Add zpool properties for allocation class space

The existing zpool properties accounting pool space (size, allocated,
fragmentation, expandsize, free, capacity) are based on the normal
metaslab class or are cumulative properties of all classes combined.

Add properties reporting the space accounting metrics for each metaslab
class individually.

Update ZTS to recognize the new properties and validate reported values.

Sponsored-by: Klara, Inc.
Signed-off-by: Ryan Moeller <ryan.moeller@klarasystems.com>

Author: Ryan Moeller

cmd/zpool/zpool_main.c

@@ -6954,7 +6954,19 @@ collect_vdev_prop(zpool_prop_t prop, uint64_t value, const char *str,
 
 	switch (prop) {
 	case ZPOOL_PROP_SIZE:
+	case ZPOOL_PROP_NORMAL_SIZE:
+	case ZPOOL_PROP_SPECIAL_SIZE:
+	case ZPOOL_PROP_DEDUP_SIZE:
+	case ZPOOL_PROP_LOG_SIZE:
+	case ZPOOL_PROP_ELOG_SIZE:
+	case ZPOOL_PROP_SELOG_SIZE:
 	case ZPOOL_PROP_EXPANDSZ:
+	case ZPOOL_PROP_NORMAL_EXPANDSZ:
+	case ZPOOL_PROP_SPECIAL_EXPANDSZ:
+	case ZPOOL_PROP_DEDUP_EXPANDSZ:
+	case ZPOOL_PROP_LOG_EXPANDSZ:
+	case ZPOOL_PROP_ELOG_EXPANDSZ:
+	case ZPOOL_PROP_SELOG_EXPANDSZ:
 	case ZPOOL_PROP_CHECKPOINT:
 	case ZPOOL_PROP_DEDUPRATIO:
 	case ZPOOL_PROP_DEDUPCACHED:
@@ -6965,6 +6977,12 @@ collect_vdev_prop(zpool_prop_t prop, uint64_t value, const char *str,
 			    format);
 		break;
 	case ZPOOL_PROP_FRAGMENTATION:
+	case ZPOOL_PROP_NORMAL_FRAGMENTATION:
+	case ZPOOL_PROP_SPECIAL_FRAGMENTATION:
+	case ZPOOL_PROP_DEDUP_FRAGMENTATION:
+	case ZPOOL_PROP_LOG_FRAGMENTATION:
+	case ZPOOL_PROP_ELOG_FRAGMENTATION:
+	case ZPOOL_PROP_SELOG_FRAGMENTATION:
 		if (value == ZFS_FRAG_INVALID) {
 			(void) strlcpy(propval, "-", sizeof (propval));
 		} else if (format == ZFS_NICENUM_RAW) {
@@ -6976,6 +6994,12 @@ collect_vdev_prop(zpool_prop_t prop, uint64_t value, const char *str,
 		}
 		break;
 	case ZPOOL_PROP_CAPACITY:
+	case ZPOOL_PROP_NORMAL_CAPACITY:
+	case ZPOOL_PROP_SPECIAL_CAPACITY:
+	case ZPOOL_PROP_DEDUP_CAPACITY:
+	case ZPOOL_PROP_LOG_CAPACITY:
+	case ZPOOL_PROP_ELOG_CAPACITY:
+	case ZPOOL_PROP_SELOG_CAPACITY:
 		/* capacity value is in parts-per-10,000 (aka permyriad) */
 		if (format == ZFS_NICENUM_RAW)
 			(void) snprintf(propval, sizeof (propval), "%llu",

include/sys/fs/zfs.h

@@ -273,9 +273,73 @@ typedef enum {
 	ZPOOL_PROP_DEDUP_TABLE_QUOTA,
 	ZPOOL_PROP_DEDUPCACHED,
 	ZPOOL_PROP_LAST_SCRUBBED_TXG,
+	ZPOOL_PROP_NORMAL_SIZE,
+	ZPOOL_PROP_NORMAL_CAPACITY,
+	ZPOOL_PROP_NORMAL_FREE,
+	ZPOOL_PROP_NORMAL_ALLOCATED,
+	ZPOOL_PROP_NORMAL_AVAILABLE,
+	ZPOOL_PROP_NORMAL_EXPANDSZ,
+	ZPOOL_PROP_NORMAL_FRAGMENTATION,
+	ZPOOL_PROP_SPECIAL_SIZE,
+	ZPOOL_PROP_SPECIAL_CAPACITY,
+	ZPOOL_PROP_SPECIAL_FREE,
+	ZPOOL_PROP_SPECIAL_ALLOCATED,
+	ZPOOL_PROP_SPECIAL_AVAILABLE,
+	ZPOOL_PROP_SPECIAL_EXPANDSZ,
+	ZPOOL_PROP_SPECIAL_FRAGMENTATION,
+	ZPOOL_PROP_DEDUP_SIZE,
+	ZPOOL_PROP_DEDUP_CAPACITY,
+	ZPOOL_PROP_DEDUP_FREE,
+	ZPOOL_PROP_DEDUP_ALLOCATED,
+	ZPOOL_PROP_DEDUP_AVAILABLE,
+	ZPOOL_PROP_DEDUP_EXPANDSZ,
+	ZPOOL_PROP_DEDUP_FRAGMENTATION,
+	ZPOOL_PROP_LOG_SIZE,
+	ZPOOL_PROP_LOG_CAPACITY,
+	ZPOOL_PROP_LOG_FREE,
+	ZPOOL_PROP_LOG_ALLOCATED,
+	ZPOOL_PROP_LOG_AVAILABLE,
+	ZPOOL_PROP_LOG_EXPANDSZ,
+	ZPOOL_PROP_LOG_FRAGMENTATION,
+	ZPOOL_PROP_ELOG_SIZE,
+	ZPOOL_PROP_ELOG_CAPACITY,
+	ZPOOL_PROP_ELOG_FREE,
+	ZPOOL_PROP_ELOG_ALLOCATED,
+	ZPOOL_PROP_ELOG_AVAILABLE,
+	ZPOOL_PROP_ELOG_EXPANDSZ,
+	ZPOOL_PROP_ELOG_FRAGMENTATION,
+	ZPOOL_PROP_SELOG_SIZE,
+	ZPOOL_PROP_SELOG_CAPACITY,
+	ZPOOL_PROP_SELOG_FREE,
+	ZPOOL_PROP_SELOG_ALLOCATED,
+	ZPOOL_PROP_SELOG_AVAILABLE,
+	ZPOOL_PROP_SELOG_EXPANDSZ,
+	ZPOOL_PROP_SELOG_FRAGMENTATION,
 	ZPOOL_NUM_PROPS
 } zpool_prop_t;
 
+/* Offsets for metaslab class properties. */
+typedef enum {
+	ZPOOL_MC_PROP_SIZE,
+	ZPOOL_MC_PROP_CAPACITY,
+	ZPOOL_MC_PROP_FREE,
+	ZPOOL_MC_PROP_ALLOCATED,
+	ZPOOL_MC_PROP_AVAILABLE,
+	ZPOOL_MC_PROP_EXPANDSZ,
+	ZPOOL_MC_PROP_FRAGMENTATION,
+	ZPOOL_NUM_MC_PROPS
+} zpool_mc_prop_t;
+
+/* Offsets for metaslab class property groups. */
+typedef enum {
+	ZPOOL_MC_PROPS_NORMAL = ZPOOL_PROP_NORMAL_SIZE,
+	ZPOOL_MC_PROPS_SPECIAL = ZPOOL_PROP_SPECIAL_SIZE,
+	ZPOOL_MC_PROPS_DEDUP = ZPOOL_PROP_DEDUP_SIZE,
+	ZPOOL_MC_PROPS_LOG = ZPOOL_PROP_LOG_SIZE,
+	ZPOOL_MC_PROPS_ELOG = ZPOOL_PROP_ELOG_SIZE,
+	ZPOOL_MC_PROPS_SELOG = ZPOOL_PROP_SELOG_SIZE,
+} zpool_mc_props_t;
+
 /* Small enough to not hog a whole line of printout in zpool(8). */
 #define	ZPROP_MAX_COMMENT	32
 #define	ZPROP_BOOLEAN_NA	2

lib/libzfs/libzfs_pool.c

@@ -370,8 +370,32 @@ zpool_get_prop(zpool_handle_t *zhp, zpool_prop_t prop, char *buf,
 			zfs_fallthrough;
 
 		case ZPOOL_PROP_SIZE:
+		case ZPOOL_PROP_NORMAL_SIZE:
+		case ZPOOL_PROP_SPECIAL_SIZE:
+		case ZPOOL_PROP_DEDUP_SIZE:
+		case ZPOOL_PROP_LOG_SIZE:
+		case ZPOOL_PROP_ELOG_SIZE:
+		case ZPOOL_PROP_SELOG_SIZE:
 		case ZPOOL_PROP_ALLOCATED:
+		case ZPOOL_PROP_NORMAL_ALLOCATED:
+		case ZPOOL_PROP_SPECIAL_ALLOCATED:
+		case ZPOOL_PROP_DEDUP_ALLOCATED:
+		case ZPOOL_PROP_LOG_ALLOCATED:
+		case ZPOOL_PROP_ELOG_ALLOCATED:
+		case ZPOOL_PROP_SELOG_ALLOCATED:
+		case ZPOOL_PROP_NORMAL_AVAILABLE:
+		case ZPOOL_PROP_SPECIAL_AVAILABLE:
+		case ZPOOL_PROP_DEDUP_AVAILABLE:
+		case ZPOOL_PROP_LOG_AVAILABLE:
+		case ZPOOL_PROP_ELOG_AVAILABLE:
+		case ZPOOL_PROP_SELOG_AVAILABLE:
 		case ZPOOL_PROP_FREE:
+		case ZPOOL_PROP_NORMAL_FREE:
+		case ZPOOL_PROP_SPECIAL_FREE:
+		case ZPOOL_PROP_DEDUP_FREE:
+		case ZPOOL_PROP_LOG_FREE:
+		case ZPOOL_PROP_ELOG_FREE:
+		case ZPOOL_PROP_SELOG_FREE:
 		case ZPOOL_PROP_FREEING:
 		case ZPOOL_PROP_LEAKED:
 		case ZPOOL_PROP_ASHIFT:
@@ -389,6 +413,12 @@ zpool_get_prop(zpool_handle_t *zhp, zpool_prop_t prop, char *buf,
 			break;
 
 		case ZPOOL_PROP_EXPANDSZ:
+		case ZPOOL_PROP_NORMAL_EXPANDSZ:
+		case ZPOOL_PROP_SPECIAL_EXPANDSZ:
+		case ZPOOL_PROP_DEDUP_EXPANDSZ:
+		case ZPOOL_PROP_LOG_EXPANDSZ:
+		case ZPOOL_PROP_ELOG_EXPANDSZ:
+		case ZPOOL_PROP_SELOG_EXPANDSZ:
 		case ZPOOL_PROP_CHECKPOINT:
 			if (intval == 0) {
 				(void) strlcpy(buf, "-", len);
@@ -401,6 +431,12 @@ zpool_get_prop(zpool_handle_t *zhp, zpool_prop_t prop, char *buf,
 			break;
 
 		case ZPOOL_PROP_CAPACITY:
+		case ZPOOL_PROP_NORMAL_CAPACITY:
+		case ZPOOL_PROP_SPECIAL_CAPACITY:
+		case ZPOOL_PROP_DEDUP_CAPACITY:
+		case ZPOOL_PROP_LOG_CAPACITY:
+		case ZPOOL_PROP_ELOG_CAPACITY:
+		case ZPOOL_PROP_SELOG_CAPACITY:
 			if (literal) {
 				(void) snprintf(buf, len, "%llu",
 				    (u_longlong_t)intval);
@@ -411,7 +447,13 @@ zpool_get_prop(zpool_handle_t *zhp, zpool_prop_t prop, char *buf,
 			break;
 
 		case ZPOOL_PROP_FRAGMENTATION:
-			if (intval == UINT64_MAX) {
+		case ZPOOL_PROP_NORMAL_FRAGMENTATION:
+		case ZPOOL_PROP_SPECIAL_FRAGMENTATION:
+		case ZPOOL_PROP_DEDUP_FRAGMENTATION:
+		case ZPOOL_PROP_LOG_FRAGMENTATION:
+		case ZPOOL_PROP_ELOG_FRAGMENTATION:
+		case ZPOOL_PROP_SELOG_FRAGMENTATION:
+			if (intval == ZFS_FRAG_INVALID) {
 				(void) strlcpy(buf, "-", len);
 			} else if (literal) {
 				(void) snprintf(buf, len, "%llu",

man/man7/zpoolprops.7

@@ -27,9 +27,9 @@
 .\" Copyright 2017 Nexenta Systems, Inc.
 .\" Copyright (c) 2017 Open-E, Inc. All Rights Reserved.
 .\" Copyright (c) 2021, Colm Buckley <colm@tuatha.org>
-.\" Copyright (c) 2023, Klara Inc.
+.\" Copyright (c) 2023, 2026, Klara Inc.
 .\"
-.Dd December 4, 2024
+.Dd January 31, 2026
 .Dt ZPOOLPROPS 7
 .Os
 .
@@ -49,7 +49,7 @@ For more information about user properties, see the
 section.
 .Pp
 The following are read-only properties:
-.Bl -tag -width "unsupported@guid"
+.Bl -tag -width "last_scrubbed_txg"
 .It Sy allocated
 Amount of storage used within the pool.
 See
@@ -186,6 +186,96 @@ For non-full pools of a reasonable size, these effects should be invisible.
 For small pools, or pools that are close to being completely full, these
 discrepancies may become more noticeable.
 .Pp
+The following properties are read-only metrics for allocation classes:
+.Bl -ohang
+.It Xo Sy dedup_allocated , dedup_available , dedup_capacity ,
+.Sy dedup_expandsize , dedup_fragmentation , dedup_free
+.Xc
+.Bd -ragged -offset Ds -compact
+Space usage properties of the pool's
+.Sy dedup
+metaslab allocator class.
+.Ed
+.It Xo Sy embedded_log_allocated , embedded_log_available ,
+.Sy embedded_log_capacity , embedded_log_expandsize ,
+.Sy embedded_log_fragmentation , embedded_log_free
+.Xc
+.Bd -ragged -offset Ds -compact
+Space usage properties of the pool's
+.Sy embedded_log
+metaslab allocator class.
+.Ed
+.It Xo Sy log_allocated , log_available , log_capacity , log_expandsize ,
+.Sy log_fragmentation , log_free
+.Xc
+.Bd -ragged -offset Ds -compact
+Space usage properties of the pool's
+.Sy log
+metaslab allocator class.
+.Ed
+.It Xo Sy normal_allocated , normal_available , normal_capacity ,
+.Sy normal_expandsize , normal_fragmentation , normal_free
+.Xc
+.Bd -ragged -offset Ds -compact
+Space usage properties of the pool's
+.Sy normal
+metaslab allocator class.
+.Ed
+.It Xo Sy special_allocated , special_available , special_capacity ,
+.Sy special_expandsize , special_fragmentation , special_free
+.Xc
+.Bd -ragged -offset Ds -compact
+Space usage properties of the pool's
+.Sy special
+metaslab allocator class.
+.Ed
+.It Xo Sy special_embedded_log_allocated , special_embedded_log_available ,
+.Sy special_embedded_log_capacity , special_embedded_log_expandsize ,
+.Sy special_embedded_log_fragmentation , special_embedded_log_free
+.Xc
+.Bd -ragged -offset Ds -compact
+Space usage properties of the pool's
+.Sy special_embedded_log
+metaslab allocator class.
+.Ed
+.El
+.Pp
+Each allocation class is described by these values:
+.Bl -tag -width "fragmentation"
+.It Sy allocated
+Amount of storage used within the allocation class.
+.It Sy available
+Estimate of free space available in the allocation class, adjusted for raidz
+parity overhead.
+The adjustment assumes a fixed 128KiB record size to compute a data-to-parity
+ratio.
+.Sy available
+is a heuristic for allocation and should not be interpreted as an exact measure
+of usable space.
+Actual usable space depends on a variety of factors such as dataset record size
+and compression.
+.It Sy capacity
+Percentage of allocation class space used.
+.It Sy expandsize
+Amount of uninitialized space within the allocation class that can be used to
+increase the capacity of the allocator.
+See the pool-wide
+.Sy expandsize
+property.
+.It Sy fragmentation
+The amount of fragmentation in the allocation class.
+See the pool-wide
+.Sy fragmentation
+property.
+.It Sy free
+The amount of free space available in the allocation class.
+This value is not adjusted for factors such as dataset record size, compression,
+or raidz parity overhead.
+See the pool-wide
+.Sy free
+property.
+.El
+.Pp
 The following property can be set at creation time and import time:
 .Bl -tag -width Ds
 .It Sy altroot

module/zcommon/zpool_prop.c

@@ -50,6 +50,31 @@ zpool_prop_get_table(void)
 	return (zpool_prop_table);
 }
 
+#define zpool_mc_props_init(uclass, lclass, sfeatures) ({ \
+	zpool_mc_props_t mcp = ZPOOL_MC_PROPS_##uclass; \
+	zprop_register_number(mcp + ZPOOL_MC_PROP_SIZE, \
+	    #lclass "_size", 0, PROP_READONLY, ZFS_TYPE_POOL, "<size>", \
+	    #uclass "_SIZE", B_FALSE, sfeatures); \
+	zprop_register_number(mcp + ZPOOL_MC_PROP_CAPACITY, \
+	    #lclass "_capacity", 0, PROP_READONLY, ZFS_TYPE_POOL, "<percent>", \
+	    #uclass "_CAP", B_FALSE, sfeatures); \
+	zprop_register_number(mcp + ZPOOL_MC_PROP_FREE, \
+	    #lclass "_free", 0, PROP_READONLY, ZFS_TYPE_POOL, "<size>", \
+	    #uclass "_FREE", B_FALSE, sfeatures); \
+	zprop_register_number(mcp + ZPOOL_MC_PROP_ALLOCATED, \
+	    #lclass "_allocated", 0, PROP_READONLY, ZFS_TYPE_POOL, "<size>", \
+	    #uclass "_ALLOC", B_FALSE, sfeatures); \
+	zprop_register_number(mcp + ZPOOL_MC_PROP_AVAILABLE, \
+	    #lclass "_available", 0, PROP_READONLY, ZFS_TYPE_POOL, "<size>", \
+	    #uclass "_AVAIL", B_FALSE, sfeatures); \
+	zprop_register_number(mcp + ZPOOL_MC_PROP_EXPANDSZ, \
+	    #lclass "_expandsize", 0, PROP_READONLY, ZFS_TYPE_POOL, "<size>", \
+	    #uclass "_EXPANDSZ", B_FALSE, sfeatures); \
+	zprop_register_number(mcp + ZPOOL_MC_PROP_FRAGMENTATION, \
+	    #lclass "_fragmentation", 0, PROP_READONLY, ZFS_TYPE_POOL, \
+	    "<percent>", #uclass "_FRAG", B_FALSE, sfeatures); \
+})
+
 void
 zpool_prop_init(void)
 {
@@ -133,6 +158,13 @@ zpool_prop_init(void)
 	    "last_scrubbed_txg", 0, PROP_READONLY, ZFS_TYPE_POOL, "<txg>",
 	    "LAST_SCRUBBED_TXG", B_FALSE, sfeatures);
 
+	zpool_mc_props_init(NORMAL, normal, sfeatures);
+	zpool_mc_props_init(SPECIAL, special, sfeatures);
+	zpool_mc_props_init(DEDUP, dedup, sfeatures);
+	zpool_mc_props_init(LOG, log, sfeatures);
+	zpool_mc_props_init(ELOG, embedded_log, sfeatures);
+	zpool_mc_props_init(SELOG, special_embedded_log, sfeatures);
+
 	/* default number properties */
 	zprop_register_number(ZPOOL_PROP_VERSION, "version", SPA_VERSION,
 	    PROP_DEFAULT, ZFS_TYPE_POOL, "<version>", "VERSION", B_FALSE,

module/zfs/metaslab.c

@@ -805,6 +805,10 @@ metaslab_class_fragmentation(metaslab_class_t *mc)
 {
 	vdev_t *rvd = mc->mc_spa->spa_root_vdev;
 	uint64_t fragmentation = 0;
+	uint64_t space = metaslab_class_get_space(mc);
+
+	if (space == 0)
+		return (ZFS_FRAG_INVALID);
 
 	spa_config_enter(mc->mc_spa, SCL_VDEV, FTAG, RW_READER);
 
@@ -837,7 +841,7 @@ metaslab_class_fragmentation(metaslab_class_t *mc)
 		fragmentation += mg->mg_fragmentation *
 		    metaslab_group_get_space(mg);
 	}
-	fragmentation /= metaslab_class_get_space(mc);
+	fragmentation /= space;
 
 	ASSERT3U(fragmentation, <=, 100);
 	spa_config_exit(mc->mc_spa, SCL_VDEV, FTAG);