Degraded volume silently fails to mount
Hi list,
I've got a 4 disk raid1 volume that has one failed disk. I have so far been unable to mount it in degraded mode, but the failure is that "mount" silently does nothing.
# btrfs fi sh warning devid 2 not found already Label: 'seneca' uuid: b9da07f5-c0fd-45ad-861b-d1bcad6cbf4c Total devices 4 FS bytes used 581.71GiB devid 1 size 931.51GiB used 334.02GiB path /dev/mapper/luks-seneca-1 devid 3 size 931.51GiB used 334.01GiB path /dev/mapper/luks-seneca-3 devid 4 size 931.51GiB used 334.01GiB path /dev/mapper/luks-seneca-4 *** Some devices missing
Btrfs v3.18.1
# mount -t btrfs -o degraded /dev/mapper/luks-seneca-1 /seneca # echo $? 0 # ls /seneca/ # grep seneca /proc/mounts # dmesg |tail [ 84.955467] BTRFS: device label seneca devid 1 transid 1753 /dev/dm-4 [ 87.926347] BTRFS: device label seneca devid 4 transid 1753 /dev/dm-5 [ 107.069109] BTRFS: device label seneca devid 3 transid 1753 /dev/dm-6 [ 195.267046] BTRFS info (device dm-6): allowing degraded mounts [ 195.267094] BTRFS info (device dm-6): disk space caching is enabled [ 195.267133] BTRFS: has skinny extents [ 195.277615] BTRFS warning (device dm-6): devid 2 missing [ 781.160250] BTRFS info (device dm-6): allowing degraded mounts [ 781.160270] BTRFS info (device dm-6): disk space caching is enabled [ 781.160286] BTRFS: has skinny extents # uname -a Linux ambrosia.homeslice 3.19.3-200.fc21.x86_64 #1 SMP Thu Mar 26 21:39:42 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux # btrfs --version Btrfs v3.18.1
Any ideas?
Quoted 5 lines · Michael Tharp
Hi list,
I've got a 4 disk raid1 volume that has one failed disk. I have so far been unable to mount it in degraded mode, but the failure is that "mount" silently does nothing.
Check to see if systemd is unmounting it immediately after
mount. This seems to be the usual reason for silent failures to mount an FS these days.
Hugo.
Quoted 34 lines
# btrfs fi sh warning devid 2 not found already Label: 'seneca' uuid: b9da07f5-c0fd-45ad-861b-d1bcad6cbf4c Total devices 4 FS bytes used 581.71GiB devid 1 size 931.51GiB used 334.02GiB path /dev/mapper/luks-seneca-1 devid 3 size 931.51GiB used 334.01GiB path /dev/mapper/luks-seneca-3 devid 4 size 931.51GiB used 334.01GiB path /dev/mapper/luks-seneca-4 *** Some devices missingBtrfs v3.18.1
# mount -t btrfs -o degraded /dev/mapper/luks-seneca-1 /seneca # echo $? 0 # ls /seneca/ # grep seneca /proc/mounts # dmesg |tail [ 84.955467] BTRFS: device label seneca devid 1 transid 1753 /dev/dm-4 [ 87.926347] BTRFS: device label seneca devid 4 transid 1753 /dev/dm-5 [ 107.069109] BTRFS: device label seneca devid 3 transid 1753 /dev/dm-6 [ 195.267046] BTRFS info (device dm-6): allowing degraded mounts [ 195.267094] BTRFS info (device dm-6): disk space caching is enabled [ 195.267133] BTRFS: has skinny extents [ 195.277615] BTRFS warning (device dm-6): devid 2 missing [ 781.160250] BTRFS info (device dm-6): allowing degraded mounts [ 781.160270] BTRFS info (device dm-6): disk space caching is enabled [ 781.160286] BTRFS: has skinny extents # uname -a Linux ambrosia.homeslice 3.19.3-200.fc21.x86_64 #1 SMP Thu Mar 26 21:39:42 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux # btrfs --version Btrfs v3.18.1Any ideas?
Signature · 4 lines
Hugo Mills | What's a Nazgûl like you doing in a place like this? hugo@... carfax.org.uk | http://carfax.org.uk/ | PGP: E2AB1DE4 | Illiad
Quoted 10 lines · Hugo Mills
Quoted 5 lines · Michael Tharp
Hi list,
I've got a 4 disk raid1 volume that has one failed disk. I have so far been unable to mount it in degraded mode, but the failure is that "mount" silently does nothing.
Check to see if systemd is unmounting it immediately after
mount. This seems to be the usual reason for silent failures to mount an FS these days.
Sigh, that was it. Thanks. Faith in btrfs restored.
I had a custom unit file because the generated ones weren't getting the LUKS device dependencies correct. When the drive failed I commented out the fstab and crypttab entries but forgot about the custom unit file.