On Fri, Jan 22, 2016 at 04:11:53PM +0100, Radek Sprta wrote: > Hello everybody, > > after a recent power outage attempting to mount a my btrfs partition > fails with the following error: > > mount: wrong fs type, bad option, bad superblock on /dev/sda8, > missing codepage or helper program, or other error > > This is what dmesg shows: > [ 1035.236081] BTRFS (device sda8): parent transid verify failed on > 410124288 wanted 85753 found 85755 > [ 1035.240756] BTRFS (device sda8): parent transid verify failed on > 410124288 wanted 85753 found 85755 > [ 1035.240780] BTRFS: failed to read tree root on sda8 > [ 1035.252025] BTRFS: open_ctree failed Try mounting with -orecovery. That's the main approach for dealing with transid failures. > Below is the result of btrfs check: > Checking filesystem on /dev/sda8 > UUID: b0486700-ff9f-4979-8735-257ff1428a0d > checking extents > checking free space cache > checking fs roots > checking csums > checking root refs > found 311702978854 bytes used err is 0 > total csum bytes: 271057636 > total tree bytes: 1859862528 > total fs tree bytes: 1473953792 > total extent tree bytes: 72876032 > btree space waste bytes: 377740163 > file data blocks allocated: 11278336921600 > referenced 975937630208 > btrfs-progs v4.0 That looks reasonably promising -- nothing seriously damaged that btrfs check could find, at least. > I tried googling the "open_ctree failed" error, but couldn't find any > definite answers. Here's some additional info: "open_ctree failed" is a really generic error message, unfortunately. Almost every case that leads to a failure to mount will output that message, so there's no single solution you can find from just that error. The "parent transid verify failed" is a much better indication of what's happened here, and the small difference in transid numbers would indicate that -orecovery might actually have a chance of working. Hugo. > uname -a: > Linux Computer 4.2.0-22-generic #27-Ubuntu SMP Thu Dec 17 22:57:08 UTC > 2015 x86_64 x86_64 x86_64 GNU/Linux > > btrfs fi show: > Label: none uuid: b0486700-ff9f-4979-8735-257ff1428a0d > Total devices 1 FS bytes used 290.37GiB > devid 1 size 301.32GiB used 295.04GiB path /dev/sda8 > > Thanks in advance for any help, > Radek -- Hugo Mills | Always be sincere, whether you mean it or not. hugo@... carfax.org.uk | http://carfax.org.uk/ | Flanders & Swann PGP: E2AB1DE4 | The Reluctant Cannibal
Attachment:
signature.asc
Description: Digital signature
