Cache Pool Unmountable (No file system)

[popc0rnx]

My dockers went down some time overnight and after a reboot, the cache pool (mirrored) is showing as "unmountable: no file system"

 

I tried following this guide but couldn't get either option to work: 

 

Option 1:

 

root@PandaNAS:~# mount -o rescue=all,ro /dev/nvme0n1 /temp
mount: /temp: wrong fs type, bad option, bad superblock on /dev/nvme0n1, missing codepage or helper program, or other error.
       dmesg(1) may have more information after failed mount system call.
root@PandaNAS:~# mount -o rescue=all,ro /dev/nvme1n1 /temp
mount: /temp: wrong fs type, bad option, bad superblock on /dev/nvme1n1, missing codepage or helper program, or other error.
       dmesg(1) may have more information after failed mount system call.

 

Option 2:

root@PandaNAS:/mnt/cache_ssd# btrfs restore -v /dev/nvme0n1 /mnt/cache_ssd/restore
No valid Btrfs found on /dev/nvme0n1
Could not open root, trying backup super
No valid Btrfs found on /dev/nvme0n1
Could not open root, trying backup super
No valid Btrfs found on /dev/nvme0n1
Could not open root, trying backup super
root@PandaNAS:/mnt/cache_ssd# btrfs restore -v /dev/nvme1n1 /mnt/cache_ssd/restore
No valid Btrfs found on /dev/nvme1n1
Could not open root, trying backup super
No valid Btrfs found on /dev/nvme1n1
Could not open root, trying backup super
No valid Btrfs found on /dev/nvme1n1
Could not open root, trying backup super

 

 

Here are some lines of interest from the logs:

Jul  1 14:05:20 PandaNAS kernel: BTRFS warning (device nvme0n1p1): checksum verify failed on 1594572800 wanted 0x07cabf78 found 0x74213188 level 0
Jul  1 14:05:20 PandaNAS kernel: BTRFS: error (device nvme0n1p1) in btrfs_replay_log:2500: errno=-5 IO failure (Failed to recover log tree)
Jul  1 14:05:20 PandaNAS root: mount: /mnt/cache_nvme: can't read superblock on /dev/nvme1n1p1.
Jul  1 14:05:20 PandaNAS root:        dmesg(1) may have more information after failed mount system call.
Jul  1 14:05:20 PandaNAS  emhttpd: shcmd (107): exit status: 32
Jul  1 14:05:20 PandaNAS  emhttpd: /mnt/cache_nvme mount error: No file system
Jul  1 14:05:20 PandaNAS  emhttpd: shcmd (108): umount /mnt/cache_nvme
Jul  1 14:05:20 PandaNAS kernel: BTRFS error (device nvme0n1p1: state E): open_ctree failed
Jul  1 14:05:20 PandaNAS root: umount: /mnt/cache_nvme: not mounted.

 

 

It seems like only nvme1n1 has a corrupted superblock? What's my options for recovery here? 

 

Thanks in advance!

pandanas-diagnostics-20230701-1425.zip

[JorgeB]

If the log tree is the main issue this may help:

 

btrfs rescue zero-log /dev/nvme1n1p1

 

If it does you should then run a scrub as data corruption was being detected before this.