On Wed, Mar 2, 2016 at 3:47 AM, Stuart Gittings <gittings.s@xxxxxxxxx> wrote: > Hi - I have some corruption on a 12 drive Raid 6 volume. Here's the > basics - if someone could help with restore it would save me a ton of > time (and some data loss - I have critical data backed up, but not > all). > > stuart@debian:~$ uname -a > Linux debian 4.3.0-0.bpo.1-amd64 #1 SMP Debian 4.3.3-7~bpo8+1 > (2016-01-19) x86_64 GNU/Linux > > stuart@debian:~$ sudo btrfs --version > btrfs-progs v4.4 > > sudo btrfs fi sh > Label: none uuid: 7f994e11-e146-4dee-80f0-c16ac3073e91 > Total devices 12 FS bytes used 14.25TiB > devid 1 size 2.73TiB used 167.14GiB path /dev/sdc > devid 2 size 5.46TiB used 1.75TiB path /dev/sdd > devid 3 size 5.46TiB used 1.75TiB path /dev/sde > devid 4 size 2.73TiB used 167.14GiB path /dev/sdn > devid 5 size 5.46TiB used 1.75TiB path /dev/sdf > devid 6 size 2.73TiB used 1.75TiB path /dev/sdm > devid 9 size 2.73TiB used 1.75TiB path /dev/sdj > devid 10 size 2.73TiB used 1.75TiB path /dev/sdi > devid 11 size 2.73TiB used 1.75TiB path /dev/sdg > devid 13 size 2.73TiB used 1.75TiB path /dev/sdl > devid 14 size 2.73TiB used 1.75TiB path /dev/sdk > devid 15 size 2.73TiB used 1.75TiB path /dev/sdh > > sudo mount -t btrfs -oro,recover /dev/sdc /data > mount: wrong fs type, bad option, bad superblock on /dev/sdc, > missing codepage or helper program, or other error > > In some cases useful info is found in syslog - try > dmesg | tail or so. > > dmesg: > > [ 5642.118303] BTRFS info (device sdc): enabling auto recovery > [ 5642.118313] BTRFS info (device sdc): disk space caching is enabled > [ 5642.118316] BTRFS: has skinny extents > [ 5642.130145] btree_readpage_end_io_hook: 39 callbacks suppressed > [ 5642.130148] BTRFS (device sdc): bad tree block start > 13629298965300190098 47255853072384 > [ 5642.130759] BTRFS (device sdc): bad tree block start > 10584834564968318131 47255853105152 > [ 5642.131289] BTRFS (device sdc): bad tree block start > 2775635947161390306 47255853121536 > [ 5644.730012] BTRFS: bdev /dev/sdc errs: wr 1664846, rd 210656, flush > 18054, corrupt 0, gen 0 > [ 5644.801291] BTRFS (device sdc): bad tree block start > 8578409561856120450 47254279438336 > [ 5644.801304] BTRFS (device sdc): bad tree block start > 18087369170870825197 47254279454720 > [ 5644.831199] BTRFS (device sdc): bad tree block start > 9721403008164124267 47254277718016 > [ 5644.842763] BTRFS (device sdc): bad tree block start > 18087369170870825197 47254279454720 > [ 5644.891992] BTRFS (device sdc): bad tree block start > 17582844917171188859 47254194176000 > [ 5644.951366] BTRFS (device sdc): bad tree block start > 3962496226683925584 47254278586368 > [ 5645.097168] BTRFS (device sdc): bad tree block start > 17049293152820168762 47255619846144 > [ 5646.159819] BTRFS: Failed to read block groups: -5 > [ 5646.215905] BTRFS: open_ctree failed > stuart@debian:~$ > > Finally: > sudo btrfs restore /dev/sdc /backup > checksum verify failed on 47255853072384 found 70F58CCA wanted AE18D5BC > checksum verify failed on 47255853072384 found 70F58CCA wanted AE18D5BC > checksum verify failed on 47255853072384 found 805B1FF7 wanted B76A652F > checksum verify failed on 47255853072384 found 70F58CCA wanted AE18D5BC > bytenr mismatch, want=47255853072384, have=13629298965300190098 > Couldn't read chunk tree > Could not open root, trying backup super > warning, device 3 is missing > warning, device 2 is missing > warning, device 5 is missing > warning, device 4 is missing > bytenr mismatch, want=47255851761664, have=47255851958272 > Couldn't read chunk root > Could not open root, trying backup super > warning, device 3 is missing > warning, device 2 is missing > warning, device 5 is missing > warning, device 4 is missing > bytenr mismatch, want=47255851761664, have=47255851958272 > Couldn't read chunk root > Could not open root, trying backup super > Well there appear to be too many devices missing, I count four. What does 'btrfs fi show' look like? If there are missing devices, try 'btrfs dev scan' and then 'btrfs fi show' again and see if it changes. I don't think much can be done if there really are four missing devices. -- Chris Murphy -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
