diff --git a/cmd/zdb/zdb.c b/cmd/zdb/zdb.c
index d4d32b999608..2ce719d21dd2 100644
--- a/cmd/zdb/zdb.c
+++ b/cmd/zdb/zdb.c
@@ -1997,6 +1997,8 @@ typedef struct zdb_blkstats {
 	uint64_t zb_lsize;
 	uint64_t zb_psize;
 	uint64_t zb_count;
+	uint64_t zb_gangs;
+	uint64_t zb_ditto_samevdev;
 	uint64_t zb_psize_histogram[PSIZE_HISTO_SIZE];
 } zdb_blkstats_t;
 
@@ -2044,6 +2046,7 @@ zdb_count_block(zdb_cb_t *zcb, zilog_t *zilog, const blkptr_t *bp,
 	for (int i = 0; i < 4; i++) {
 		int l = (i < 2) ? BP_GET_LEVEL(bp) : ZB_TOTAL;
 		int t = (i & 1) ? type : ZDB_OT_TOTAL;
+		int equal;
 		zdb_blkstats_t *zb = &zcb->zcb_type[l][t];
 
 		zb->zb_asize += BP_GET_ASIZE(bp);
@@ -2051,6 +2054,27 @@ zdb_count_block(zdb_cb_t *zcb, zilog_t *zilog, const blkptr_t *bp,
 		zb->zb_psize += BP_GET_PSIZE(bp);
 		zb->zb_count++;
 		zb->zb_psize_histogram[BP_GET_PSIZE(bp) >> SPA_MINBLOCKSHIFT]++;
+
+		zb->zb_gangs += BP_COUNT_GANG(bp);
+
+		switch (BP_GET_NDVAS(bp)) {
+		case 2:
+			if (DVA_GET_VDEV(&bp->blk_dva[0]) ==
+			    DVA_GET_VDEV(&bp->blk_dva[1]))
+				zb->zb_ditto_samevdev++;
+			break;
+		case 3:
+			equal = (DVA_GET_VDEV(&bp->blk_dva[0]) ==
+			    DVA_GET_VDEV(&bp->blk_dva[1])) +
+			    (DVA_GET_VDEV(&bp->blk_dva[0]) ==
+			    DVA_GET_VDEV(&bp->blk_dva[2])) +
+			    (DVA_GET_VDEV(&bp->blk_dva[1]) ==
+			    DVA_GET_VDEV(&bp->blk_dva[2]));
+			if (equal != 0)
+				zb->zb_ditto_samevdev++;
+			break;
+		}
+
 	}
 
 	if (dump_opt['L'])
@@ -2439,6 +2463,8 @@ dump_block_stats(spa_t *spa)
 	(void) printf("\n");
 	(void) printf("\tbp count:      %10llu\n",
 	    (u_longlong_t)tzb->zb_count);
+	(void) printf("\tganged count:  %10llu\n",
+	    (longlong_t)tzb->zb_gangs);
 	(void) printf("\tbp logical:    %10llu      avg: %6llu\n",
 	    (u_longlong_t)tzb->zb_lsize,
 	    (u_longlong_t)(tzb->zb_lsize / tzb->zb_count));
@@ -2460,6 +2486,11 @@ dump_block_stats(spa_t *spa)
 	(void) printf("\tSPA allocated: %10llu     used: %5.2f%%\n",
 	    (u_longlong_t)norm_alloc, 100.0 * norm_alloc / norm_space);
 
+	if (tzb->zb_ditto_samevdev != 0) {
+		(void) printf("\tDittoed blocks on same vdev: %llu\n",
+		    (longlong_t)tzb->zb_ditto_samevdev);
+	}
+
 	if (dump_opt['b'] >= 2) {
 		int l, t, level;
 		(void) printf("\nBlocks\tLSIZE\tPSIZE\tASIZE"
@@ -2467,7 +2498,7 @@ dump_block_stats(spa_t *spa)
 
 		for (t = 0; t <= ZDB_OT_TOTAL; t++) {
 			char csize[32], lsize[32], psize[32], asize[32];
-			char avg[32];
+			char avg[32], gang[32];
 			char *typename;
 
 			if (t < DMU_OT_NUMTYPES)
@@ -2508,6 +2539,7 @@ dump_block_stats(spa_t *spa)
 				zdb_nicenum(zb->zb_psize, psize);
 				zdb_nicenum(zb->zb_asize, asize);
 				zdb_nicenum(zb->zb_asize / zb->zb_count, avg);
+				zdb_nicenum(zb->zb_gangs, gang);
 
 				(void) printf("%6s\t%5s\t%5s\t%5s\t%5s"
 				    "\t%5.2f\t%6.2f\t",
@@ -2521,6 +2553,11 @@ dump_block_stats(spa_t *spa)
 					(void) printf("    L%d %s\n",
 					    level, typename);
 
+				if (dump_opt['b'] >= 3 && zb->zb_gangs > 0) {
+					(void) printf("\t number of ganged "
+					    "blocks: %s\n", gang);
+				}
+
 				if (dump_opt['b'] >= 4) {
 					(void) printf("psize "
 					    "(in 512-byte sectors): "
diff --git a/uts/common/fs/zfs/sys/zap.h b/uts/common/fs/zfs/sys/zap.h
index 092669c8b3ab..1e975e99e0dd 100644
--- a/uts/common/fs/zfs/sys/zap.h
+++ b/uts/common/fs/zfs/sys/zap.h
@@ -20,7 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012 by Delphix. All rights reserved.
+ * Copyright (c) 2013 by Delphix. All rights reserved.
  */
 
 #ifndef	_SYS_ZAP_H
@@ -367,11 +367,6 @@ void zap_cursor_advance(zap_cursor_t *zc);
  */
 uint64_t zap_cursor_serialize(zap_cursor_t *zc);
 
-/*
- * Advance the cursor to the attribute having the given key.
- */
-int zap_cursor_move_to_key(zap_cursor_t *zc, const char *name, matchtype_t mt);
-
 /*
  * Initialize a zap cursor pointing to the position recorded by
  * zap_cursor_serialize (in the "serialized" argument).  You can also
diff --git a/uts/common/fs/zfs/sys/zap_impl.h b/uts/common/fs/zfs/sys/zap_impl.h
index 1dc322e02f6f..466aab02bacb 100644
--- a/uts/common/fs/zfs/sys/zap_impl.h
+++ b/uts/common/fs/zfs/sys/zap_impl.h
@@ -20,6 +20,7 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013 by Delphix. All rights reserved.
  */
 
 #ifndef	_SYS_ZAP_IMPL_H
@@ -219,7 +220,6 @@ int fzap_add_cd(zap_name_t *zn,
     uint64_t integer_size, uint64_t num_integers,
     const void *val, uint32_t cd, dmu_tx_t *tx);
 void fzap_upgrade(zap_t *zap, dmu_tx_t *tx, zap_flags_t flags);
-int fzap_cursor_move_to_key(zap_cursor_t *zc, zap_name_t *zn);
 
 #ifdef	__cplusplus
 }
diff --git a/uts/common/fs/zfs/zap.c b/uts/common/fs/zfs/zap.c
index 0e637d56c939..2f4ccfb6ea74 100644
--- a/uts/common/fs/zfs/zap.c
+++ b/uts/common/fs/zfs/zap.c
@@ -1242,31 +1242,6 @@ zap_stats_ptrtbl(zap_t *zap, uint64_t *tbl, int len, zap_stats_t *zs)
 	}
 }
 
-int
-fzap_cursor_move_to_key(zap_cursor_t *zc, zap_name_t *zn)
-{
-	int err;
-	zap_leaf_t *l;
-	zap_entry_handle_t zeh;
-
-	if (zn->zn_key_orig_numints * zn->zn_key_intlen > ZAP_MAXNAMELEN)
-		return (SET_ERROR(ENAMETOOLONG));
-
-	err = zap_deref_leaf(zc->zc_zap, zn->zn_hash, NULL, RW_READER, &l);
-	if (err != 0)
-		return (err);
-
-	err = zap_leaf_lookup(l, zn, &zeh);
-	if (err != 0)
-		return (err);
-
-	zc->zc_leaf = l;
-	zc->zc_hash = zeh.zeh_hash;
-	zc->zc_cd = zeh.zeh_cd;
-
-	return (err);
-}
-
 void
 fzap_get_stats(zap_t *zap, zap_stats_t *zs)
 {
diff --git a/uts/common/fs/zfs/zap_micro.c b/uts/common/fs/zfs/zap_micro.c
index e79038017f53..e2fc0118c6ce 100644
--- a/uts/common/fs/zfs/zap_micro.c
+++ b/uts/common/fs/zfs/zap_micro.c
@@ -1315,46 +1315,6 @@ zap_cursor_advance(zap_cursor_t *zc)
 	zc->zc_cd++;
 }
 
-int
-zap_cursor_move_to_key(zap_cursor_t *zc, const char *name, matchtype_t mt)
-{
-	int err = 0;
-	mzap_ent_t *mze;
-	zap_name_t *zn;
-
-	if (zc->zc_zap == NULL) {
-		err = zap_lockdir(zc->zc_objset, zc->zc_zapobj, NULL,
-		    RW_READER, TRUE, FALSE, &zc->zc_zap);
-		if (err)
-			return (err);
-	} else {
-		rw_enter(&zc->zc_zap->zap_rwlock, RW_READER);
-	}
-
-	zn = zap_name_alloc(zc->zc_zap, name, mt);
-	if (zn == NULL) {
-		rw_exit(&zc->zc_zap->zap_rwlock);
-		return (SET_ERROR(ENOTSUP));
-	}
-
-	if (!zc->zc_zap->zap_ismicro) {
-		err = fzap_cursor_move_to_key(zc, zn);
-	} else {
-		mze = mze_find(zn);
-		if (mze == NULL) {
-			err = SET_ERROR(ENOENT);
-			goto out;
-		}
-		zc->zc_hash = mze->mze_hash;
-		zc->zc_cd = mze->mze_cd;
-	}
-
-out:
-	zap_name_free(zn);
-	rw_exit(&zc->zc_zap->zap_rwlock);
-	return (err);
-}
-
 int
 zap_get_stats(objset_t *os, uint64_t zapobj, zap_stats_t *zs)
 {