On Wed, May 20, 2020 at 8:47 AM Panicx <panicx@xxxxxxxxx> wrote: > > Hello all, > > I had a recovery event a few days ago that completed, and as far as I > can tell, the array is clean. > root@xubuntu:/mnt/md0# mdadm -D /dev/mapper/vg0-lv0 > /dev/mapper/vg0-lv0: > Version : 1.2 > Creation Time : Mon Mar 30 19:44:30 2020 > Raid Level : raid5 > Array Size : 17571291136 (16757.29 GiB 17993.00 GB) > Used Dev Size : unknown > Raid Devices : 4 > Total Devices : 4 > Persistence : Superblock is persistent > > Intent Bitmap : Internal > > Update Time : Tue May 19 19:04:43 2020 > State : clean > Active Devices : 4 > Working Devices : 4 > Failed Devices : 0 > Spare Devices : 0 > > Layout : left-symmetric > Chunk Size : 128K > > Name : TNAS-2CC8E6:UTOSUSER-X86-S64 > UUID : cc80e7cd:c6b902c4:ef36b897:409e8f96 > Events : 18518 > > Number Major Minor RaidDevice State > 0 8 20 0 active sync /dev/sdb4 > 1 8 36 1 active sync /dev/sdc4 > 2 8 52 2 active sync /dev/sdd4 > 4 8 4 3 active sync /dev/sda4 > > I cannot mount it: > root@xubuntu:/mnt/md0# mount -t btrfs /dev/mapper/vg0-lv0 /mnt/md0/ > mount: /mnt/md0: wrong fs type, bad option, bad superblock on > /dev/mapper/vg0-lv0, missing codepage or helper program, or other > error. > > I cannot check it: > root@xubuntu:/mnt/md0# btrfsck /dev/mapper/vg0-lv0 > bytenr mismatch, want=441707118592, have=0 > Couldn't read tree root > ERROR: cannot open file system > > I cannot mount it readonly with the backuproot option, either: > root@xubuntu:/mnt/md0# mount -t btrfs -o ro,usebackuproot > /dev/mapper/vg0-lv0 /mnt/md0/ > mount: /mnt/md0: wrong fs type, bad option, bad superblock on > /dev/mapper/vg0-lv0, missing codepage or helper program, or other > error. > > Please help :) I'd like to get some baby photos/vids out of that > array before I call it a lost cause. Some of the photos are for > babies that aren't here anymore, and they are all I have. > > root@xubuntu:/mnt/md0# uname -a > Linux xubuntu 4.15.0-20-generic #21-Ubuntu SMP Tue Apr 24 06:15:38 UTC > 2018 i686 i686 i686 GNU/Linux > root@xubuntu:/mnt/md0# btrfs --version > btrfs-progs v4.15.1 > root@xubuntu:/mnt/md0# btrfs fi show > Label: none uuid: 9ef00e00-ea8a-4b29-b8b1-4ce6e85a7e7f > Total devices 1 FS bytes used 5.59TiB > devid 1 size 16.36TiB used 5.64TiB path /dev/mapper/vg0-lv0 > ## Note: I cannot mount the filesystem: > root@xubuntu:/mnt/md0# btrfs fi df /mnt/md0 > ERROR: not a btrfs filesystem: /mnt/md0 I strongly advise not doing anything that changes things on disk. Repairs will do writes. You need to be certain you understand the problem before proceeding with any repair. # btrfs rescue super -v /anydevice/ # btrfs insp dump-s /anydevice/ This won't fix anything but will state if any supers are found and if they're good or bad, and then print one of them. I suspect that the raid has not in fact been properly resumed and you will need very careful and explicit advice from the linux-raid@ list. Tell them everything that happened from the creation of the array, to the problem that happened, to any fixes you attempted. Many data loss cases involving raid are caused by users assuming a repair that is not indicated and the repair attempt makes data recovery impossible. -- Chris Murphy
