diff --git a/weed/topology/disk.go b/weed/topology/disk.go
index 1a952b481..7bffdfcf1 100644
--- a/weed/topology/disk.go
+++ b/weed/topology/disk.go
@@ -230,6 +230,14 @@ func (d *Disk) doAddOrUpdateVolume(v storage.VolumeInfo, fromReport bool) (isNew
 		d.UpAdjustDiskUsageDelta(types.ToDiskType(v.DiskType), deltaDiskUsage)
 		isNew = true
 	} else {
+		if !fromReport && v.DiskId == 0 && oldV.DiskId != 0 {
+			// A provisional (grow-time) record carries no disk id -- the
+			// master cannot know which directory the server chose. Keep the
+			// one the server's report already named, before the digest below
+			// is computed, or the stored record would drift from what the
+			// server keeps reporting.
+			v.DiskId = oldV.DiskId
+		}
 		if oldV.IsRemote() != v.IsRemote() {
 			if v.IsRemote() {
 				deltaDiskUsage.remoteVolumeCount = 1
diff --git a/weed/topology/disk_provisional_disk_id_test.go b/weed/topology/disk_provisional_disk_id_test.go
new file mode 100644
index 000000000..b06fd09fd
--- /dev/null
+++ b/weed/topology/disk_provisional_disk_id_test.go
@@ -0,0 +1,33 @@
+package topology
+
+import (
+	"testing"
+
+	"github.com/seaweedfs/seaweedfs/weed/storage"
+	"github.com/seaweedfs/seaweedfs/weed/storage/types"
+)
+
+// A provisional (grow-time) registration carries no disk id; when it lands
+// after the server's own report -- the server pushes its report during the
+// AllocateVolume RPC, so either order happens -- it must not erase the disk id
+// the report recorded.
+func TestProvisionalUpdateKeepsReportedDiskId(t *testing.T) {
+	disk := NewDisk(types.HardDriveType.String())
+
+	disk.AddOrUpdateVolume(storage.VolumeInfo{Id: 1, DiskId: 2})
+	disk.AddProvisionalVolume(storage.VolumeInfo{Id: 1})
+
+	v, err := disk.GetVolumesById(1)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if v.DiskId != 2 {
+		t.Fatalf("DiskId = %d, want 2 (provisional update clobbered the reported value)", v.DiskId)
+	}
+
+	// A later server report naming a different disk still wins.
+	disk.AddOrUpdateVolume(storage.VolumeInfo{Id: 1, DiskId: 1})
+	if v, _ = disk.GetVolumesById(1); v.DiskId != 1 {
+		t.Fatalf("DiskId = %d, want 1 (a real report must override)", v.DiskId)
+	}
+}