I''ve read the entire thread "Oops while rebalancing, now unmountable." and it ended without any information about repairing the fs. (the web page wouldn''t let me post a reply to that thread tho.) Has there been any info? The fs was working fine until I rebooted. thanks for any info! --jeff root@aurora:~/btrfs-progs-unstable# uname -a Linux aurora 2.6.38-8-generic-pae #42-Ubuntu SMP Mon Apr 11 05:17:09 UTC 2011 i686 i686 i386 GNU/Linux root@aurora:~/btrfs-progs-unstable# mount -t btrfs -r -o defaults,relatime,compress,space_cache /dev/dm-0 /mnt mount: wrong fs type, bad option, bad superblock on /dev/mapper/put--vg-put, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so root@aurora:~/btrfs-progs-unstable# dmesg |tail -6 [33472.371273] device label putBtrfs devid 1 transid 519691 /dev/mapper/put--vg-put [33472.373079] btrfs: use zlib compression [33472.373083] btrfs: enabling disk space caching [33478.399721] btrfs: dm-0 checksum verify failed on 12883853500416 wanted 9E7E27F5 found CC775767 level 0 [33478.399733] Failed to read block groups: -5 [33478.420497] btrfs: open_ctree failed root@aurora:~/btrfs-progs-unstable# ./btrfsck -s 0 /dev/dm-0 using SB copy 0, bytenr 65536 checksum verify failed on 12883853500416 wanted CC775767 found FFFFFFF5 Segmentation fault root@aurora:~/btrfs-progs-unstable# ./btrfsck -s 1 /dev/dm-0 using SB copy 1, bytenr 67108864 checksum verify failed on 12883853500416 wanted CC775767 found FFFFFFF5 Segmentation fault root@aurora:~/btrfs-progs-unstable# ./btrfsck -s 2 /dev/dm-0 using SB copy 2, bytenr 274877906944 checksum verify failed on 12883853500416 wanted CC775767 found FFFFFFF5 Segmentation fault root@aurora:~/btrfs-progs-unstable# ./btrfsck -s 3 /dev/dm-0 using SB copy 3, bytenr 1125899906842624 No valid Btrfs found on /dev/dm-0 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html