* Fwd: Unable to mount degraded RAID5 [not found] <CAFDLS-CtnVDtD8d=Wtp0tVokKJ6pjptpX7MR862dThBJvSPC5g@mail.gmail.com> @ 2016-07-06 17:12 ` Gonzalo Gomez-Arrue Azpiazu 2016-07-06 18:19 ` Chris Murphy 0 siblings, 1 reply; 3+ messages in thread From: Gonzalo Gomez-Arrue Azpiazu @ 2016-07-06 17:12 UTC (permalink / raw) To: linux-btrfs Hello, I had a RAID5 with 3 disks and one failed; now the filesystem cannot be mounted. None of the recommendations that I found seem to work. The situation seems to be similar to this one: http://www.spinics.net/lists/linux-btrfs/msg56825.html Any suggestion on what to try next? Thanks a lot beforehand! sudo btrfs version btrfs-progs v4.4 uname -a Linux ubuntu 4.4.0-21-generic #37-Ubuntu SMP Mon Apr 18 18:33:37 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux sudo btrfs fi show warning, device 2 is missing checksum verify failed on 2339175972864 found A781ADC2 wanted 43621074 checksum verify failed on 2339175972864 found A781ADC2 wanted 43621074 bytenr mismatch, want=2339175972864, have=65536 Couldn't read chunk root Label: none uuid: 495efbc6-2f62-4cd7-962b-7ae3d0e929f1 Total devices 3 FS bytes used 1.29TiB devid 1 size 2.73TiB used 674.03GiB path /dev/sdc1 devid 3 size 2.73TiB used 674.03GiB path /dev/sdd1 *** Some devices missing sudo mount -t btrfs -o ro,degraded,recovery /dev/sdc1 /btrfs mount: wrong fs type, bad option, bad superblock on /dev/sdc1, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so. dmesg | tail [ 2440.036368] BTRFS info (device sdd1): allowing degraded mounts [ 2440.036383] BTRFS info (device sdd1): enabling auto recovery [ 2440.036390] BTRFS info (device sdd1): disk space caching is enabled [ 2440.037928] BTRFS warning (device sdd1): devid 2 uuid 0c7d7db2-6a27-4b19-937b-b6266ba81257 is missing [ 2440.652085] BTRFS info (device sdd1): bdev (null) errs: wr 1413, rd 362, flush 471, corrupt 0, gen 0 [ 2441.359066] BTRFS error (device sdd1): bad tree block start 0 833766391808 [ 2441.359306] BTRFS error (device sdd1): bad tree block start 0 833766391808 [ 2441.359330] BTRFS: Failed to read block groups: -5 [ 2441.383793] BTRFS: open_ctree failed sudo btrfs restore /dev/sdc1 /bkp warning, device 2 is missing checksum verify failed on 2339175972864 found A781ADC2 wanted 43621074 checksum verify failed on 2339175972864 found A781ADC2 wanted 43621074 bytenr mismatch, want=2339175972864, have=65536 Couldn't read chunk root Could not open root, trying backup super warning, device 2 is missing warning, device 3 is missing checksum verify failed on 2339175972864 found A781ADC2 wanted 43621074 checksum verify failed on 2339175972864 found A781ADC2 wanted 43621074 bytenr mismatch, want=2339175972864, have=65536 Couldn't read chunk root Could not open root, trying backup super warning, device 2 is missing warning, device 3 is missing checksum verify failed on 2339175972864 found A781ADC2 wanted 43621074 checksum verify failed on 2339175972864 found A781ADC2 wanted 43621074 bytenr mismatch, want=2339175972864, have=65536 Couldn't read chunk root Could not open root, trying backup super sudo btrfs-show-super -fa /dev/sdc1 http://sebsauvage.net/paste/?d79e9e9c385cf1a5#fNwoEj5o2aQ6T7nDl4vjrFqEJG0SHeVpmGknbbCVnd0= sudo btrfs-find-root /dev/sdc1 warning, device 2 is missing Couldn't read chunk root Open ctree failed ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Unable to mount degraded RAID5 2016-07-06 17:12 ` Fwd: Unable to mount degraded RAID5 Gonzalo Gomez-Arrue Azpiazu @ 2016-07-06 18:19 ` Chris Murphy 2016-07-07 12:24 ` Gonzalo Gomez-Arrue Azpiazu 0 siblings, 1 reply; 3+ messages in thread From: Chris Murphy @ 2016-07-06 18:19 UTC (permalink / raw) To: Gonzalo Gomez-Arrue Azpiazu; +Cc: Btrfs BTRFS On Wed, Jul 6, 2016 at 11:12 AM, Gonzalo Gomez-Arrue Azpiazu <ggomarr@gmail.com> wrote: > Hello, > > I had a RAID5 with 3 disks and one failed; now the filesystem cannot be mounted. > > None of the recommendations that I found seem to work. The situation > seems to be similar to this one: > http://www.spinics.net/lists/linux-btrfs/msg56825.html > > Any suggestion on what to try next? Basically if you are degraded *and* it runs into additional errors, then it's broken because raid5 only protects against one device error. The main problem is if it can't read the chunk root it's hard for any tool to recover data because the chunk tree mapping is vital to finding data. What do you get for: btrfs rescue super-recover -v /dev/sdc1 It's a problem with the chunk tree because all of your super blocks point to the same chunk tree root so there isn't another one to try. >sudo btrfs-find-root /dev/sdc1 >warning, device 2 is missing >Couldn't read chunk root >Open ctree failed It's bad news. I'm not even sure 'btrfs restore' can help this case. -- Chris Murphy ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Unable to mount degraded RAID5 2016-07-06 18:19 ` Chris Murphy @ 2016-07-07 12:24 ` Gonzalo Gomez-Arrue Azpiazu 0 siblings, 0 replies; 3+ messages in thread From: Gonzalo Gomez-Arrue Azpiazu @ 2016-07-07 12:24 UTC (permalink / raw) To: linux-btrfs Thanks a lot, your will to help out someone you do not know (and who is obviously way over his depth) is inspiring. This is what it says: btrfs rescue super-recover -v /dev/sdc1 All Devices: Device: id = 3, name = /dev/sdd1 Device: id = 1, name = /dev/sdc1 Before Recovering: [All good supers]: device name = /dev/sdd1 superblock bytenr = 65536 device name = /dev/sdd1 superblock bytenr = 67108864 device name = /dev/sdd1 superblock bytenr = 274877906944 device name = /dev/sdc1 superblock bytenr = 65536 device name = /dev/sdc1 superblock bytenr = 67108864 device name = /dev/sdc1 superblock bytenr = 274877906944 [All bad supers]: All supers are valid, no need to recover Any suggestion on what to do next? (again, really appreciated - I hope to be able to give back the support I am receiving at some point!) On Wed, Jul 6, 2016 at 9:19 PM, Chris Murphy <lists@colorremedies.com> wrote: > On Wed, Jul 6, 2016 at 11:12 AM, Gonzalo Gomez-Arrue Azpiazu > <ggomarr@gmail.com> wrote: >> Hello, >> >> I had a RAID5 with 3 disks and one failed; now the filesystem cannot be mounted. >> >> None of the recommendations that I found seem to work. The situation >> seems to be similar to this one: >> http://www.spinics.net/lists/linux-btrfs/msg56825.html >> >> Any suggestion on what to try next? > > Basically if you are degraded *and* it runs into additional errors, > then it's broken because raid5 only protects against one device error. > The main problem is if it can't read the chunk root it's hard for any > tool to recover data because the chunk tree mapping is vital to > finding data. > > What do you get for: > btrfs rescue super-recover -v /dev/sdc1 > > It's a problem with the chunk tree because all of your super blocks > point to the same chunk tree root so there isn't another one to try. > >>sudo btrfs-find-root /dev/sdc1 >>warning, device 2 is missing >>Couldn't read chunk root >>Open ctree failed > > It's bad news. I'm not even sure 'btrfs restore' can help this case. > > > -- > Chris Murphy ^ permalink raw reply [flat|nested] 3+ messages in thread
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[not found] <CAFDLS-CtnVDtD8d=Wtp0tVokKJ6pjptpX7MR862dThBJvSPC5g@mail.gmail.com>
2016-07-06 17:12 ` Fwd: Unable to mount degraded RAID5 Gonzalo Gomez-Arrue Azpiazu
2016-07-06 18:19 ` Chris Murphy
2016-07-07 12:24 ` Gonzalo Gomez-Arrue Azpiazu
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