I have a Btrfs filesystem using 6 partitionless disks in RAID1 that's failing to mount. I've tried the common recommended safe check options, but I haven't gotten the disk to mount at all, even with -o ro,recovery. If necessary, I can try to use the recovery to another filesystem, but I have around 18 TB of data on the filesystem that won't mount, so I'd like to avoid that if there's some other way of recovering it.
Versions: btrfs-progs v4.19.1 Linux localhost 4.20.6-arch1-1-ARCH #1 SMP PREEMPT Thu Jan 31 08:22:01 UTC 2019 x86_64 GNU/Linux Based on my understanding of how RAID1 works with Btrfs, I would expect a single disk failure to not prevent the volume from mounting entirely, but I'm only seeing one disk with errors according to dmesg output, maybe I'm misinterpreting it: [ 534.519437] BTRFS warning (device sdd): 'recovery' is deprecated, use 'usebackuproot' instead [ 534.519441] BTRFS info (device sdd): trying to use backup root at mount time [ 534.519443] BTRFS info (device sdd): disk space caching is enabled [ 534.519446] BTRFS info (device sdd): has skinny extents [ 536.306194] BTRFS info (device sdd): bdev /dev/sdc errs: wr 23038942, rd 22208378, flush 1, corrupt 29486730, gen 2933 [ 556.126928] BTRFS critical (device sdd): corrupt leaf: root=2 block=25540634836992 slot=45, unexpected item end, have 13882 expect 13898 [ 556.134767] BTRFS critical (device sdd): corrupt leaf: root=2 block=25540634836992 slot=45, unexpected item end, have 13882 expect 13898 [ 556.150278] BTRFS critical (device sdd): corrupt leaf: root=2 block=25540634836992 slot=45, unexpected item end, have 13882 expect 13898 [ 556.150310] BTRFS error (device sdd): failed to read block groups: -5 [ 556.216418] BTRFS error (device sdd): open_ctree failed If helpful, here is some lsblk output: NAME TYPE SIZE FSTYPE MOUNTPOINT UUID sda disk 111.8G ├─sda1 part 1.9M └─sda2 part 111.8G ext4 / c598dfdf-d6e7-47d3-888a-10f5f53fa338 sdb disk 7.3T btrfs 8f26ae2d-84b5-47d7-8f19-64b0ef5a481b sdc disk 7.3T btrfs 8f26ae2d-84b5-47d7-8f19-64b0ef5a481b sdd disk 7.3T btrfs 8f26ae2d-84b5-47d7-8f19-64b0ef5a481b sde disk 7.3T btrfs 8f26ae2d-84b5-47d7-8f19-64b0ef5a481b sdf disk 2.7T btrfs 8f26ae2d-84b5-47d7-8f19-64b0ef5a481b sdh disk 2.7T btrfs 8f26ae2d-84b5-47d7-8f19-64b0ef5a481b My main system partition on sda mounts fine and is usable to work with the btrfs filesystem that's having issues. Running "btrfs check /dev/sdb" exits with this: Opening filesystem to check... Incorrect offsets 13898 13882 ERROR: cannot open file system Also, "btrfs restore -Dv /dev/sdb /tmp" outputs some of the files on the filesystem but not all of them. I'm not sure if this is limited to the files on that physical disk, or if there's a bigger issue with the filesystem. I'm not sure what the best approach from here is, so any advice would be great.
