--- src/sbin/newfs_hammer/newfs_hammer.c	2008/02/20 00:55:50	1.19
+++ src/sbin/newfs_hammer/newfs_hammer.c	2008/03/18 05:21:55	1.20
@@ -405,6 +405,8 @@ format_volume(struct volume_info *vol, i
 			&ondisk->vol0_blockmap[HAMMER_ZONE_SMALL_DATA_INDEX],
 			HAMMER_ZONE_SMALL_DATA);
 
+		format_undomap(ondisk);
+
 		ondisk->vol0_btree_root = format_root();
 		++ondisk->vol0_stat_inodes;	/* root inode */
 	} else {