diff --git a/utils/src/format.h b/utils/src/format.h
index d27748c0..bafaef80 100644
--- a/utils/src/format.h
+++ b/utils/src/format.h
@@ -24,6 +24,7 @@
 #define SCOUTFS_CHUNK_SHIFT 22
 #define SCOUTFS_CHUNK_SIZE (1 << SCOUTFS_CHUNK_SHIFT)
 #define SCOUTFS_CHUNK_BLOCK_SHIFT (SCOUTFS_CHUNK_SHIFT - SCOUTFS_BLOCK_SHIFT)
+#define SCOUTFS_CHUNK_BLOCK_MASK ((1 << SCOUTFS_CHUNK_BLOCK_SHIFT) - 1)
 #define SCOUTFS_BLOCKS_PER_CHUNK (1 << SCOUTFS_CHUNK_BLOCK_SHIFT)
 
 /*
@@ -93,6 +94,10 @@ struct scoutfs_ring_map_block {
 	__le64 blknos[0];
 } __packed;
 
+#define SCOUTFS_RING_MAP_BLOCKS \
+	((SCOUTFS_BLOCK_SIZE - sizeof(struct scoutfs_ring_map_block)) / \
+		sizeof(__le64))
+
 struct scoutfs_ring_entry {
 	u8 type;
 	__le16 len;
@@ -112,15 +117,11 @@ struct scoutfs_ring_block {
 } __packed;
 
 enum {
-	SCOUTFS_RING_REMOVE_MANIFEST = 0,
-	SCOUTFS_RING_ADD_MANIFEST,
+	SCOUTFS_RING_ADD_MANIFEST = 0,
+	SCOUTFS_RING_DEL_MANIFEST,
 	SCOUTFS_RING_BITMAP,
 };
 
-struct scoutfs_ring_remove_manifest {
-	__le64 blkno;
-} __packed;
-
 /*
  * Including both keys might make the manifest too large.  It might be
  * better to only include one key and infer a block's range from the
@@ -128,7 +129,7 @@ struct scoutfs_ring_remove_manifest {
  * isn't unused key space between blocks in a level.  We might search
  * blocks when we didn't need to.
  */
-struct scoutfs_ring_add_manifest {
+struct scoutfs_ring_manifest_entry {
 	__le64 blkno;
 	__le64 seq;
 	__u8 level;
@@ -136,6 +137,13 @@ struct scoutfs_ring_add_manifest {
 	struct scoutfs_key last;
 } __packed;
 
+struct scoutfs_ring_del_manifest {
+	__le64 blkno;
+} __packed;
+
+/* 2^22 * 10^13 > 2^64 */
+#define SCOUTFS_MAX_LEVEL 13
+
 struct scoutfs_ring_bitmap {
 	__le32 offset;
 	__le64 bits[2];
diff --git a/utils/src/mkfs.c b/utils/src/mkfs.c
index f42fbe04..396b3997 100644
--- a/utils/src/mkfs.c
+++ b/utils/src/mkfs.c
@@ -46,7 +46,7 @@ static int write_new_fs(char *path, int fd)
 	struct scoutfs_ring_map_block *map;
 	struct scoutfs_ring_block *ring;
 	struct scoutfs_ring_entry *ent;
-	struct scoutfs_ring_add_manifest *mani;
+	struct scoutfs_ring_manifest_entry *mani;
 	struct scoutfs_ring_bitmap *bm;
 	struct scoutfs_item_block *iblk;
 	struct scoutfs_item_header *ihdr;
diff --git a/utils/src/print.c b/utils/src/print.c
index 324db059..f00ef3e3 100644
--- a/utils/src/print.c
+++ b/utils/src/print.c
@@ -154,10 +154,10 @@ static int print_log_segments(int fd, __le64 *log_segs, u64 total_chunks)
 static char *ent_type_str(u8 type)
 {
 	switch (type) {
-		case SCOUTFS_RING_REMOVE_MANIFEST:
-			return "REMOVE_MANIFEST";
 		case SCOUTFS_RING_ADD_MANIFEST:
 			return "ADD_MANIFEST";
+		case SCOUTFS_RING_DEL_MANIFEST:
+			return "DEL_MANIFEST";
 		case SCOUTFS_RING_BITMAP:
 			return "BITMAP";
 		default:
@@ -167,8 +167,8 @@ static char *ent_type_str(u8 type)
 
 static void print_ring_entry(int fd, struct scoutfs_ring_entry *ent)
 {
-	struct scoutfs_ring_remove_manifest *rem;
-	struct scoutfs_ring_add_manifest *add;
+	struct scoutfs_ring_manifest_entry *ment;
+	struct scoutfs_ring_del_manifest *del;
 	struct scoutfs_ring_bitmap *bm;
 
 	printf("    entry:\n"
@@ -177,20 +177,20 @@ static void print_ring_entry(int fd, struct scoutfs_ring_entry *ent)
 	       ent->type, ent_type_str(ent->type), le16_to_cpu(ent->len));
 
 	switch(ent->type) {
-	case SCOUTFS_RING_REMOVE_MANIFEST:
-		rem = (void *)(ent + 1);
-		printf("            blkno: %llu\n",
-		       le64_to_cpu(rem->blkno));
-		break;
 	case SCOUTFS_RING_ADD_MANIFEST:
-		add = (void *)(ent + 1);
+		ment = (void *)(ent + 1);
 		printf("            blkno: %llu\n"
 		       "            seq: %llu\n"
 		       "            level: %u\n"
 		       "            first: "SKF"\n"
 		       "            last: "SKF"\n",
-		       le64_to_cpu(add->blkno), le64_to_cpu(add->seq),
-		       add->level, SKA(&add->first), SKA(&add->last));
+		       le64_to_cpu(ment->blkno), le64_to_cpu(ment->seq),
+		       ment->level, SKA(&ment->first), SKA(&ment->last));
+		break;
+	case SCOUTFS_RING_DEL_MANIFEST:
+		del = (void *)(ent + 1);
+		printf("            blkno: %llu\n",
+		       le64_to_cpu(del->blkno));
 		break;
 	case SCOUTFS_RING_BITMAP:
 		bm = (void *)(ent + 1);
@@ -205,21 +205,21 @@ static void print_ring_entry(int fd, struct scoutfs_ring_entry *ent)
 static void update_log_segs(struct scoutfs_ring_entry *ent,
 			       __le64 *log_segs)
 {
-	struct scoutfs_ring_remove_manifest *rem;
-	struct scoutfs_ring_add_manifest *add;
+	struct scoutfs_ring_manifest_entry *add;
+	struct scoutfs_ring_del_manifest *del;
 	u64 bit;
 
 	switch(ent->type) {
-	case SCOUTFS_RING_REMOVE_MANIFEST:
-		rem = (void *)(ent + 1);
-		bit = le64_to_cpu(rem->blkno) >> SCOUTFS_CHUNK_BLOCK_SHIFT;
-		clear_le_bit(log_segs, bit);
-		break;
 	case SCOUTFS_RING_ADD_MANIFEST:
 		add = (void *)(ent + 1);
 		bit = le64_to_cpu(add->blkno) >> SCOUTFS_CHUNK_BLOCK_SHIFT;
 		set_le_bit(log_segs, bit);
 		break;
+	case SCOUTFS_RING_DEL_MANIFEST:
+		del = (void *)(ent + 1);
+		bit = le64_to_cpu(del->blkno) >> SCOUTFS_CHUNK_BLOCK_SHIFT;
+		clear_le_bit(log_segs, bit);
+		break;
 	}
 }