Re: RAID1 fails to recover chunk tree

[Anand Jain <Anand.Jain@oracle.com>]

  'mount degraded,ro'
   see if there is any non-zero non-raid1 group profile.



On 10/29/14 04:32, Zack Coffey wrote:
> Revisit of a previous issue. Setup a single 640GB drive with BTRFS and
> compression. This was not a system drive, just a place to put random
> junk.
>
> Made a RAID1 with another drive of just the metadata. Was in
> that state for less than 12 hours-ish, removed the second drive and
> now cannot get to any data on the original drive. Data remained single
> while only metadata was RAID1.
>
> Single drive btrfs was made on Ubuntu with kernel 3.13.0 and tools
> 3.12.
>
> $ sudo mount -o degraded /dev/sdc1 /media/Data/
> 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
> [45353.869448] KBD BUG in
> ../../../../../../../../
> drivers/2d/lnx/fgl/drm/kernel/
> gal.c at line:
> 304!
> [45353.901511] KBD BUG in
> ../../../../../../../../
> drivers/2d/lnx/fgl/drm/kernel/gal.c at line:
> 304!
> [45353.901666] KBD BUG in
> ../../../../../../../../drivers/2d/lnx/fgl/drm/kernel/gal.c at line:
> 304!
> [45354.148488] KBD BUG in
> ../../../../../../../../drivers/2d/lnx/fgl/drm/kernel/gal.c at line:
> 304!
> [45354.148573] KBD BUG in
> ../../../../../../../../drivers/2d/lnx/fgl/drm/kernel/gal.c at line:
> 304!
> [46241.155350] btrfs: device fsid bd78815a-802b-43e2-8387-fc6ab4237d67
> devid 1 transid 60944 /dev/sdc1
> [46241.155923] btrfs: allowing degraded mounts
> [46241.155927] btrfs: disk space caching is enabled
> [46241.159436] btrfs: failed to read chunk root on sdc1
> [46241.177815] btrfs: open_ctree failed
>
> $ btrfs-show-super /dev/sdc1
> superblock: bytenr=65536, device=/dev/sdc1
> ------------------------------
> ---------------------------
> csum                    0x93bcb1b5 [match]
> bytenr                  65536
> flags                   0x1
> magic                   _BHRfS_M [match]
> fsid                    bd78815a-802b-43e2-8387-fc6ab4237d67
> label
> generation              60944
> root                    909586694144
> sys_array_size          97
> chunk_root_generation   60938
> root_level              1
> chunk_root              911673917440
> chunk_root_level        1
> log_root                0
> log_root_transid        0
> log_root_level          0
> total_bytes             1115871535104
> bytes_used              321833435136
> sectorsize              4096
> nodesize                4096
> leafsize                4096
> stripesize              4096
> root_dir                6
> num_devices             2
> compat_flags            0x0
> compat_ro_flags         0x0
> incompat_flags          0x9
> csum_type               0
> csum_size               4
> cache_generation        60944
> uuid_tree_generation    60944
> dev_item.uuid           d82b2027-17b6-4513-a86d-9227a42d7ed1
> dev_item.fsid           bd78815a-802b-43e2-8387-fc6ab4237d67 [match]
> dev_item.type           0
> dev_item.total_bytes    615763673088
> dev_item.bytes_used     324270030848
> dev_item.io_align       4096
> dev_item.io_width       4096
> dev_item.sector_size    4096
> dev_item.devid          1
> dev_item.dev_group      0
> dev_item.seek_speed     0
> dev_item.bandwidth      0
> dev_item.generation     0
>
>
> $ sudo btrfs device add -f /dev/sdh1 /dev/sdc1
> ERROR: error adding the device '/dev/sdh1' - Inappropriate ioctl for device
>
> $ sudo btrfs device delete missing /dev/sdc1
> ERROR: error removing the device 'missing' - Inappropriate ioctl for device
>
> $ sudo mount -o degraded,defaults,compress=lzo /dev/sdc1 /media/Data/
> 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
> [106991.655384] btrfs: device fsid
> bd78815a-802b-43e2-8387-fc6ab4237d67 devid 1 transid 60944 /dev/sdc1
> [106991.665066] btrfs: device fsid
> bd78815a-802b-43e2-8387-fc6ab4237d67 devid 1 transid 60944 /dev/sdc1
> [107019.954397] btrfs: device fsid
> bd78815a-802b-43e2-8387-fc6ab4237d67 devid 1 transid 60944 /dev/sdc1
> [107019.962009] btrfs: device fsid
> bd78815a-802b-43e2-8387-fc6ab4237d67 devid 1 transid 60944 /dev/sdc1
> [107070.124927] btrfs: device fsid
> bd78815a-802b-43e2-8387-fc6ab4237d67 devid 1 transid 60944 /dev/sdc1
> [107070.126475] btrfs: allowing degraded mounts
> [107070.126479] btrfs: use lzo compression
> [107070.126480] btrfs: disk space caching is enabled
> [107070.127254] btrfs: failed to read chunk root on sdc1
> [107070.142983] btrfs: open_ctree failed
>
> $ sudo btrfs rescue super-recover -v /dev/sdc1
> All Devices:
>          Device: id = 1, name = /dev/sdc1
>
> Before Recovering:
>          [All good supers]:
>                  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
>
> $ btrfs rescue chunk-recover -v /dev/sdc1
> <<snipped>>
> Chunk: start = 860100755456, len = 1073741824, type = 1, num_stripes = 1
>        Stripes list:
>        [ 0] Stripe: devid = 1, offset = 26877100032
>        No block group.
>        No device extent.
>    Chunk: start = 861174497280, len = 1073741824, type = 1, num_stripes = 1
>        Stripes list:
>        [ 0] Stripe: devid = 1, offset = 27950841856
>        No block group.
>        No device extent.
>
> Total Chunks:   333
>    Heathy:       305
>    Bad:  28
>
> Orphan Block Groups:
>    Block Group: start = 872985657344, len = 1073741824, flag = 4
>    Block Group: start = 911673917440, len = 33554432, flag = 2
>    Block Group: start = 911707471872, len = 1073741824, flag = 4
>
> Orphan Device Extents:
>    Device extent: devid = 2, start = 2182086656, len = 33554432, chunk
> offset = 911673917440
>    Device extent: devid = 2, start = 2215641088, len = 1073741824,
> chunk offset = 911707471872
> Fail to recover the chunk tree.
> <</snipped>>
>
> Here's the full snipped paste: http://pastebin.com/fEm3Gup7
>
> Now I'm on openSUSE Tumbleweed (kernel 3.17). Still get the same
> result from 'chunk-recover'. There's 305 healthy chunks, is there
> anyway to recover that data and forget about the bad ones?
>
> A good portion of the data on that drive was backed up, but some
> wasn't. My fault, I've learned. Can I get anything back from that
> drive?
>
> Thanks
> --
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