client := &notificationClient{Client: publicNotificationClient}
+	service, err := newPublicNotificationService(rawURL, types.SenderOptions{HTTPClient: client, DialContext: client.dialContext})
+	if err == nil {
+		if closer, ok := service.(io.Closer); ok {
+			defer closer.Close()
+		}
+		err = service.Send(message, &types.Params{})
+	}
+	// Some services format errors without preserving their error chain.
+	if client.blocked.Load() {
+		return errInternalDestination
+	}
+	return err
+}
+
+type notificationClient struct {
+	*http.Client
+	blocked atomic.Bool
+}
+
+func (c *notificationClient) Do(req *http.Request) (*http.Response, error) {
+	response, err := c.Client.Do(req)
+	if errors.Is(err, errInternalDestination) {
+		c.blocked.Store(true)
+	}
+	return response, err
+}
+
+func (c *notificationClient) dialContext(ctx context.Context, network, address string) (net.Conn, error) {
+	conn, err := publicNotificationDialer.DialContext(ctx, network, address)
+	if errors.Is(err, errInternalDestination) {
+		c.blocked.Store(true)
+	}
+	return conn, err
+}
+
+func newPublicNotificationService(rawURL string, opts types.SenderOptions) (types.Service, error) {
+	r := &router.ServiceRouter{}
+	scheme, serviceURL, err := r.ExtractServiceName(rawURL)
+	if err != nil {
+		return nil, err
+	}
+	service, err := r.NewService(scheme)
+	if err != nil {
+		return nil, err
+	}
+	httpSetter, httpOK := service.(types.HTTPClientSetter)
+	dialSetter, dialOK := service.(types.DialContextSetter)
+	if (!httpOK || opts.HTTPClient == nil) && (!dialOK || opts.DialContext == nil) {
+		return nil, errUnrestrictedService
+	}
+	if serviceURL.Scheme != scheme {
+		custom, ok := service.(types.CustomURLService)
+		if !ok {
+			return nil, fmt.Errorf("%w: %s", router.ErrCustomURLsNotSupported, scheme)
+		}
+		serviceURL, err = custom.GetServiceURLFromCustom(serviceURL)
+		if err != nil {
+			return nil, err
+		}
+	}
+	// Shoutrrr v0.20.0 CreateSenderWithOptions injects only AFTER Initialize.
+	// Matrix can log in during Initialize, so inject before it as well.
+	if httpOK {
+		httpSetter.SetHTTPClient(opts.HTTPClient)
+	}
+	if dialOK {
+		dialSetter.SetDialContext(opts.DialContext)
+	}
+	if err := service.Initialize(serviceURL, nil); err != nil {
+		return nil, err
+	}
+	// Some initializers replace their HTTP client with a default client.
+	if httpOK {
+		httpSetter.SetHTTPClient(opts.HTTPClient)
+	}
+	if dialOK {
+		dialSetter.SetDialContext(opts.DialContext)
+	}
+	return service, nil
+}
+
+var cgnatNetwork = &net.IPNet{
+	IP:   net.IPv4(100, 64, 0, 0),
+	Mask: net.CIDRMask(10, 32),
+}
+
+func isInternalIP(ip net.IP) bool {
+	return ip.IsPrivate() ||
+		ip.IsLoopback() ||
+		ip.IsUnspecified() ||
+		ip.IsLinkLocalUnicast() ||
+		ip.IsMulticast() ||
+		cgnatNetwork.Contains(ip)
+}

internal/alerts/notification_client_test.go

@@ -0,0 +1,217 @@
+package alerts
+
+import (
+	"context"
+	"encoding/binary"
+	"errors"
+	"io"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"sync/atomic"
+	"testing"
+
+	"github.com/nicholas-fedor/shoutrrr/pkg/types"
+	"golang.org/x/net/dns/dnsmessage"
+)
+
+func TestCheckNotificationAddress(t *testing.T) {
+	for _, host := range []string{"127.0.0.1", "10.0.0.1", "172.16.0.1", "192.168.0.1", "169.254.169.254", "100.64.0.0", "100.127.255.255", "0.0.0.0", "224.0.0.1", "255.255.255.255", "::1", "::", "fc00::1", "fe80::1", "ff02::1", "::ffff:127.0.0.1", "::ffff:169.254.169.254", "fe80::1%lo", "localhost", "consul"} {
+		t.Run(host, func(t *testing.T) {
+			if err := checkNotificationAddress(net.JoinHostPort(host, "80")); !errors.Is(err, errInternalDestination) {
+				t.Fatalf("expected blocked address, got %v", err)
+			}
+		})
+	}
+	for _, host := range []string{"8.8.8.8", "100.63.255.255", "100.128.0.0", "2001:4860:4860::8888"} {
+		if err := checkNotificationAddress(net.JoinHostPort(host, "443")); err != nil {
+			t.Errorf("public address %s: %v", host, err)
+		}
+	}
+}
+
+func TestPublicNotificationBlocksInternalRequests(t *testing.T) {
+	var hits atomic.Int32
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		hits.Add(1)
+	}))
+	defer server.Close()
+	host := strings.TrimPrefix(server.URL, "http://")
+	for _, rawURL := range []string{
+		"generic+http://" + host,
+		"generic+https://" + host,
+		"generic+http://localhost:" + strings.Split(host, ":")[1],
+		"matrix://user:password@" + host + "/room?disabletls=yes",
+		"mattermost://" + host + "/token?disabletls=yes",
+	} {
+		t.Run(rawURL, func(t *testing.T) {
+			if err := sendPublicNotification(rawURL, "test"); !errors.Is(err, errInternalDestination) {
+				t.Fatalf("expected internal destination error, got %v", err)
+			}
+		})
+	}
+	if hits.Load() != 0 {
+		t.Fatal("internal server received a request")
+	}
+
+}
+
+type notificationRoundTripper func(*http.Request) (*http.Response, error)
+
+func (f notificationRoundTripper) RoundTrip(r *http.Request) (*http.Response, error) { return f(r) }
+
+func TestPublicNotificationRedirect(t *testing.T) {
+	client := newPublicNotificationClient()
+	defer client.CloseIdleConnections()
+	transport := client.Transport
+	client.Transport = notificationRoundTripper(func(r *http.Request) (*http.Response, error) {
+		if r.URL.Host == "public.example" {
+			return &http.Response{StatusCode: 307, Header: http.Header{"Location": {"http://127.0.0.1/"}}, Body: io.NopCloser(strings.NewReader("")), Request: r}, nil
+		}
+		return transport.RoundTrip(r)
+	})
+	_, err := client.Get("http://public.example/")
+	if !errors.Is(err, errInternalDestination) {
+		t.Fatalf("expected redirect to be blocked, got %v", err)
+	}
+}
+
+func TestPublicNotificationServiceClient(t *testing.T) {
+	for _, rawURL := range []string{"generic+http://public.example/path", "discord://token@123456789", "slack://hook:AAAAAAAAA-BBBBBBBBB-123456789123456789123456@webhook"} {
+		t.Run(rawURL, func(t *testing.T) {
+			var hits int
+			client := &http.Client{Transport: notificationRoundTripper(func(r *http.Request) (*http.Response, error) {
+				hits++
+				body := `{"ok":true}`
+				if strings.HasPrefix(rawURL, "slack:") {
+					body = "ok"
+				}
+				return &http.Response{StatusCode: 200, Header: make(http.Header), Body: io.NopCloser(strings.NewReader(body)), Request: r}, nil
+			})}
+			service, err := newPublicNotificationService(rawURL, types.SenderOptions{HTTPClient: client})
+			if err != nil {
+				t.Fatal(err)
+			}
+			if err := service.Send("test", &types.Params{}); err != nil {
+				t.Fatal(err)
+			}
+			if hits == 0 {
+				t.Fatal("injected client was not used")
+			}
+		})
+	}
+}
+
+func TestPublicNotificationDNS(t *testing.T) {
+	// Supply deterministic DNS responses over an in-memory TCP connection.
+	// The first lookup sees a public IP; subsequent lookups see loopback.
+	var rebound atomic.Bool
+	resolver := &net.Resolver{PreferGo: true, Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+		client, server := net.Pipe()
+		go func() {
+			defer server.Close()
+			var size [2]byte
+			if _, err := io.ReadFull(server, size[:]); err != nil {
+				return
+			}
+			buf := make([]byte, binary.BigEndian.Uint16(size[:]))
+			if _, err := io.ReadFull(server, buf); err != nil {
+				return
+			}
+			var msg dnsmessage.Message
+			if err := msg.Unpack(buf); err != nil {
+				return
+			}
+			msg.Header.Response = true
+			msg.Header.RecursionAvailable = true
+			q := msg.Questions[0]
+			if q.Type == dnsmessage.TypeA {
+				ip := [4]byte{8, 8, 8, 8}
+				if rebound.Load() {
+					ip = [4]byte{127, 0, 0, 1}
+				}
+				msg.Answers = []dnsmessage.Resource{{Header: dnsmessage.ResourceHeader{Name: q.Name, Type: q.Type, Class: dnsmessage.ClassINET}, Body: &dnsmessage.AResource{A: ip}}}
+			}
+			buf, err := msg.Pack()
+			if err != nil {
+				return
+			}
+			binary.BigEndian.PutUint16(size[:], uint16(len(buf)))
+			server.Write(append(size[:], buf...))
+		}()
+		return client, nil
+	}}
+	// These tests do not run in parallel; restore the process resolver afterward.
+	previous := net.DefaultResolver
+	net.DefaultResolver = resolver
+	t.Cleanup(func() { net.DefaultResolver = previous })
+	ips, err := resolver.LookupIP(context.Background(), "ip4", "rebind.example")
+	if err != nil || len(ips) != 1 || !ips[0].Equal(net.IPv4(8, 8, 8, 8)) {
+		t.Fatalf("initial DNS lookup: %v, %v", ips, err)
+	}
+	rebound.Store(true)
+	client := newPublicNotificationClient()
+	defer client.CloseIdleConnections()
+	for _, host := range []string{"rebind.example", "consul"} {
+		guarded := &notificationClient{Client: client}
+		conn, dialErr := guarded.dialContext(context.Background(), "tcp", net.JoinHostPort(host, "25"))
+		if conn != nil {
+			conn.Close()
+		}
+		if !errors.Is(dialErr, errInternalDestination) || !guarded.blocked.Load() {
+			t.Errorf("expected TCP dial-time rejection for %s, got %v", host, dialErr)
+		}
+		_, err := client.Get("http://" + host + "/")
+		if !errors.Is(err, errInternalDestination) {
+			t.Errorf("expected dial-time rejection for %s, got %v", host, err)
+		}
+	}
+}
+
+func TestPublicNotificationTCP(t *testing.T) {
+	for _, rawURL := range []string{
+		"smtp://user:pass@HOST:25/?fromAddress=sender@example.com&toAddresses=recipient@example.com",
+		"smtp://user:pass@HOST:465/?fromAddress=sender@example.com&toAddresses=recipient@example.com",
+		"mqtt://HOST:1883/topic",
+		"mqtts://HOST:8883/topic",
+	} {
+		t.Run(rawURL, func(t *testing.T) {
+			t.Parallel()
+			t.Run("internal destination", func(t *testing.T) {
+				err := sendPublicNotification(strings.ReplaceAll(rawURL, "HOST", "127.0.0.1"), "test")
+				if !errors.Is(err, errInternalDestination) {
+					t.Fatalf("expected blocked destination, got %v", err)
+				}
+			})
+			t.Run("public destination uses injected dialer", func(t *testing.T) {
+				var calls atomic.Int32
+				stopped := errors.New("test dial stopped")
+				service, err := newPublicNotificationService(strings.ReplaceAll(rawURL, "HOST", "8.8.8.8"), types.SenderOptions{
+					DialContext: func(ctx context.Context, network, address string) (net.Conn, error) {
+						calls.Add(1)
+						if network != "tcp" || !strings.HasPrefix(address, "8.8.8.8:") {
+							t.Errorf("unexpected dial: %s %s", network, address)
+						}
+						if err := checkNotificationAddress(address); err != nil {
+							t.Error(err)
+						}
+						return nil, stopped
+					},
+				})
+				if err != nil {
+					t.Fatal(err)
+				}
+				if closer, ok := service.(io.Closer); ok {
+					defer closer.Close()
+				}
+				if err := service.Send("test", &types.Params{}); err == nil {
+					t.Fatal("expected dial failure")
+				}
+				if calls.Load() == 0 {
+					t.Fatal("custom dialer was not used")
+				}
+			})
+		})
+	}
+}

internal/common/common-ws.go

@@ -22,6 +22,8 @@ const (
 	GetSmartData
 	// Request detailed systemd service info from agent
 	GetSystemdInfo
+	// Request ZFS detail data from agent
+	GetZfsData
 	// Add new actions here...
 )
 
@@ -64,6 +66,10 @@ type DataRequestOptions struct {
 	IncludeDetails bool   `cbor:"1,keyasint"`
 }
 
+type ZfsDataRequest struct {
+	Force bool `cbor:"0,keyasint,omitempty"`
+}
+
 type ContainerLogsRequest struct {
 	ContainerID string `cbor:"0,keyasint"`
 }

internal/dockerfile_agent

@@ -8,6 +8,8 @@ RUN go mod download
 # Copy source files
 COPY . ./
 
+RUN apk add --no-cache ca-certificates && update-ca-certificates
+
 # Build
 ARG TARGETOS TARGETARCH
 RUN CGO_ENABLED=0 GOGC=75 GOOS=$TARGETOS GOARCH=$TARGETARCH go build -ldflags "-w -s" -o /agent ./internal/cmd/agent
@@ -19,6 +21,7 @@ RUN rm -rf /tmp/*
 # --------------------------
 FROM scratch
 COPY --from=builder /agent /agent
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 
 # this is so we don't need to create the /tmp directory in the scratch container
 COPY --from=builder /tmp /tmp
@@ -29,4 +32,4 @@ COPY --from=builder /app/agent/test-data/amdgpu.ids /usr/share/libdrm/amdgpu.ids
 # Ensure data persistence across container recreations
 VOLUME ["/var/lib/beszel-agent"]
 
-ENTRYPOINT ["/agent"]
+ENTRYPOINT ["/agent"]

internal/dockerfile_agent_alpine

@@ -23,7 +23,7 @@ COPY --from=builder /agent /agent
 # AMD GPU name lookup (used by agent on Linux when /usr/share/libdrm/amdgpu.ids is read)
 COPY --from=builder /app/agent/test-data/amdgpu.ids /usr/share/libdrm/amdgpu.ids
 
-RUN apk add --no-cache smartmontools
+RUN apk add --no-cache smartmontools zfs
 
 # Ensure data persistence across container recreations
 VOLUME ["/var/lib/beszel-agent"]

internal/dockerfile_agent_intel

@@ -20,9 +20,9 @@ FROM alpine:3.23
 
 COPY --from=builder /agent /agent
 
-RUN apk add --no-cache -X https://dl-cdn.alpinelinux.org/alpine/edge/testing igt-gpu-tools nvtop smartmontools
+RUN apk add --no-cache -X https://dl-cdn.alpinelinux.org/alpine/edge/testing igt-gpu-tools nvtop smartmontools zfs
 
 # Ensure data persistence across container recreations
 VOLUME ["/var/lib/beszel-agent"]
 
-ENTRYPOINT ["/agent"]
+ENTRYPOINT ["/agent"]

internal/dockerfile_agent_nvidia

@@ -43,6 +43,11 @@ COPY --from=builder /app/agent/test-data/amdgpu.ids /usr/share/libdrm/amdgpu.ids
 # Copy smartmontools binaries and config files
 COPY --from=smartmontools-builder /usr/sbin/smartctl /usr/sbin/smartctl
 
+# Install ZFS userspace utilities (zpool, zfs) for pool/dataset monitoring
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  zfsutils-linux \
+  && apt-get clean && rm -rf /var/lib/apt/lists/*
+
 # Ensure data persistence across container recreations
 VOLUME ["/var/lib/beszel-agent"]
 

internal/dockerfile_agent_nvidia_slim

@@ -65,6 +65,32 @@ RUN set -eux; \
     cp -v "$interp" "/out/rootfs$interp"; \
   fi
 
+# --------------------------
+# ZFS utilities builder stage
+# --------------------------
+FROM --platform=$TARGETPLATFORM debian:bookworm-slim AS zfsutils-builder
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+  zfsutils-linux \
+  && rm -rf /var/lib/apt/lists/*
+
+# Copy the zpool/zfs binaries and their required runtime libraries
+RUN set -eux; \
+  mkdir -p /out/rootfs/lib /out/rootfs/lib64 /out/rootfs/usr/lib; \
+  for bin in /usr/sbin/zpool /usr/sbin/zfs; do \
+    mkdir -p "/out/rootfs$(dirname "$bin")"; \
+    cp -v "$bin" "/out/rootfs$bin"; \
+    ldd "$bin" \
+      | awk '{print $3}' \
+      | grep '^/' \
+      | xargs -r -I '{}' sh -c 'mkdir -p "/out/rootfs$(dirname "{}")"; cp -v "{}" "/out/rootfs{}"'; \
+    interp="$(ldd "$bin" | awk "/ld-linux/ {print \$1}")"; \
+    if [ -n "$interp" ] && [ -e "$interp" ]; then \
+      mkdir -p "/out/rootfs$(dirname "$interp")"; \
+      cp -v "$interp" "/out/rootfs$interp"; \
+    fi; \
+  done
+
 # --------------------------
 # Final image: lightweight multi-arch NVIDIA agent (slim)
 # --------------------------
@@ -78,6 +104,9 @@ COPY --from=builder /app/agent/test-data/amdgpu.ids /usr/share/libdrm/amdgpu.ids
 COPY --from=smartmontools-builder /usr/sbin/smartctl /usr/sbin/smartctl
 COPY --from=smartmontools-builder /out/rootfs/ /
 
+# Copy ZFS utilities (zpool, zfs) binaries and required runtime libraries
+COPY --from=zfsutils-builder /out/rootfs/ /
+
 # nvidia-smi is intentionally not bundled.
 # Mount the host binary instead, for example:
 # - /usr/bin/nvidia-smi:/usr/bin/nvidia-smi:ro

internal/entities/container/container.go

@@ -186,11 +186,12 @@ type Stats struct {
 	NetworkRecv float64   `json:"nr,omitzero" cbor:"4,keyasint,omitzero"` // deprecated 0.18.3 (MB) - keep field for old agents/records
 	Bandwidth   [2]uint64 `json:"b,omitzero" cbor:"9,keyasint,omitzero"`  // [sent bytes, recv bytes]
 
-	Health DockerHealth `json:"-" cbor:"5,keyasint"`
+	Health          DockerHealth `json:"-" cbor:"5,keyasint"`
-	Status string       `json:"-" cbor:"6,keyasint"`
+	Status          string       `json:"-" cbor:"6,keyasint"`
-	Id     string       `json:"-" cbor:"7,keyasint"`
+	Id              string       `json:"-" cbor:"7,keyasint"`
-	Image  string       `json:"-" cbor:"8,keyasint"`
+	Image           string       `json:"-" cbor:"8,keyasint"`
-	Ports  string       `json:"-" cbor:"10,keyasint"`
+	Ports           string       `json:"-" cbor:"10,keyasint"`
+	UpdateAvailable bool         `json:"u,omitzero" cbor:"11,keyasint,omitzero"`
 	// PrevCpu     [2]uint64    `json:"-"`
 	CpuSystem    uint64       `json:"-"`
 	CpuContainer uint64       `json:"-"`

internal/entities/system/system.go

@@ -33,8 +33,6 @@ type Stats struct {
 	MaxNetworkSent float64             `json:"nsm,omitempty" cbor:"-"`
 	MaxNetworkRecv float64             `json:"nrm,omitempty" cbor:"-"`
 	Temperatures   map[string]float64  `json:"t,omitempty" cbor:"20,keyasint,omitempty"`
-	Fans           map[string]uint16   `json:"f,omitempty" cbor:"36,keyasint,omitempty"`
-	Batteries      map[string]uint8    `json:"bats,omitempty" cbor:"37,keyasint,omitempty"`
 	ExtraFs        map[string]*FsStats `json:"efs,omitempty" cbor:"21,keyasint,omitempty"`
 	GPUData        map[string]GPUData  `json:"g,omitempty" cbor:"22,keyasint,omitempty"`
 	// LoadAvg1       float64             `json:"l1,omitempty" cbor:"23,keyasint,omitempty"`
@@ -44,7 +42,7 @@ type Stats struct {
 	MaxBandwidth [2]uint64 `json:"bm,omitzero" cbor:"-"`                   // [sent bytes, recv bytes]
 	// TODO: remove other load fields in future release in favor of load avg array
 	LoadAvg           [3]float64           `json:"la,omitempty" cbor:"28,keyasint"`
-	Battery           [2]uint8             `json:"bat,omitzero" cbor:"29,keyasint,omitzero"`    // [percent, charge state]
+	Battery           Battery              `json:"bat,omitzero" cbor:"29,keyasint,omitzero"`    // [percent, charge state]
 	NetworkInterfaces map[string][4]uint64 `json:"ni,omitempty" cbor:"31,keyasint,omitempty"`   // [upload bytes, download bytes, total upload, total download]
 	DiskIO            [2]uint64            `json:"dio,omitzero" cbor:"32,keyasint,omitzero"`    // [read bytes, write bytes]
 	MaxDiskIO         [2]uint64            `json:"diom,omitzero" cbor:"-"`                      // [max read bytes, max write bytes]
@@ -52,6 +50,24 @@ type Stats struct {
 	CpuCoresUsage     Uint8Slice           `json:"cpus,omitempty" cbor:"34,keyasint,omitempty"` // per-core busy usage [CPU0..]
 	DiskIoStats       [6]float64           `json:"dios,omitzero" cbor:"35,keyasint,omitzero"`   // [read time %, write time %, io utilization %, r_await ms, w_await ms, weighted io %]
 	MaxDiskIoStats    [6]float64           `json:"diosm,omitzero" cbor:"-"`                     // max values for DiskIoStats
+	Fans              map[string]uint16    `json:"f,omitempty" cbor:"36,keyasint,omitempty"`
+	Batteries         map[string]uint8     `json:"bats,omitempty" cbor:"37,keyasint,omitempty"`
+	ZfsPools          map[string]*ZfsPool  `json:"z,omitempty" cbor:"39,keyasint,omitempty"`  // ZFS pool metrics, keyed by pool name
+	DiskIOTotal       [2]uint64            `json:"diot,omitzero" cbor:"38,keyasint,omitzero"` // [total read bytes, total write bytes] cumulative device counters
+
+}
+
+// ZfsPool holds per-pool ZFS metrics for a single collection interval.
+type ZfsPool struct {
+	DisplayName string  `json:"n,omitempty" cbor:"8,keyasint,omitempty"`
+	HideUsage   bool    `json:"hu,omitempty" cbor:"6,keyasint,omitempty"` // equivalent filesystem usage chart exists
+	HideIO      bool    `json:"hi,omitempty" cbor:"7,keyasint,omitempty"` // equivalent filesystem I/O chart exists
+	Raw         bool    `json:"raw,omitempty" cbor:"5,keyasint,omitempty"`
+	Total       float64 `json:"d" cbor:"0,keyasint"`                     // total capacity in GiB
+	Used        float64 `json:"du" cbor:"1,keyasint"`                    // allocated in GiB
+	ReadBytes   uint64  `json:"rb,omitzero" cbor:"2,keyasint,omitzero"`  // read throughput in bytes/s
+	WriteBytes  uint64  `json:"wb,omitzero" cbor:"3,keyasint,omitzero"`  // write throughput in bytes/s
+	Health      string  `json:"h,omitempty" cbor:"4,keyasint,omitempty"` // ONLINE, DEGRADED, FAULTED, ...
 }
 
 // Uint8Slice wraps []uint8 to customize JSON encoding while keeping CBOR efficient.
@@ -71,6 +87,15 @@ func (s Uint8Slice) MarshalJSON() ([]byte, error) {
 	return json.Marshal(arr)
 }
 
+// Battery stores the representative battery's percent and charge state.
+// Its custom JSON encoding keeps the public and persisted representation as a
+// numeric tuple under both encoding/json v1 and v2.
+type Battery [2]uint8
+
+func (b Battery) MarshalJSON() ([]byte, error) {
+	return json.Marshal([2]uint16{uint16(b[0]), uint16(b[1])})
+}
+
 type GPUData struct {
 	Name        string             `json:"n" cbor:"0,keyasint"`
 	Temperature float64            `json:"-"`
@@ -90,8 +115,8 @@ type FsStats struct {
 	Name           string    `json:"-"`
 	DiskTotal      float64   `json:"d" cbor:"0,keyasint"`
 	DiskUsed       float64   `json:"du" cbor:"1,keyasint"`
-	TotalRead      uint64    `json:"-"`
+	TotalRead      uint64    `json:"tr,omitzero" cbor:"9,keyasint,omitzero"`  // cumulative device read bytes
-	TotalWrite     uint64    `json:"-"`
+	TotalWrite     uint64    `json:"tw,omitzero" cbor:"10,keyasint,omitzero"` // cumulative device write bytes
 	DiskReadPs     float64   `json:"r" cbor:"2,keyasint"`
 	DiskWritePs    float64   `json:"w" cbor:"3,keyasint"`
 	MaxDiskReadPS  float64   `json:"rm,omitempty" cbor:"-"`
@@ -155,8 +180,9 @@ type Info struct {
 	LoadAvg        [3]float64         `json:"la,omitempty" cbor:"19,keyasint"`
 	ConnectionType ConnectionType     `json:"ct,omitempty" cbor:"20,keyasint,omitempty,omitzero"`
 	ExtraFsPct     map[string]float64 `json:"efs,omitempty" cbor:"21,keyasint,omitempty"`
-	Services       []uint16           `json:"sv,omitempty" cbor:"22,keyasint,omitempty"` // [totalServices, numFailedServices]
+	Services       []uint16           `json:"sv,omitempty" cbor:"22,keyasint,omitempty"`  // [totalServices, numFailedServices]
-	Battery        [2]uint8           `json:"bat,omitzero" cbor:"23,keyasint,omitzero"`  // [percent, charge state]
+	Battery        Battery            `json:"bat,omitzero" cbor:"23,keyasint,omitzero"`   // [percent, charge state]
+	RootDiskName   string             `json:"rdn,omitempty" cbor:"24,keyasint,omitempty"` // custom name for root disk (set via FILESYSTEM=device__name)
 }
 
 // Data that does not change during process lifetime and is not needed in All Systems table
@@ -172,6 +198,7 @@ type Details struct {
 	Podman        bool          `cbor:"8,keyasint,omitempty"`
 	MemoryTotal   uint64        `cbor:"9,keyasint"`
 	SmartInterval time.Duration `cbor:"10,keyasint,omitempty"`
+	ZfsInterval   time.Duration `cbor:"11,keyasint,omitempty"` // interval for ZFS detail refresh
 }
 
 // Final data structure to return to the hub
@@ -181,4 +208,7 @@ type CombinedData struct {
 	Containers      []*container.Stats `json:"container" cbor:"2,keyasint"`
 	SystemdServices []*systemd.Service `json:"systemd,omitempty" cbor:"3,keyasint,omitempty"`
 	Details         *Details           `cbor:"4,keyasint,omitempty"`
+	// SystemdServicesUpdated distinguishes a fresh empty snapshot from a response
+	// that omitted systemd data (for example, a short-cache dashboard request).
+	SystemdServicesUpdated bool `json:"systemdUpdated,omitempty" cbor:"5,keyasint,omitempty"`
 }

internal/entities/system/system_test.go

@@ -2,9 +2,11 @@ package system
 
 import (
 	"encoding/json"
+	jsonv2 "encoding/json/v2"
 	"testing"
 
 	"github.com/fxamacker/cbor/v2"
+	"github.com/henrygd/beszel/internal/entities/container"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -12,12 +14,19 @@ import (
 func TestStatsBatteryTransport(t *testing.T) {
 	stats := Stats{Battery: [2]uint8{0, 1}, Batteries: map[string]uint8{"Primary": 0, "Mouse": 75}}
 
-	jsonData, err := json.Marshal(stats)
+	for name, marshal := range map[string]func(any) ([]byte, error){
-	require.NoError(t, err)
+		"json_v1": json.Marshal,
-	var jsonPayload map[string]any
+		"json_v2": func(value any) ([]byte, error) { return jsonv2.Marshal(value) },
-	require.NoError(t, json.Unmarshal(jsonData, &jsonPayload))
+	} {
-	assert.Equal(t, []any{float64(0), float64(1)}, jsonPayload["bat"])
+		t.Run(name, func(t *testing.T) {
-	assert.Equal(t, map[string]any{"Primary": float64(0), "Mouse": float64(75)}, jsonPayload["bats"])
+			jsonData, err := marshal(stats)
+			require.NoError(t, err)
+			var jsonPayload map[string]any
+			require.NoError(t, json.Unmarshal(jsonData, &jsonPayload))
+			assert.Equal(t, []any{float64(0), float64(1)}, jsonPayload["bat"])
+			assert.Equal(t, map[string]any{"Primary": float64(0), "Mouse": float64(75)}, jsonPayload["bats"])
+		})
+	}
 
 	cborData, err := cbor.Marshal(stats)
 	require.NoError(t, err)
@@ -27,6 +36,26 @@ func TestStatsBatteryTransport(t *testing.T) {
 	assert.Equal(t, stats.Batteries, decoded.Batteries)
 }
 
+func TestStatsDiskIOTotalAndFansTransport(t *testing.T) {
+	stats := Stats{
+		DiskIOTotal: [2]uint64{437348527104, 331522465792},
+		Fans:        map[string]uint16{"cpu": 1200},
+	}
+
+	cborData, err := cbor.Marshal(stats)
+	require.NoError(t, err)
+	var decoded Stats
+	require.NoError(t, cbor.Unmarshal(cborData, &decoded))
+	assert.Equal(t, stats.DiskIOTotal, decoded.DiskIOTotal)
+	assert.Equal(t, stats.Fans, decoded.Fans)
+}
+
+func TestStatsBatteryNumericArrayUnmarshal(t *testing.T) {
+	var stats Stats
+	require.NoError(t, json.Unmarshal([]byte(`{"bat":[50,4]}`), &stats))
+	assert.Equal(t, Battery{50, 4}, stats.Battery)
+}
+
 func TestStatsLegacyBatteryPayload(t *testing.T) {
 	data, err := json.Marshal(Stats{Battery: [2]uint8{50, 4}})
 	require.NoError(t, err)
@@ -35,3 +64,56 @@ func TestStatsLegacyBatteryPayload(t *testing.T) {
 	assert.Contains(t, payload, "bat")
 	assert.NotContains(t, payload, "bats")
 }
+
+func TestCombinedDataSystemdUpdateMarkerTransport(t *testing.T) {
+	data := CombinedData{SystemdServicesUpdated: true}
+
+	jsonData, err := json.Marshal(data)
+	require.NoError(t, err)
+	var decodedJSON CombinedData
+	require.NoError(t, json.Unmarshal(jsonData, &decodedJSON))
+	assert.True(t, decodedJSON.SystemdServicesUpdated)
+	assert.Empty(t, decodedJSON.SystemdServices)
+
+	cborData, err := cbor.Marshal(data)
+	require.NoError(t, err)
+	var decodedCBOR CombinedData
+	require.NoError(t, cbor.Unmarshal(cborData, &decodedCBOR))
+	assert.True(t, decodedCBOR.SystemdServicesUpdated)
+	assert.Empty(t, decodedCBOR.SystemdServices)
+
+	var legacy CombinedData
+	require.NoError(t, json.Unmarshal([]byte(`{"stats":{},"info":{},"container":[]}`), &legacy))
+	assert.False(t, legacy.SystemdServicesUpdated)
+}
+
+func TestCombinedDataContainerValidityTransport(t *testing.T) {
+	validEmpty := CombinedData{Containers: []*container.Stats{}}
+
+	jsonData, err := json.Marshal(validEmpty)
+	require.NoError(t, err)
+	var decodedJSON CombinedData
+	require.NoError(t, json.Unmarshal(jsonData, &decodedJSON))
+	assert.NotNil(t, decodedJSON.Containers)
+	assert.Empty(t, decodedJSON.Containers)
+
+	jsonV2Data, err := jsonv2.Marshal(validEmpty)
+	require.NoError(t, err)
+	var decodedJSONV2 CombinedData
+	require.NoError(t, jsonv2.Unmarshal(jsonV2Data, &decodedJSONV2))
+	assert.NotNil(t, decodedJSONV2.Containers)
+	assert.Empty(t, decodedJSONV2.Containers)
+
+	cborData, err := cbor.Marshal(validEmpty)
+	require.NoError(t, err)
+	var decodedCBOR CombinedData
+	require.NoError(t, cbor.Unmarshal(cborData, &decodedCBOR))
+	assert.NotNil(t, decodedCBOR.Containers)
+	assert.Empty(t, decodedCBOR.Containers)
+
+	invalidData, err := cbor.Marshal(CombinedData{})
+	require.NoError(t, err)
+	var decodedInvalid CombinedData
+	require.NoError(t, cbor.Unmarshal(invalidData, &decodedInvalid))
+	assert.Nil(t, decodedInvalid.Containers)
+}

internal/entities/zfs/zfs.go

@@ -0,0 +1,69 @@
+// Package zfs defines the ZFS detail data exchanged between agent and hub.
+package zfs
+
+import "strings"
+
+// ZfsData is the detail payload returned by the agent for the GetZfsData action.
+type ZfsData struct {
+	Pools    []*PoolDetail `json:"pools,omitempty"`
+	Complete bool          `json:"complete,omitempty"`
+	// Backends whose inventories are complete, even when another backend failed.
+	CompleteBackends []string `json:"completeBackends,omitempty"`
+}
+
+// CanRefreshPool also governs deletion: missing pools may only be removed
+// after a successful inventory of their backend. Complete supports old agents.
+func (data *ZfsData) CanRefreshPool(name string) bool {
+	if data.Complete {
+		return true
+	}
+	backend := "zfs"
+	if strings.HasPrefix(name, "b:") {
+		backend = "btrfs"
+	}
+	for _, complete := range data.CompleteBackends {
+		if complete == backend {
+			return true
+		}
+	}
+	return false
+}
+
+// PoolDetail holds the verbose state of a single pool: capacity, health,
+// scrub, vdev, and dataset information.
+type PoolDetail struct {
+	DisplayName string     `json:"displayName,omitempty"`
+	Raw         bool       `json:"raw,omitempty"`
+	Name        string     `json:"name"`
+	Health      string     `json:"health,omitempty"`
+	Size        uint64     `json:"size,omitempty"`  // bytes
+	Alloc       uint64     `json:"alloc,omitempty"` // bytes
+	Free        uint64     `json:"free,omitempty"`  // bytes
+	Scrub       *Scrub     `json:"scrub,omitempty"`
+	Vdevs       []*Vdev    `json:"vdevs,omitempty"`
+	Datasets    []*Dataset `json:"datasets,omitempty"`
+}
+
+// Scrub holds the scrub (or resilver) status of a pool.
+type Scrub struct {
+	State    string `json:"state,omitempty"` // NONE, SCANNING, FINISHED, CANCELED
+	Progress string `json:"progress,omitempty"`
+	Errors   uint64 `json:"errors,omitempty"`
+}
+
+// Vdev is a single vdev (mirror, raidz, or leaf disk) with error counters.
+type Vdev struct {
+	Name         string `json:"name"`
+	State        string `json:"state,omitempty"`
+	ReadErrs     uint64 `json:"readErrs,omitempty"`
+	WriteErrs    uint64 `json:"writeErrs,omitempty"`
+	ChecksumErrs uint64 `json:"checksumErrs,omitempty"`
+}
+
+// Dataset is a single ZFS dataset with usage information.
+type Dataset struct {
+	Name       string `json:"name"`
+	Used       uint64 `json:"used,omitempty"`
+	Avail      uint64 `json:"avail,omitempty"`
+	Mountpoint string `json:"mount,omitempty"`
+}

internal/hub/api.go

@@ -2,13 +2,17 @@ package hub
 
 import (
 	"context"
+	"fmt"
+	"log/slog"
+	"net"
 	"net/http"
+	"net/netip"
 	"regexp"
 	"strings"
 	"time"
+	"uuid"
 
 	"github.com/blang/semver"
-	"github.com/google/uuid"
 	"github.com/henrygd/beszel"
 	"github.com/henrygd/beszel/internal/alerts"
 	"github.com/henrygd/beszel/internal/ghupdate"
@@ -78,12 +82,81 @@ func (h *Hub) registerMiddlewares(se *core.ServeEvent) {
 	}
 	// authenticate with trusted header
 	if trustedHeader, _ := utils.GetEnv("TRUSTED_AUTH_HEADER"); trustedHeader != "" {
+		// only honor the header from these peers, if set
+		trustedProxies, restricted := parseTrustedProxies()
 		se.Router.BindFunc(func(e *core.RequestEvent) error {
+			if restricted && !isTrustedProxy(trustedProxies, e.Request.RemoteAddr) {
+				return e.Next()
+			}
 			return authorizeRequestWithEmail(e, e.Request.Header.Get(trustedHeader))
 		})
 	}
 }
 
+// parseTrustedProxies reads TRUSTED_PROXY_IPS (comma-separated IPs or CIDRs).
+// restricted is false when the variable is unset or empty, meaning the trusted
+// header is accepted from any peer. Invalid entries are skipped with a warning,
+// so a typo narrows the allowlist rather than widening it.
+func parseTrustedProxies() (prefixes []netip.Prefix, restricted bool) {
+	value, _ := utils.GetEnv("TRUSTED_PROXY_IPS")
+	if value == "" {
+		return nil, false
+	}
+	for entry := range strings.SplitSeq(value, ",") {
+		entry = strings.TrimSpace(entry)
+		if entry == "" {
+			continue
+		}
+		if prefix, err := parseProxyPrefix(entry); err == nil {
+			prefixes = append(prefixes, prefix)
+		} else {
+			slog.Warn("Ignoring invalid TRUSTED_PROXY_IPS entry", "entry", entry)
+		}
+	}
+	return prefixes, true
+}
+
+// parseProxyPrefix parses an IP or CIDR into a masked prefix. IPv4-mapped IPv6
+// entries are converted to IPv4 so they match IPv4 peers.
+func parseProxyPrefix(entry string) (netip.Prefix, error) {
+	prefix, err := netip.ParsePrefix(entry)
+	if err != nil {
+		addr, err := netip.ParseAddr(entry)
+		if err != nil {
+			return netip.Prefix{}, err
+		}
+		addr = addr.Unmap()
+		return netip.PrefixFrom(addr, addr.BitLen()), nil
+	}
+	if prefix.Addr().Is4In6() {
+		if prefix.Bits() < 96 {
+			return netip.Prefix{}, fmt.Errorf("%s covers more than the IPv4-mapped range", entry)
+		}
+		prefix = netip.PrefixFrom(prefix.Addr().Unmap(), prefix.Bits()-96)
+	}
+	return prefix.Masked(), nil
+}
+
+// isTrustedProxy reports whether the peer address of a request (host:port) is
+// within one of the prefixes.
+func isTrustedProxy(prefixes []netip.Prefix, remoteAddr string) bool {
+	host, _, err := net.SplitHostPort(remoteAddr)
+	if err != nil {
+		host = remoteAddr
+	}
+	addr, err := netip.ParseAddr(host)
+	if err != nil {
+		return false
+	}
+	addr = addr.Unmap().WithZone("")
+	for _, prefix := range prefixes {
+		if prefix.Contains(addr) {
+			return true
+		}
+	}
+	return false
+}
+
 // registerApiRoutes registers custom API routes
 func (h *Hub) registerApiRoutes(se *core.ServeEvent) error {
 	// auth protected routes
@@ -125,6 +198,8 @@ func (h *Hub) registerApiRoutes(se *core.ServeEvent) error {
 	apiAuth.DELETE("/user-alerts", alerts.DeleteUserAlerts)
 	// refresh SMART devices for a system
 	apiAuth.POST("/smart/refresh", h.refreshSmartData).BindFunc(excludeReadOnlyRole)
+	// refresh ZFS pool details for a system
+	apiAuth.POST("/zfs/refresh", h.refreshZfsData).BindFunc(excludeReadOnlyRole)
 	// get systemd service details
 	apiAuth.GET("/systemd/info", h.getSystemdInfo)
 	// /containers routes
@@ -389,3 +464,23 @@ func (h *Hub) refreshSmartData(e *core.RequestEvent) error {
 
 	return e.JSON(http.StatusOK, map[string]string{"status": "ok"})
 }
+
+// refreshZfsData handles POST /api/beszel/zfs/refresh requests
+// Fetches fresh ZFS detail data from the agent and updates the collection
+func (h *Hub) refreshZfsData(e *core.RequestEvent) error {
+	systemID := e.Request.URL.Query().Get("system")
+	if systemID == "" {
+		return e.BadRequestError("Invalid system parameter", nil)
+	}
+
+	system, err := h.sm.GetSystem(systemID)
+	if err != nil || !system.HasUser(e.App, e.Auth) {
+		return e.NotFoundError("", nil)
+	}
+
+	if err := system.FetchAndSaveZfsPools(true); err != nil {
+		return e.InternalServerError("", err)
+	}
+
+	return e.JSON(http.StatusOK, map[string]string{"status": "ok"})
+}

internal/hub/api_test.go

@@ -6,11 +6,16 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"net/http/httptest"
+	"sort"
 	"testing"
+	"time"
 
 	beszelTests "github.com/henrygd/beszel/internal/tests"
 
 	"github.com/henrygd/beszel/internal/migrations"
+	"github.com/pocketbase/dbx"
+	"github.com/pocketbase/pocketbase/apis"
 	"github.com/pocketbase/pocketbase/core"
 	pbTests "github.com/pocketbase/pocketbase/tests"
 	"github.com/stretchr/testify/require"
@@ -25,6 +30,59 @@ func jsonReader(v any) io.Reader {
 	return bytes.NewReader(data)
 }
 
+type gatedReader struct {
+	data    []byte
+	started chan struct{}
+	release chan struct{}
+	offset  int
+}
+
+func (r *gatedReader) Read(p []byte) (int, error) {
+	if r.offset == 0 {
+		close(r.started)
+		<-r.release
+	}
+	if r.offset >= len(r.data) {
+		return 0, io.EOF
+	}
+	n := copy(p, r.data[r.offset:])
+	r.offset += n
+	return n, nil
+}
+
+func firstUserTestMux(t *testing.T) (*beszelTests.TestHub, http.Handler) {
+	t.Helper()
+	hub, err := beszelTests.NewTestHub(t.TempDir())
+	require.NoError(t, err)
+	_ = hub.StartHub()
+
+	router, err := apis.NewRouter(hub.TestApp)
+	require.NoError(t, err)
+	serveEvent := &core.ServeEvent{App: hub.TestApp, Router: router}
+
+	var handler http.Handler
+	err = hub.TestApp.OnServe().Trigger(serveEvent, func(e *core.ServeEvent) error {
+		var buildErr error
+		handler, buildErr = e.Router.BuildMux()
+		return buildErr
+	})
+	require.NoError(t, err)
+	require.NotNil(t, handler)
+	return hub, handler
+}
+
+func postFirstUser(handler http.Handler, email string) *httptest.ResponseRecorder {
+	body, _ := json.Marshal(map[string]string{
+		"email":    email,
+		"password": "password123",
+	})
+	req := httptest.NewRequest(http.MethodPost, "/api/beszel/create-user", bytes.NewReader(body))
+	req.Header.Set("Content-Type", "application/json")
+	recorder := httptest.NewRecorder()
+	handler.ServeHTTP(recorder, req)
+	return recorder
+}
+
 func TestApiRoutesAuthentication(t *testing.T) {
 	hub, user := beszelTests.GetHubWithUser(t)
 	defer hub.Cleanup()
@@ -55,7 +113,7 @@ func TestApiRoutesAuthentication(t *testing.T) {
 	// Create test system
 	system, err := beszelTests.CreateRecord(hub, "systems", map[string]any{
 		"name":  "test-system",
-		"users": []string{user.Id},
+		"users": []string{user.Id, readOnlyUser.Id},
 		"host":  "127.0.0.1",
 	})
 	require.NoError(t, err, "Failed to create test system")
@@ -277,6 +335,24 @@ func TestApiRoutesAuthentication(t *testing.T) {
 				"systems": []string{system.Id},
 			}),
 		},
+		{
+			Name:   "POST /user-alerts - readonly user can create own alert",
+			Method: http.MethodPost,
+			URL:    "/api/beszel/user-alerts",
+			Headers: map[string]string{
+				"Authorization": readOnlyUserToken,
+			},
+			ExpectedStatus:  200,
+			ExpectedContent: []string{"\"success\":true"},
+			TestAppFactory:  testAppFactory,
+			Body: jsonReader(map[string]any{
+				"name": "CPU", "value": 80, "min": 10, "systems": []string{system.Id},
+			}),
+			AfterTestFunc: func(t testing.TB, app *pbTests.TestApp, res *http.Response) {
+				alerts, _ := app.CountRecords("alerts", dbx.HashExp{"user": readOnlyUser.Id})
+				require.EqualValues(t, 1, alerts)
+			},
+		},
 		{
 			Name:            "DELETE /user-alerts - no auth should fail",
 			Method:          http.MethodDelete,
@@ -314,6 +390,29 @@ func TestApiRoutesAuthentication(t *testing.T) {
 				})
 			},
 		},
+		{
+			Name:   "DELETE /user-alerts - readonly user can delete own alert",
+			Method: http.MethodDelete,
+			URL:    "/api/beszel/user-alerts",
+			Headers: map[string]string{
+				"Authorization": readOnlyUserToken,
+			},
+			ExpectedStatus:  200,
+			ExpectedContent: []string{"\"count\":1", "\"success\":true"},
+			TestAppFactory:  testAppFactory,
+			Body: jsonReader(map[string]any{
+				"name": "CPU", "systems": []string{system.Id},
+			}),
+			BeforeTestFunc: func(t testing.TB, app *pbTests.TestApp, e *core.ServeEvent) {
+				beszelTests.CreateRecord(app, "alerts", map[string]any{
+					"name": "CPU", "system": system.Id, "user": readOnlyUser.Id, "value": 80,
+				})
+			},
+			AfterTestFunc: func(t testing.TB, app *pbTests.TestApp, res *http.Response) {
+				alerts, _ := app.CountRecords("alerts", dbx.HashExp{"user": readOnlyUser.Id})
+				require.Zero(t, alerts)
+			},
+		},
 		{
 			Name:            "GET /containers/logs - no auth should fail",
 			Method:          http.MethodGet,
@@ -747,6 +846,87 @@ func TestFirstUserCreation(t *testing.T) {
 	})
 }
 
+func TestFirstUserBootstrapAtomicity(t *testing.T) {
+	t.Run("concurrent complete requests produce exactly one winner", func(t *testing.T) {
+		hub, handler := firstUserTestMux(t)
+		defer hub.Cleanup()
+
+		start := make(chan struct{})
+		statuses := make(chan int, 2)
+		for _, email := range []string{"first@example.com", "second@example.com"} {
+			go func(email string) {
+				<-start
+				statuses <- postFirstUser(handler, email).Code
+			}(email)
+		}
+		close(start)
+
+		got := []int{<-statuses, <-statuses}
+		sort.Ints(got)
+		require.Equal(t, []int{http.StatusOK, http.StatusForbidden}, got)
+
+		users, err := hub.FindAllRecords("users")
+		require.NoError(t, err)
+		require.Len(t, users, 1)
+		superusers, err := hub.FindAllRecords(core.CollectionNameSuperusers)
+		require.NoError(t, err)
+		require.Len(t, superusers, 1)
+		require.NotEqual(t, migrations.TempAdminEmail, superusers[0].Email())
+	})
+
+	t.Run("partial body cannot retain stale bootstrap authorization", func(t *testing.T) {
+		hub, handler := firstUserTestMux(t)
+		defer hub.Cleanup()
+
+		body, err := json.Marshal(map[string]string{
+			"email":    "parked@example.com",
+			"password": "password123",
+		})
+		require.NoError(t, err)
+		gated := &gatedReader{
+			data:    body,
+			started: make(chan struct{}),
+			release: make(chan struct{}),
+		}
+		parkedRequest := httptest.NewRequest(http.MethodPost, "/api/beszel/create-user", gated)
+		parkedRequest.Header.Set("Content-Type", "application/json")
+		parkedRecorder := httptest.NewRecorder()
+		parkedDone := make(chan struct{})
+		go func() {
+			handler.ServeHTTP(parkedRecorder, parkedRequest)
+			close(parkedDone)
+		}()
+
+		select {
+		case <-gated.started:
+		case <-time.After(2 * time.Second):
+			t.Fatal("parked request did not begin reading its body")
+		}
+
+		operatorRecorder := postFirstUser(handler, "operator@example.com")
+		require.Equal(t, http.StatusOK, operatorRecorder.Code)
+		lateRecorder := postFirstUser(handler, "late@example.com")
+		require.Equal(t, http.StatusForbidden, lateRecorder.Code)
+
+		close(gated.release)
+		select {
+		case <-parkedDone:
+		case <-time.After(2 * time.Second):
+			t.Fatal("parked request did not finish")
+		}
+		require.Equal(t, http.StatusForbidden, parkedRecorder.Code)
+
+		users, err := hub.FindAllRecords("users")
+		require.NoError(t, err)
+		require.Len(t, users, 1)
+		require.Equal(t, "operator@example.com", users[0].Email())
+		superusers, err := hub.FindAllRecords(core.CollectionNameSuperusers)
+		require.NoError(t, err)
+		require.Len(t, superusers, 1)
+		require.Equal(t, "operator@example.com", superusers[0].Email())
+	})
+}
+
 func TestCreateUserEndpointAvailability(t *testing.T) {
 	t.Run("CreateUserEndpoint available when no users exist", func(t *testing.T) {
 		hub, _ := beszelTests.NewTestHub(t.TempDir())
@@ -927,6 +1107,79 @@ func TestTrustedHeaderMiddleware(t *testing.T) {
 	}
 }
 
+func TestTrustedHeaderProxyAllowlist(t *testing.T) {
+	var hubs []*beszelTests.TestHub
+
+	defer func() {
+		for _, hub := range hubs {
+			hub.Cleanup()
+		}
+	}()
+
+	testAppFactory := func(t testing.TB) *pbTests.TestApp {
+		hub, _ := beszelTests.NewTestHub(t.TempDir())
+		hubs = append(hubs, hub)
+		hub.StartHub()
+		return hub.TestApp
+	}
+
+	// httptest requests arrive from 192.0.2.1:1234
+	testCases := []struct {
+		name            string
+		proxies         string
+		expectedStatus  int
+		expectedContent []string
+	}{
+		{
+			name:            "peer inside an allowed range",
+			proxies:         "10.0.0.0/8, 192.0.2.0/24",
+			expectedStatus:  200,
+			expectedContent: []string{"\"key\":", "\"v\":"},
+		},
+		{
+			name:            "peer is the listed address",
+			proxies:         "192.0.2.1",
+			expectedStatus:  200,
+			expectedContent: []string{"\"key\":", "\"v\":"},
+		},
+		{
+			name:            "peer outside the allowlist",
+			proxies:         "10.0.0.0/8",
+			expectedStatus:  401,
+			expectedContent: []string{"requires valid"},
+		},
+		{
+			name:            "allowlist with no valid entry",
+			proxies:         "proxy.internal",
+			expectedStatus:  401,
+			expectedContent: []string{"requires valid"},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Setenv("TRUSTED_AUTH_HEADER", "X-Beszel-Trusted")
+			t.Setenv("TRUSTED_PROXY_IPS", tc.proxies)
+
+			scenario := beszelTests.ApiScenario{
+				Name:   "GET /getkey - with trusted header",
+				Method: http.MethodGet,
+				URL:    "/api/beszel/getkey",
+				Headers: map[string]string{
+					"X-Beszel-Trusted": "user@test.com",
+				},
+				ExpectedStatus:  tc.expectedStatus,
+				ExpectedContent: tc.expectedContent,
+				TestAppFactory:  testAppFactory,
+				BeforeTestFunc: func(t testing.TB, app *pbTests.TestApp, e *core.ServeEvent) {
+					beszelTests.CreateUser(app, "user@test.com", "password123")
+				},
+			}
+			scenario.Test(t)
+		})
+	}
+}
+
 func TestUpdateEndpoint(t *testing.T) {
 	t.Setenv("CHECK_UPDATES", "true")
 

internal/hub/collections.go

@@ -91,10 +91,16 @@ func setCollectionAuthSettings(app core.App) error {
 	}); err != nil {
 		return err
 	}
+	if err := applyCollectionRules(app, []string{"zfs_pools"}, collectionRules{
+		list: &systemScopedReadRule,
+		view: &systemScopedReadRule,
+	}); err != nil {
+		return err
+	}
 
 	if err := applyCollectionRules(app, []string{"fingerprints"}, collectionRules{
-		list:   &systemScopedReadRule,
+		list:   &systemScopedWriteRule,
-		view:   &systemScopedReadRule,
+		view:   &systemScopedWriteRule,
 		create: &systemScopedWriteRule,
 		update: &systemScopedWriteRule,
 		delete: &systemScopedWriteRule,

internal/hub/collections_test.go

@@ -50,6 +50,13 @@ func TestCollectionRulesDefault(t *testing.T) {
 	assert.Equal(t, isUserMatchesUser, *alertsCollection.CreateRule)
 	assert.Equal(t, isUserMatchesUser, *alertsCollection.UpdateRule)
 	assert.Equal(t, isUserMatchesUser, *alertsCollection.DeleteRule)
+	alertNames := alertsCollection.Fields.GetByName("name").(*core.SelectField).Values
+	for _, name := range []string{"CPUIOWait", "CPUSteal"} {
+		assert.Contains(t, alertNames, name)
+	}
+	for _, name := range []string{"CPUSystem", "CPUUser", "CPUIdle", "CPUOther"} {
+		assert.NotContains(t, alertNames, name)
+	}
 
 	// alerts_history collection
 	alertsHistoryCollection, err := hub.FindCollectionByNameOrId("alerts_history")
@@ -81,8 +88,8 @@ func TestCollectionRulesDefault(t *testing.T) {
 	// fingerprints collection
 	fingerprintsCollection, err := hub.FindCollectionByNameOrId("fingerprints")
 	require.NoError(t, err, "Failed to find fingerprints collection")
-	assert.Equal(t, isUserInSystemUsers, *fingerprintsCollection.ListRule)
+	assert.Equal(t, isUserInSystemUsersNotReadonly, *fingerprintsCollection.ListRule)
-	assert.Equal(t, isUserInSystemUsers, *fingerprintsCollection.ViewRule)
+	assert.Equal(t, isUserInSystemUsersNotReadonly, *fingerprintsCollection.ViewRule)
 	assert.Equal(t, isUserInSystemUsersNotReadonly, *fingerprintsCollection.CreateRule)
 	assert.Equal(t, isUserInSystemUsersNotReadonly, *fingerprintsCollection.UpdateRule)
 	assert.Equal(t, isUserInSystemUsersNotReadonly, *fingerprintsCollection.DeleteRule)
@@ -209,8 +216,8 @@ func TestCollectionRulesShareAllSystems(t *testing.T) {
 	// fingerprints collection
 	fingerprintsCollection, err := hub.FindCollectionByNameOrId("fingerprints")
 	require.NoError(t, err, "Failed to find fingerprints collection")
-	assert.Equal(t, isUser, *fingerprintsCollection.ListRule)
+	assert.Equal(t, isUserNotReadonly, *fingerprintsCollection.ListRule)
-	assert.Equal(t, isUser, *fingerprintsCollection.ViewRule)
+	assert.Equal(t, isUserNotReadonly, *fingerprintsCollection.ViewRule)
 	assert.Equal(t, isUserNotReadonly, *fingerprintsCollection.CreateRule)
 	assert.Equal(t, isUserNotReadonly, *fingerprintsCollection.UpdateRule)
 	assert.Equal(t, isUserNotReadonly, *fingerprintsCollection.DeleteRule)
@@ -357,6 +364,13 @@ func TestApiCollectionsAuthRules(t *testing.T) {
 		"host":  "127.0.0.2",
 	})
 
+	userOneAlert, _ := beszelTests.CreateRecord(hub, "alerts", map[string]any{
+		"name": "CPU", "system": userOneSystem.Id, "user": user1.Id, "value": 80,
+	})
+	userTwoAlert, _ := beszelTests.CreateRecord(hub, "alerts", map[string]any{
+		"name": "CPU", "system": userTwoSystem.Id, "user": user2.Id, "value": 80,
+	})
+
 	userRecords, _ := hub.CountRecords("users")
 	assert.EqualValues(t, 3, userRecords, "all users should be created")
 
@@ -368,6 +382,30 @@ func TestApiCollectionsAuthRules(t *testing.T) {
 	}
 
 	scenarios := []beszelTests.ApiScenario{
+		{
+			Name:   "Users can only list their own alerts",
+			Method: http.MethodGet,
+			URL:    "/api/collections/alerts/records",
+			Headers: map[string]string{
+				"Authorization": user1Token,
+			},
+			ExpectedStatus:     200,
+			ExpectedContent:    []string{userOneAlert.Id},
+			NotExpectedContent: []string{userTwoAlert.Id},
+			TestAppFactory:     testAppFactory,
+		},
+		{
+			Name:   "Users cannot view another user's alert by id",
+			Method: http.MethodGet,
+			URL:    fmt.Sprintf("/api/collections/alerts/records/%s", userTwoAlert.Id),
+			Headers: map[string]string{
+				"Authorization": user1Token,
+			},
+			ExpectedStatus:     403,
+			ExpectedContent:    []string{"Only superusers"},
+			NotExpectedContent: []string{userTwoAlert.Id},
+			TestAppFactory:     testAppFactory,
+		},
 		{
 			Name:               "Unauthorized user cannot list systems",
 			Method:             http.MethodGet,

internal/hub/config/config.go

@@ -6,8 +6,8 @@ import (
 	"log"
 	"os"
 	"path/filepath"
+	"uuid"
 
-	"github.com/google/uuid"
 	"github.com/henrygd/beszel/internal/entities/system"
 
 	"github.com/pocketbase/dbx"

internal/hub/hub.go

@@ -122,6 +122,8 @@ func (h *Hub) initialize(app core.App) error {
 	settings := app.Settings()
 	// batch requests (for alerts)
 	settings.Batch.Enabled = true
+	settings.Batch.MaxRequests = 100
+	settings.Batch.MaxBodySize = 1 << 20 // 1 MiB
 	// set URL if APP_URL env is set
 	if appURL, isSet := utils.GetEnv("APP_URL"); isSet {
 		h.appURL = appURL

internal/hub/systems/container_records_test.go

@@ -0,0 +1,46 @@
+//go:build testing
+
+package systems
+
+import (
+	"testing"
+
+	"github.com/henrygd/beszel/internal/entities/container"
+	"github.com/pocketbase/dbx"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCreateContainerRecordsPersistsImageUpdateAvailability(t *testing.T) {
+	_, app := newTestSystemWithHub(t)
+
+	const (
+		systemID    = "system123"
+		containerID = "abcdef123456"
+		image       = "nginx:latest"
+	)
+
+	data := &container.Stats{
+		Id:              containerID,
+		Name:            "web",
+		Image:           image,
+		UpdateAvailable: true,
+	}
+	require.NoError(t, createContainerRecords(app, []*container.Stats{data}, systemID))
+
+	var record struct {
+		Image           string `db:"image"`
+		UpdateAvailable bool   `db:"updatable"`
+	}
+	require.NoError(t, app.DB().Select("image", "updatable").From("containers").
+		Where(dbx.HashExp{"id": containerID}).One(&record))
+	assert.Equal(t, image, record.Image)
+	assert.True(t, record.UpdateAvailable)
+
+	data.UpdateAvailable = false
+	require.NoError(t, createContainerRecords(app, []*container.Stats{data}, systemID))
+	require.NoError(t, app.DB().Select("image", "updatable").From("containers").
+		Where(dbx.HashExp{"id": containerID}).One(&record))
+	assert.Equal(t, image, record.Image)
+	assert.False(t, record.UpdateAvailable)
+}

internal/hub/systems/ssh_timeout_test.go

@@ -4,11 +4,13 @@ package systems
 
 import (
 	"errors"
+	"sync"
 	"testing"
 	"testing/synctest"
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"golang.org/x/crypto/ssh"
 )
 
 // TestRunWithTimeout covers the guard added for issue #2041: the per-system SSH
@@ -54,3 +56,38 @@ func TestRunWithTimeout(t *testing.T) {
 		})
 	})
 }
+
+// closedConn stands in for a connection whose peer has gone away: opening a
+// channel fails rather than succeeding, which is what NewSession does on a
+// client that closeSSHConnection has already closed.
+type closedConn struct{ ssh.Conn }
+
+func (closedConn) OpenChannel(string, []byte) (ssh.Channel, <-chan *ssh.Request, error) {
+	return nil, nil, errors.New("use of closed network connection")
+}
+
+func (closedConn) Close() error { return nil }
+
+// TestCreateSessionDuringClose covers issue #2157: the background SMART fetch
+// creates a session while the updater can be tearing the same connection down,
+// so session creation must not read the client field after it is cleared.
+func TestCreateSessionDuringClose(t *testing.T) {
+	for range 500 {
+		sys := &System{ctx: t.Context()}
+		sys.client.Store(&ssh.Client{Conn: closedConn{}})
+
+		var wg sync.WaitGroup
+		wg.Add(2)
+		go func() {
+			defer wg.Done()
+			session, err := sys.createSessionWithTimeout(time.Second)
+			assert.Nil(t, session)
+			assert.Error(t, err, "a closed connection must surface an error, not a session")
+		}()
+		go func() {
+			defer wg.Done()
+			sys.closeSSHConnection()
+		}()
+		wg.Wait()
+	}
+}

internal/hub/systems/system.go

@@ -21,6 +21,7 @@ import (
 	"github.com/henrygd/beszel/internal/entities/smart"
 	"github.com/henrygd/beszel/internal/entities/system"
 	"github.com/henrygd/beszel/internal/entities/systemd"
+	"github.com/henrygd/beszel/internal/entities/zfs"
 
 	"github.com/henrygd/beszel"
 
@@ -33,22 +34,24 @@ import (
 )
 
 type System struct {
-	Id             string                  `db:"id"`
+	Id             string                     `db:"id"`
-	Host           string                  `db:"host"`
+	Host           string                     `db:"host"`
-	Port           string                  `db:"port"`
+	Port           string                     `db:"port"`
-	Status         string                  `db:"status"`
+	Status         string                     `db:"status"`
-	manager        *SystemManager          // Manager that this system belongs to
+	manager        *SystemManager             // Manager that this system belongs to
-	client         *ssh.Client             // SSH client for fetching data
+	client         atomic.Pointer[ssh.Client] // SSH client for fetching data
-	sshTransport   *transport.SSHTransport // SSH transport for requests
+	sshTransport   *transport.SSHTransport    // SSH transport for requests
-	data           *system.CombinedData    // system data from agent
+	data           *system.CombinedData       // system data from agent
-	ctx            context.Context         // Context for stopping the updater
+	ctx            context.Context            // Context for stopping the updater
-	cancel         context.CancelFunc      // Stops and removes system from updater
+	cancel         context.CancelFunc         // Stops and removes system from updater
-	WsConn         *ws.WsConn              // Handler for agent WebSocket connection
+	WsConn         *ws.WsConn                 // Handler for agent WebSocket connection
-	agentVersion   semver.Version          // Agent version
+	agentVersion   semver.Version             // Agent version
-	updateTicker   *time.Ticker            // Ticker for updating the system
+	updateTicker   *time.Ticker               // Ticker for updating the system
-	detailsFetched atomic.Bool             // True if static system details have been fetched and saved
+	detailsFetched atomic.Bool                // True if static system details have been fetched and saved
-	smartFetching  atomic.Bool             // True if SMART devices are currently being fetched
+	smartFetching  atomic.Bool                // True if SMART devices are currently being fetched
-	smartInterval  time.Duration           // Interval for periodic SMART data updates
+	smartInterval  time.Duration              // Interval for periodic SMART data updates
+	zfsFetching    atomic.Bool                // True if ZFS pools are currently being fetched
+	zfsInterval    time.Duration              // Interval for periodic ZFS detail data updates
 }
 
 func (sm *SystemManager) NewSystem(systemId string) *System {
@@ -154,6 +157,12 @@ func (sys *System) update() error {
 			// to prevent premature expiration leading to new fetch if interval is different.
 			sys.manager.smartFetchMap.UpdateExpiration(sys.Id, sys.smartInterval+time.Minute)
 		}
+		// update zfs interval if it's set on the agent side
+		if data.Details.ZfsInterval > 0 {
+			sys.zfsInterval = data.Details.ZfsInterval
+			sys.manager.hub.Logger().Info("ZFS interval updated from agent details", "system", sys.Id, "interval", sys.zfsInterval.String())
+			sys.manager.zfsFetchMap.UpdateExpiration(sys.Id, sys.zfsInterval+time.Minute)
+		}
 	}
 
 	// Fetch and save SMART devices when system first comes online or at intervals
@@ -170,6 +179,20 @@ func (sys *System) update() error {
 		}
 	}
 
+	// Fetch and save ZFS pool details when system first comes online or at intervals
+	if backgroundZfsFetchEnabled() && sys.detailsFetched.Load() && sys.supportsZfsData() {
+		if sys.zfsInterval <= 0 {
+			sys.zfsInterval = time.Hour
+		}
+		if sys.shouldFetchZfs() && sys.zfsFetching.CompareAndSwap(false, true) {
+			sys.manager.hub.Logger().Info("ZFS fetch", "system", sys.Id, "interval", sys.zfsInterval.String())
+			go func() {
+				defer sys.zfsFetching.Store(false)
+				_ = sys.FetchAndSaveZfsPools(false)
+			}()
+		}
+	}
+
 	return err
 }
 
@@ -227,8 +250,10 @@ func (sys *System) createRecords(data *system.CombinedData) (*core.Record, error
 			}
 		}
 
-		// add new systemd_stats record
+		// Update systemd service records when the agent reports a fresh snapshot.
-		if len(data.SystemdServices) > 0 {
+		// The length check keeps snapshots from older agents working, while the
+		// explicit marker lets newer agents report that a fresh snapshot is empty.
+		if data.SystemdServicesUpdated || len(data.SystemdServices) > 0 {
 			if err := createSystemdStatsRecords(txApp, data.SystemdServices, sys.Id); err != nil {
 				return err
 			}
@@ -241,9 +266,21 @@ func (sys *System) createRecords(data *system.CombinedData) (*core.Record, error
 			}
 		}
 
+		if err := sys.syncZfsPoolHealth(txApp, data.Stats.ZfsPools); err != nil {
+			return err
+		}
+
 		// update system record (do this last because it triggers alerts and we need above records to be inserted first)
 		systemRecord.Set("status", up)
-		systemRecord.Set("info", data.Info)
+		// Distinguish an idle GPU from a system without GPU data (#2312)
+		info := struct {
+			system.Info
+			GpuPct *float64 `json:"g,omitempty"`
+		}{Info: data.Info}
+		if len(data.Stats.GPUData) > 0 {
+			info.GpuPct = &data.Info.GpuPct
+		}
+		systemRecord.Set("info", info)
 		if err := txApp.SaveNoValidate(systemRecord); err != nil {
 			return err
 		}
@@ -280,7 +317,10 @@ func createSystemDetailsRecord(app core.App, data *system.Details, systemId stri
 
 func createSystemdStatsRecords(app core.App, data []*systemd.Service, systemId string) error {
 	if len(data) == 0 {
-		return nil
+		_, err := app.DB().NewQuery(
+			"DELETE FROM systemd_services WHERE system = {:system}",
+		).Bind(dbx.Params{"system": systemId}).Execute()
+		return err
 	}
 	// shared params for all records
 	params := dbx.Params{
@@ -290,6 +330,11 @@ func createSystemdStatsRecords(app core.App, data []*systemd.Service, systemId s
 
 	valueStrings := make([]string, 0, len(data))
 	for i, service := range data {
+		// Agent payloads can contain null entries. Reject the snapshot before
+		// executing any queries so existing service records remain intact.
+		if service == nil {
+			return fmt.Errorf("null systemd service at index %d", i)
+		}
 		suffix := fmt.Sprintf("%d", i)
 		valueStrings = append(valueStrings, fmt.Sprintf("({:id%[1]s}, {:system}, {:name%[1]s}, {:state%[1]s}, {:sub%[1]s}, {:cpu%[1]s}, {:cpuPeak%[1]s}, {:memory%[1]s}, {:memPeak%[1]s}, {:updated})", suffix))
 		params["id"+suffix] = makeStableHashId(systemId, service.Name)
@@ -305,7 +350,16 @@ func createSystemdStatsRecords(app core.App, data []*systemd.Service, systemId s
 		"INSERT INTO systemd_services (id, system, name, state, sub, cpu, cpuPeak, memory, memPeak, updated) VALUES %s ON CONFLICT(id) DO UPDATE SET system = excluded.system, name = excluded.name, state = excluded.state, sub = excluded.sub, cpu = excluded.cpu, cpuPeak = excluded.cpuPeak, memory = excluded.memory, memPeak = excluded.memPeak, updated = excluded.updated",
 		strings.Join(valueStrings, ","),
 	)
-	_, err := app.DB().NewQuery(queryString).Bind(params).Execute()
+	if _, err := app.DB().NewQuery(queryString).Bind(params).Execute(); err != nil {
+		return err
+	}
+	// Remove services the agent no longer reports. Every row in this batch shares the
+	// same updated timestamp, so anything older no longer exists on the host. Left in
+	// place these rows survive until the retention sweep and surface inconsistently
+	// across the dashboard, the services table, and alerts.
+	_, err := app.DB().NewQuery(
+		"DELETE FROM systemd_services WHERE system = {:system} AND updated < {:updated}",
+	).Bind(dbx.Params{"system": systemId, "updated": params["updated"]}).Execute()
 	return err
 }
 
@@ -322,7 +376,7 @@ func createContainerRecords(app core.App, data []*container.Stats, systemId stri
 	valueStrings := make([]string, 0, len(data))
 	for i, container := range data {
 		suffix := fmt.Sprintf("%d", i)
-		valueStrings = append(valueStrings, fmt.Sprintf("({:id%[1]s}, {:system}, {:name%[1]s}, {:image%[1]s}, {:ports%[1]s}, {:status%[1]s}, {:health%[1]s}, {:cpu%[1]s}, {:memory%[1]s}, {:net%[1]s}, {:updated})", suffix))
+		valueStrings = append(valueStrings, fmt.Sprintf("({:id%[1]s}, {:system}, {:name%[1]s}, {:image%[1]s}, {:ports%[1]s}, {:status%[1]s}, {:health%[1]s}, {:cpu%[1]s}, {:memory%[1]s}, {:net%[1]s}, {:updateAvailable%[1]s}, {:updated})", suffix))
 		params["id"+suffix] = container.Id
 		params["name"+suffix] = container.Name
 		params["image"+suffix] = container.Image
@@ -336,9 +390,10 @@ func createContainerRecords(app core.App, data []*container.Stats, systemId stri
 			netBytes = uint64((container.NetworkSent + container.NetworkRecv) * 1024 * 1024)
 		}
 		params["net"+suffix] = netBytes
+		params["updateAvailable"+suffix] = container.UpdateAvailable
 	}
 	queryString := fmt.Sprintf(
-		"INSERT INTO containers (id, system, name, image, ports, status, health, cpu, memory, net, updated) VALUES %s ON CONFLICT(id) DO UPDATE SET system = excluded.system, name = excluded.name, image = excluded.image, ports = excluded.ports, status = excluded.status, health = excluded.health, cpu = excluded.cpu, memory = excluded.memory, net = excluded.net, updated = excluded.updated",
+		"INSERT INTO containers (id, system, name, image, ports, status, health, cpu, memory, net, updatable, updated) VALUES %s ON CONFLICT(id) DO UPDATE SET system = excluded.system, name = excluded.name, image = excluded.image, ports = excluded.ports, status = excluded.status, health = excluded.health, cpu = excluded.cpu, memory = excluded.memory, net = excluded.net, updatable = excluded.updatable, updated = excluded.updated",
 		strings.Join(valueStrings, ","),
 	)
 	_, err := app.DB().NewQuery(queryString).Bind(params).Execute()
@@ -434,7 +489,7 @@ func (sys *System) request(ctx context.Context, action common.WebSocketAction, r
 	err := sys.sshTransport.RequestWithRetry(ctx, action, req, dest, 1)
 	// Keep legacy SSH client/version fields in sync for other code paths.
 	if sys.sshTransport != nil {
-		sys.client = sys.sshTransport.GetClient()
+		sys.client.Store(sys.sshTransport.GetClient())
 		sys.agentVersion = sys.sshTransport.GetAgentVersion()
 	}
 	return err
@@ -476,8 +531,8 @@ func (sys *System) ensureSSHTransport() error {
 		})
 	}
 	// Sync client state with transport
-	if sys.client != nil {
+	if client := sys.client.Load(); client != nil {
-		sys.sshTransport.SetClient(sys.client)
+		sys.sshTransport.SetClient(client)
 		sys.sshTransport.SetAgentVersion(sys.agentVersion)
 	}
 	return nil
@@ -558,6 +613,15 @@ func (sys *System) FetchSmartDataFromAgent() (smart.SmartDataResponse, error) {
 	return result, err
 }
 
+// FetchZfsDataFromAgent fetches ZFS detail data from the agent.
+func (sys *System) FetchZfsDataFromAgent(force bool) (*zfs.ZfsData, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 60*time.Second)
+	defer cancel()
+	var result zfs.ZfsData
+	err := sys.request(ctx, common.GetZfsData, common.ZfsDataRequest{Force: force}, &result)
+	return &result, err
+}
+
 func makeStableHashId(strings ...string) string {
 	hash := fnv.New32a()
 	for _, str := range strings {
@@ -625,7 +689,7 @@ func (sys *System) fetchDataViaSSH(options common.DataRequestOptions) (*system.C
 // The operation can request a retry by returning true as the first return value.
 func (sys *System) runSSHOperation(timeout time.Duration, retries int, operation func(*ssh.Session) (bool, error)) error {
 	for attempt := 0; attempt <= retries; attempt++ {
-		if sys.client == nil || sys.Status == down {
+		if sys.client.Load() == nil || sys.Status == down {
 			if err := sys.createSSHClient(); err != nil {
 				return err
 			}
@@ -721,13 +785,14 @@ func (s *System) createSSHClient() error {
 	} else {
 		host = net.JoinHostPort(host, s.Port)
 	}
-	var err error
+	client, err := dialSSHWithKeepAlive(network, host, s.manager.sshConfig)
-	s.client, err = dialSSHWithKeepAlive(network, host, s.manager.sshConfig)
+	s.client.Store(client)
 	if err != nil {
 		return err
 	}
-	s.agentVersion, _ = extractAgentVersion(string(s.client.Conn.ServerVersion()))
+	s.agentVersion, _ = extractAgentVersion(string(client.Conn.ServerVersion()))
 	s.manager.resetFailedSmartFetchState(s.Id)
+	s.manager.resetFailedZfsFetchState(s.Id)
 	return nil
 }
 
@@ -762,7 +827,8 @@ func dialSSHWithKeepAlive(network, addr string, config *ssh.ClientConfig) (*ssh.
 // createSessionWithTimeout creates a new SSH session with a timeout to avoid hanging
 // in case of network issues
 func (sys *System) createSessionWithTimeout(timeout time.Duration) (*ssh.Session, error) {
-	if sys.client == nil {
+	client := sys.client.Load()
+	if client == nil {
 		return nil, fmt.Errorf("client not initialized")
 	}
 
@@ -773,7 +839,7 @@ func (sys *System) createSessionWithTimeout(timeout time.Duration) (*ssh.Session
 	errChan := make(chan error, 1)
 
 	go func() {
-		if session, err := sys.client.NewSession(); err != nil {
+		if session, err := client.NewSession(); err != nil {
 			errChan <- err
 		} else {
 			sessionChan <- session
@@ -795,9 +861,8 @@ func (sys *System) closeSSHConnection() {
 	if sys.sshTransport != nil {
 		sys.sshTransport.Close()
 	}
-	if sys.client != nil {
+	if client := sys.client.Swap(nil); client != nil {
-		sys.client.Close()
+		client.Close()
-		sys.client = nil
 	}
 }
 

internal/hub/systems/system_gpu_test.go

@@ -0,0 +1,44 @@
+//go:build testing
+
+package systems
+
+import (
+	"testing"
+
+	"github.com/henrygd/beszel/internal/entities/system"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCreateRecordsGPUUtilization(t *testing.T) {
+	sys, app := newTestSystemWithHub(t)
+	for _, tc := range []struct {
+		name  string
+		gpu   bool
+		usage float64
+	}{
+		{"no GPU", false, 0},
+		{"active GPU", true, 42.5},
+		{"idle GPU", true, 0},
+		{"GPU removed", false, 0},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			data := &system.CombinedData{Info: system.Info{GpuPct: tc.usage, Cpu: 12.5}}
+			if tc.gpu {
+				data.Stats.GPUData = map[string]system.GPUData{"0": {Name: "GPU", Usage: tc.usage}}
+			}
+			_, err := sys.createRecords(data)
+			require.NoError(t, err)
+			record, err := app.FindRecordById("systems", sys.Id)
+			require.NoError(t, err)
+			var info map[string]any
+			require.NoError(t, record.UnmarshalJSONField("info", &info))
+			assert.Equal(t, 12.5, info["cpu"])
+			if tc.gpu {
+				assert.Equal(t, tc.usage, info["g"])
+			} else {
+				assert.NotContains(t, info, "g")
+			}
+		})
+	}
+}

internal/hub/systems/system_manager.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"sync"
 	"time"
 
 	"github.com/henrygd/beszel/internal/hub/ws"
@@ -42,12 +43,17 @@ var errSystemExists = errors.New("system exists")
 // SystemManager manages a collection of monitored systems and their connections.
 // It handles system lifecycle, status updates, and maintains both SSH and WebSocket connections.
 type SystemManager struct {
-	hub           hubLike                               // Hub interface for database and alert operations
+	hub                 hubLike                               // Hub interface for database and alert operations
-	systems       *store.Store[string, *System]         // Thread-safe store of active systems
+	systems             *store.Store[string, *System]         // Thread-safe store of active systems
-	sshConfig     *ssh.ClientConfig                     // SSH client configuration for system connections
+	sshConfig           *ssh.ClientConfig                     // SSH client configuration for system connections
-	smartFetchMap *expirymap.ExpiryMap[smartFetchState] // Stores last SMART fetch time/result; TTL is only for cleanup
+	smartFetchMap       *expirymap.ExpiryMap[smartFetchState] // Stores last SMART fetch time/result; TTL is only for cleanup
-	ctx           context.Context                       // Cancelled when the app terminates
+	zfsFetchMap         *expirymap.ExpiryMap[zfsFetchState]   // Stores last ZFS fetch time/result; TTL is only for cleanup
-	cancel        context.CancelFunc                    // Cancels ctx and all child system contexts
+	realtimeMutex       sync.Mutex                            // Protects all realtime worker and subscription state
+	activeSubscriptions map[string]*subscriptionInfo          // Realtime subscriptions keyed by system ID
+	realtimeWorkerStop  chan struct{}                         // Stops the current realtime worker generation
+	realtimeWorkerRun   bool                                  // Whether a realtime worker has been started
+	ctx                 context.Context                       // Cancelled when the app terminates
+	cancel              context.CancelFunc                    // Cancels ctx and all child system contexts
 }
 
 // hubLike defines the interface requirements for the hub dependency.
@@ -57,16 +63,20 @@ type hubLike interface {
 	GetSSHKey(dataDir string) (ssh.Signer, error)
 	HandleSystemAlerts(systemRecord *core.Record, data *system.CombinedData) error
 	HandleStatusAlerts(status string, systemRecord *core.Record) error
+	HandleContainerAlerts(systemRecord *core.Record, data *system.CombinedData, fetchLogs func(containerID string) (string, error)) error
 	CancelPendingStatusAlerts(systemID string)
+	CancelPendingContainerAlerts(systemID string)
 }
 
 // NewSystemManager creates a new SystemManager instance with the provided hub.
 // The hub must implement the hubLike interface to provide database and alert functionality.
 func NewSystemManager(hub hubLike) *SystemManager {
 	sm := &SystemManager{
-		systems:       store.New(map[string]*System{}),
+		systems:             store.New(map[string]*System{}),
-		hub:           hub,
+		hub:                 hub,
-		smartFetchMap: expirymap.New[smartFetchState](time.Hour),
+		smartFetchMap:       expirymap.New[smartFetchState](time.Hour),
+		zfsFetchMap:         expirymap.New[zfsFetchState](time.Hour),
+		activeSubscriptions: make(map[string]*subscriptionInfo),
 	}
 	sm.ctx, sm.cancel = context.WithCancel(context.Background())
 	return sm
@@ -134,6 +144,7 @@ func (sm *SystemManager) bindEventHooks() {
 // onTerminate cancels SystemManager context on app shutdown
 func (sm *SystemManager) onTerminate(e *core.TerminateEvent) error {
 	sm.cancel()
+	sm.stopRealtimeWorker()
 	return e.Next()
 }
 
@@ -187,7 +198,7 @@ func (sm *SystemManager) onRecordUpdate(e *core.RecordEvent) error {
 // - paused: Closes SSH connection and deactivates alerts
 // - pending: Starts monitoring (reuses WebSocket if available)
 // - up: Triggers system alerts
-// - down: Triggers status change alerts
+// - down: Cancels pending container alerts and triggers status change alerts
 func (sm *SystemManager) onRecordAfterUpdateSuccess(e *core.RecordEvent) error {
 	newStatus := e.Record.GetString("status")
 	prevStatus := pending
@@ -205,6 +216,7 @@ func (sm *SystemManager) onRecordAfterUpdateSuccess(e *core.RecordEvent) error {
 		}
 		_ = deactivateAlerts(e.App, e.Record.Id)
 		sm.hub.CancelPendingStatusAlerts(e.Record.Id)
+		sm.hub.CancelPendingContainerAlerts(e.Record.Id)
 		return e.Next()
 	case pending:
 		// Resume monitoring, preferring existing WebSocket connection
@@ -218,6 +230,10 @@ func (sm *SystemManager) onRecordAfterUpdateSuccess(e *core.RecordEvent) error {
 		}
 		_ = deactivateAlerts(e.App, e.Record.Id)
 		return e.Next()
+	case down:
+		// Docker state is unknown while the system is unreachable. Do not let a
+		// delayed container-health alert fire from the last received snapshot.
+		sm.hub.CancelPendingContainerAlerts(e.Record.Id)
 	}
 
 	// Handle systems not in manager
@@ -230,6 +246,9 @@ func (sm *SystemManager) onRecordAfterUpdateSuccess(e *core.RecordEvent) error {
 		if err := sm.hub.HandleSystemAlerts(e.Record, system.data); err != nil {
 			e.App.Logger().Error("Error handling system alerts", "err", err)
 		}
+		if err := sm.hub.HandleContainerAlerts(e.Record, system.data, system.FetchContainerLogsFromAgent); err != nil {
+			e.App.Logger().Error("Error handling container alerts", "err", err)
+		}
 	}
 
 	// Trigger status change alerts for up/down transitions
@@ -343,6 +362,15 @@ func (sm *SystemManager) resetFailedSmartFetchState(systemID string) {
 	}
 }
 
+// resetFailedZfsFetchState clears only failed ZFS cooldown entries so a fresh
+// agent reconnect retries ZFS discovery immediately after configuration changes.
+func (sm *SystemManager) resetFailedZfsFetchState(systemID string) {
+	state, ok := sm.zfsFetchMap.GetOk(systemID)
+	if ok && !state.Successful {
+		sm.zfsFetchMap.Remove(systemID)
+	}
+}
+
 // createSSHClientConfig initializes the SSH client configuration for connecting to an agent's server
 func (sm *SystemManager) createSSHClientConfig() error {
 	privateKey, err := sm.hub.GetSSHKey("")

internal/hub/systems/system_realtime.go

@@ -3,25 +3,27 @@ package systems
 import (
 	"encoding/json"
 	"strings"
-	"sync"
 	"time"
 
 	"github.com/henrygd/beszel/internal/common"
+	"github.com/henrygd/beszel/internal/hub/utils"
+	"github.com/pocketbase/dbx"
+	"github.com/pocketbase/pocketbase/apis"
 	"github.com/pocketbase/pocketbase/core"
 	"github.com/pocketbase/pocketbase/tools/subscriptions"
 )
 
 type subscriptionInfo struct {
 	subscription     string
-	connectedClients uint8
+	connectedClients int
+	fetching         bool
 }
 
-var (
+type realtimeFetch struct {
-	activeSubscriptions = make(map[string]*subscriptionInfo)
+	systemID     string
-	workerRunning       bool
+	subscription string
-	tickerStopChan      chan struct{}
+	info         *subscriptionInfo
-	realtimeMutex       sync.Mutex
+}
-)
 
 // onRealtimeConnectRequest handles client connection events for realtime subscriptions.
 // It cleans up existing subscriptions when a client connects.
@@ -38,6 +40,19 @@ func (sm *SystemManager) onRealtimeConnectRequest(e *core.RealtimeConnectRequest
 // onRealtimeSubscribeRequest handles client subscription events for realtime metrics.
 // It tracks new subscriptions and unsubscriptions to manage the realtime worker lifecycle.
 func (sm *SystemManager) onRealtimeSubscribeRequest(e *core.RealtimeSubscribeRequestEvent) error {
+	// Parse with PocketBase's own subscription parser before changing the real
+	// client. Reject the entire request if any metrics target is inaccessible.
+	requested := subscriptions.NewDefaultClient()
+	requested.Subscribe(e.Subscriptions...)
+	for topic, options := range requested.Subscriptions() {
+		if !strings.HasPrefix(topic, "rt_metrics") {
+			continue
+		}
+		system, err := sm.GetSystem(options.Query["system"])
+		if err != nil || !system.HasUser(e.App, e.Auth) {
+			return e.NotFoundError("", nil)
+		}
+	}
 	oldSubs := e.Client.Subscriptions()
 	// after e.Next() is the result of the subscribe request
 	err := e.Next()
@@ -47,14 +62,7 @@ func (sm *SystemManager) onRealtimeSubscribeRequest(e *core.RealtimeSubscribeReq
 	for k, options := range newSubs {
 		if _, ok := oldSubs[k]; !ok {
 			if strings.HasPrefix(k, "rt_metrics") {
-				systemId := options.Query["system"]
+				sm.addRealtimeSubscription(options.Query["system"], k)
-				if _, ok := activeSubscriptions[systemId]; !ok {
-					activeSubscriptions[systemId] = &subscriptionInfo{
-						subscription: k,
-					}
-				}
-				activeSubscriptions[systemId].connectedClients += 1
-				sm.onRealtimeSubscriptionAdded()
 			}
 		}
 	}
@@ -68,72 +76,76 @@ func (sm *SystemManager) onRealtimeSubscribeRequest(e *core.RealtimeSubscribeReq
 	return err
 }
 
-// onRealtimeSubscriptionAdded initializes or starts the realtime worker when the first subscription is added.
+// addRealtimeSubscription tracks a subscriber and starts a worker if necessary.
-// It ensures only one worker runs at a time.
+func (sm *SystemManager) addRealtimeSubscription(systemID, subscription string) {
-func (sm *SystemManager) onRealtimeSubscriptionAdded() {
+	sm.realtimeMutex.Lock()
-	realtimeMutex.Lock()
+	defer sm.realtimeMutex.Unlock()
-	defer realtimeMutex.Unlock()
 
-	// Start the worker if it's not already running
+	if sm.activeSubscriptions == nil {
-	if !workerRunning {
+		sm.activeSubscriptions = make(map[string]*subscriptionInfo)
-		workerRunning = true
+	}
-		// Create a new stop channel for this worker instance
+	info, ok := sm.activeSubscriptions[systemID]
-		tickerStopChan = make(chan struct{})
+	if !ok {
-		go sm.startRealtimeWorker()
+		info = &subscriptionInfo{subscription: subscription}
+		sm.activeSubscriptions[systemID] = info
+	}
+	info.connectedClients++
+
+	if !sm.realtimeWorkerRun {
+		sm.realtimeWorkerRun = true
+		stop := make(chan struct{})
+		sm.realtimeWorkerStop = stop
+		go sm.startRealtimeWorker(stop)
 	}
 }
 
-// checkSubscriptions stops the realtime worker when there are no active subscriptions.
+// stopRealtimeWorker stops the current worker generation, if any.
-// This prevents unnecessary resource usage when no clients are listening for realtime data.
+func (sm *SystemManager) stopRealtimeWorker() {
-func (sm *SystemManager) checkSubscriptions() {
+	sm.realtimeMutex.Lock()
-	if !workerRunning || len(activeSubscriptions) > 0 {
+	defer sm.realtimeMutex.Unlock()
+	sm.stopRealtimeWorkerLocked()
+}
+
+func (sm *SystemManager) stopRealtimeWorkerLocked() {
+	if !sm.realtimeWorkerRun {
 		return
 	}
-
+	close(sm.realtimeWorkerStop)
-	realtimeMutex.Lock()
+	sm.realtimeWorkerStop = nil
-	defer realtimeMutex.Unlock()
+	sm.realtimeWorkerRun = false
-
-	// Signal the worker to stop
-	if tickerStopChan != nil {
-		select {
-		case tickerStopChan <- struct{}{}:
-		default:
-		}
-	}
-
-	// Mark worker as stopped (will be reset when next subscription comes in)
-	workerRunning = false
 }
 
 // removeRealtimeSubscription removes a realtime subscription and checks if the worker should be stopped.
 // It only processes subscriptions with the "rt_metrics" prefix and triggers cleanup when subscriptions are removed.
 func (sm *SystemManager) removeRealtimeSubscription(subscription string, options subscriptions.SubscriptionOptions) {
 	if strings.HasPrefix(subscription, "rt_metrics") {
-		systemId := options.Query["system"]
+		systemID := options.Query["system"]
-		if info, ok := activeSubscriptions[systemId]; ok {
+		sm.realtimeMutex.Lock()
-			info.connectedClients -= 1
+		if info, ok := sm.activeSubscriptions[systemID]; ok {
+			info.connectedClients--
 			if info.connectedClients <= 0 {
-				delete(activeSubscriptions, systemId)
+				delete(sm.activeSubscriptions, systemID)
 			}
 		}
-		sm.checkSubscriptions()
+		if len(sm.activeSubscriptions) == 0 {
+			sm.stopRealtimeWorkerLocked()
+		}
+		sm.realtimeMutex.Unlock()
 	}
 }
 
 // startRealtimeWorker runs the main loop for fetching realtime data from agents.
 // It continuously fetches system data and broadcasts it to subscribed clients via WebSocket.
-func (sm *SystemManager) startRealtimeWorker() {
+func (sm *SystemManager) startRealtimeWorker(stop <-chan struct{}) {
 	sm.fetchRealtimeDataAndNotify()
-	tick := time.Tick(1 * time.Second)
+	ticker := time.NewTicker(time.Second)
+	defer ticker.Stop()
 
 	for {
 		select {
-		case <-tickerStopChan:
+		case <-stop:
 			return
-		case <-tick:
+		case <-ticker.C:
-			if len(activeSubscriptions) == 0 {
-				return
-			}
 			sm.fetchRealtimeDataAndNotify()
 		}
 	}
@@ -141,27 +153,79 @@ func (sm *SystemManager) startRealtimeWorker() {
 
 // fetchRealtimeDataAndNotify fetches realtime data for all active subscriptions and notifies the clients.
 func (sm *SystemManager) fetchRealtimeDataAndNotify() {
-	for systemId, info := range activeSubscriptions {
+	for _, fetch := range sm.claimRealtimeFetches() {
-		system, err := sm.GetSystem(systemId)
+		system, err := sm.GetSystem(fetch.systemID)
 		if err != nil {
+			sm.finishRealtimeFetch(fetch)
 			continue
 		}
-		go func() {
+		go func(fetch realtimeFetch) {
+			defer sm.finishRealtimeFetch(fetch)
 			data, err := system.fetchDataFromAgent(common.DataRequestOptions{CacheTimeMs: 1000})
 			if err != nil {
 				return
 			}
 			bytes, err := json.Marshal(data)
 			if err == nil {
-				notify(sm.hub, info.subscription, bytes)
+				notify(sm.hub, system, fetch.subscription, bytes)
 			}
-		}()
+		}(fetch)
+	}
+}
+
+// claimRealtimeFetches takes a stable snapshot and marks each selected system as
+// in flight. Slow agents are skipped on later ticks until their fetch completes.
+func (sm *SystemManager) claimRealtimeFetches() []realtimeFetch {
+	sm.realtimeMutex.Lock()
+	defer sm.realtimeMutex.Unlock()
+
+	fetches := make([]realtimeFetch, 0, len(sm.activeSubscriptions))
+	for systemID, info := range sm.activeSubscriptions {
+		if info.fetching {
+			continue
+		}
+		info.fetching = true
+		fetches = append(fetches, realtimeFetch{
+			systemID:     systemID,
+			subscription: info.subscription,
+			info:         info,
+		})
+	}
+	return fetches
+}
+
+func (sm *SystemManager) finishRealtimeFetch(fetch realtimeFetch) {
+	sm.realtimeMutex.Lock()
+	defer sm.realtimeMutex.Unlock()
+	// A subscription may have been removed and recreated while the old request
+	// was running. Only release the exact entry claimed by this request.
+	if info := sm.activeSubscriptions[fetch.systemID]; info == fetch.info {
+		info.fetching = false
 	}
 }
 
 // notify broadcasts realtime data to all clients subscribed to a specific subscription.
-// It iterates through all connected clients and sends the data only to those with matching subscriptions.
+// Custom topics bypass collection rules, so check current access for every
-func notify(app core.App, subscription string, data []byte) error {
+// recipient, including clients whose authentication or membership was revoked.
+func notify(app core.App, system *System, subscription string, data []byte) error {
+	shareAll, _ := utils.GetEnv("SHARE_ALL_SYSTEMS")
+	members := make(map[string]struct{})
+	if shareAll != "true" {
+		// Refresh once per broadcast so membership changes take effect on the
+		// next update without querying the database for every recipient.
+		var recordData struct{ Users string }
+		if err := app.DB().NewQuery("SELECT users FROM systems WHERE id={:id}").
+			Bind(dbx.Params{"id": system.Id}).One(&recordData); err != nil {
+			return err
+		}
+		var userIDs []string
+		if err := json.Unmarshal([]byte(recordData.Users), &userIDs); err != nil {
+			return err
+		}
+		for _, id := range userIDs {
+			members[id] = struct{}{}
+		}
+	}
 	message := subscriptions.Message{
 		Name: subscription,
 		Data: data,
@@ -170,6 +234,13 @@ func notify(app core.App, subscription string, data []byte) error {
 		if !client.HasSubscription(subscription) {
 			continue
 		}
+		auth, _ := client.Get(apis.RealtimeClientAuthKey).(*core.Record)
+		if auth == nil {
+			continue
+		}
+		if _, member := members[auth.Id]; shareAll != "true" && !member {
+			continue
+		}
 		client.Send(message)
 	}
 	return nil

internal/hub/systems/system_realtime_test.go

@@ -0,0 +1,229 @@
+package systems
+
+import (
+	"testing"
+	"time"
+
+	"github.com/pocketbase/pocketbase/apis"
+	"github.com/pocketbase/pocketbase/core"
+	pbtests "github.com/pocketbase/pocketbase/tests"
+	"github.com/pocketbase/pocketbase/tools/hook"
+	"github.com/pocketbase/pocketbase/tools/store"
+	"github.com/pocketbase/pocketbase/tools/subscriptions"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestRealtimeAuthorization(t *testing.T) {
+	t.Setenv("SHARE_ALL_SYSTEMS", "false")
+	t.Setenv("BESZEL_HUB_SHARE_ALL_SYSTEMS", "")
+	app, err := pbtests.NewTestApp(t.TempDir())
+	require.NoError(t, err)
+	t.Cleanup(app.Cleanup)
+	_, err = app.DB().NewQuery(`CREATE TABLE IF NOT EXISTS systems (id TEXT PRIMARY KEY, users TEXT)`).Execute()
+	require.NoError(t, err)
+	_, err = app.DB().NewQuery(`INSERT INTO systems (id, users) VALUES ('target', '["member"]')`).Execute()
+	require.NoError(t, err)
+	member := core.NewRecord(core.NewAuthCollection("users"))
+	member.Id = "member"
+	outsider := core.NewRecord(member.Collection())
+	outsider.Id = "outsider"
+	system := &System{Id: "target"}
+	sm := newRealtimeTestManager()
+	sm.systems.Set(system.Id, system)
+	// Keep the lifecycle bookkeeping active without starting an agent worker.
+	sm.realtimeWorkerRun = true
+	sm.realtimeWorkerStop = make(chan struct{})
+	t.Cleanup(sm.stopRealtimeWorker)
+	topic := `rt_metrics?options={"query":{"system":"target"}}`
+
+	for _, tc := range []struct {
+		name    string
+		auth    *core.Record
+		topic   string
+		share   bool
+		allowed bool
+	}{
+		{"guest", nil, topic, false, false},
+		{"outsider", outsider, topic, false, false},
+		{"member", member, topic, false, true},
+		{"missing system", member, `rt_metrics`, false, false},
+		{"unknown system", member, `rt_metrics?options={"query":{"system":"missing"}}`, false, false},
+		{"malformed options", member, `rt_metrics?options=invalid`, false, false},
+		{"prefix variant", outsider, `rt_metrics_extra?options={"query":{"system":"target"}}`, false, false},
+		{"shared outsider", outsider, topic, true, true},
+		{"shared guest", nil, topic, true, false},
+		{"other topic", nil, "systems/*", false, true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			if tc.share {
+				t.Setenv("BESZEL_HUB_SHARE_ALL_SYSTEMS", "true")
+			}
+			client := subscriptions.NewDefaultClient()
+			client.Subscribe("existing")
+			e := &core.RealtimeSubscribeRequestEvent{
+				RequestEvent: &core.RequestEvent{App: app, Auth: tc.auth},
+				Client:       client, Subscriptions: []string{tc.topic},
+			}
+			called := false
+			h := &hook.Hook[*core.RealtimeSubscribeRequestEvent]{}
+			h.BindFunc(sm.onRealtimeSubscribeRequest)
+			err := h.Trigger(e, func(e *core.RealtimeSubscribeRequestEvent) error {
+				called = true
+				client.Unsubscribe()
+				client.Subscribe(e.Subscriptions...)
+				return nil
+			})
+			if tc.allowed {
+				require.NoError(t, err)
+				assert.True(t, called)
+			} else {
+				require.Error(t, err)
+				assert.False(t, called)
+				assert.True(t, client.HasSubscription("existing"))
+				assert.False(t, client.HasSubscription(tc.topic))
+			}
+		})
+	}
+
+	t.Run("broadcast checks current access", func(t *testing.T) {
+		client := subscriptions.NewDefaultClient()
+		client.Subscribe(topic)
+		app.SubscriptionsBroker().Register(client)
+		defer app.SubscriptionsBroker().Unregister(client.Id())
+		secondClient := subscriptions.NewDefaultClient()
+		secondClient.Subscribe(topic)
+		app.SubscriptionsBroker().Register(secondClient)
+		defer app.SubscriptionsBroker().Unregister(secondClient.Id())
+		check := func(auth *core.Record, allowed bool) {
+			t.Helper()
+			client.Set(apis.RealtimeClientAuthKey, auth)
+			secondClient.Set(apis.RealtimeClientAuthKey, auth)
+			done := make(chan struct{})
+			go func() {
+				notify(app, system, topic, []byte(`{"cpu":42}`))
+				close(done)
+			}()
+			// Even on failure, drain pending sends and join the broadcaster before
+			// unregistering clients, which closes their channels.
+			defer func() {
+				for {
+					select {
+					case <-client.Channel():
+					case <-secondClient.Channel():
+					case <-done:
+						return
+					}
+				}
+			}()
+			var received [2]int
+			timer := time.NewTimer(time.Second)
+			defer timer.Stop()
+			for {
+				select {
+				case msg := <-client.Channel():
+					received[0]++
+					assert.Equal(t, topic, msg.Name)
+				case msg := <-secondClient.Channel():
+					received[1]++
+					assert.Equal(t, topic, msg.Name)
+				case <-done:
+					want := [2]int{}
+					if allowed {
+						want = [2]int{1, 1}
+					}
+					assert.Equal(t, want, received)
+					return
+				case <-timer.C:
+					t.Fatal("broadcast did not finish")
+				}
+			}
+		}
+		check(nil, false)
+		check(outsider, false)
+		check(member, true)
+		_, err := app.DB().NewQuery(`UPDATE systems SET users = '[]'`).Execute()
+		require.NoError(t, err)
+		check(member, false)
+		t.Setenv("BESZEL_HUB_SHARE_ALL_SYSTEMS", "true")
+		check(outsider, true)
+		check(nil, false)
+	})
+}
+
+func newRealtimeTestManager() *SystemManager {
+	return &SystemManager{
+		systems:             store.New(map[string]*System{}),
+		activeSubscriptions: make(map[string]*subscriptionInfo),
+	}
+}
+
+func TestRealtimeFetchesDoNotOverlapPerSystem(t *testing.T) {
+	sm := newRealtimeTestManager()
+	sm.activeSubscriptions["one"] = &subscriptionInfo{subscription: "rt_metrics_one"}
+	sm.activeSubscriptions["two"] = &subscriptionInfo{subscription: "rt_metrics_two"}
+
+	first := sm.claimRealtimeFetches()
+	require.Len(t, first, 2)
+	assert.Empty(t, sm.claimRealtimeFetches())
+
+	sm.finishRealtimeFetch(first[0])
+	next := sm.claimRealtimeFetches()
+	require.Len(t, next, 1)
+	assert.Equal(t, first[0].systemID, next[0].systemID)
+
+	sm.finishRealtimeFetch(first[1])
+	sm.finishRealtimeFetch(next[0])
+}
+
+func TestFinishingOldRealtimeFetchDoesNotReleaseReplacement(t *testing.T) {
+	sm := newRealtimeTestManager()
+	oldInfo := &subscriptionInfo{subscription: "old"}
+	sm.activeSubscriptions["system"] = oldInfo
+
+	fetch := sm.claimRealtimeFetches()[0]
+	newInfo := &subscriptionInfo{subscription: "new", fetching: true}
+	sm.activeSubscriptions["system"] = newInfo
+
+	sm.finishRealtimeFetch(fetch)
+	assert.True(t, newInfo.fetching)
+}
+
+func TestRealtimeSubscriptionLifecycle(t *testing.T) {
+	sm := newRealtimeTestManager()
+	options := subscriptions.SubscriptionOptions{Query: map[string]string{"system": "system"}}
+
+	sm.addRealtimeSubscription("system", "rt_metrics")
+	sm.addRealtimeSubscription("system", "rt_metrics")
+
+	sm.realtimeMutex.Lock()
+	firstStop := sm.realtimeWorkerStop
+	assert.True(t, sm.realtimeWorkerRun)
+	assert.Equal(t, 2, sm.activeSubscriptions["system"].connectedClients)
+	sm.realtimeMutex.Unlock()
+
+	sm.removeRealtimeSubscription("rt_metrics", options)
+	sm.realtimeMutex.Lock()
+	assert.True(t, sm.realtimeWorkerRun)
+	assert.Equal(t, 1, sm.activeSubscriptions["system"].connectedClients)
+	sm.realtimeMutex.Unlock()
+
+	sm.removeRealtimeSubscription("rt_metrics", options)
+	sm.realtimeMutex.Lock()
+	assert.False(t, sm.realtimeWorkerRun)
+	assert.Empty(t, sm.activeSubscriptions)
+	sm.realtimeMutex.Unlock()
+	select {
+	case <-firstStop:
+	default:
+		t.Fatal("worker stop channel was not closed")
+	}
+
+	// A later subscription must get a new stop channel owned by its worker.
+	sm.addRealtimeSubscription("system", "rt_metrics")
+	sm.realtimeMutex.Lock()
+	secondStop := sm.realtimeWorkerStop
+	assert.NotEqual(t, firstStop, secondStop)
+	sm.realtimeMutex.Unlock()
+	sm.stopRealtimeWorker()
+}