It seems like my cache is read only. Everything was fine but I can't access any of my Docker WebUIs anymore. I did some searching but I don't think I have the normal issue I've been seeing. There are no errors that I can tell.

 

root@NAS:~# btrfs balance start -dusage=75 /mnt/cache
ERROR: error during balancing '/mnt/cache': Read-only file system
There may be more info in syslog - try dmesg | tail
root@NAS:~# btrfs balance start -dusage=25 /mnt/cache
ERROR: error during balancing '/mnt/cache': Read-only file system
There may be more info in syslog - try dmesg | tail
root@NAS:~# btrfs dev stats -z /mnt/cache
[/dev/nvme0n1p1].write_io_errs    0
[/dev/nvme0n1p1].read_io_errs     0
[/dev/nvme0n1p1].flush_io_errs    0
[/dev/nvme0n1p1].corruption_errs  0
[/dev/nvme0n1p1].generation_errs  0
root@NAS:~# btrfs fi show /mnt/cache
Label: none  uuid: 3bdd2a6c-a527-4a33-838d-200712723d0c
        Total devices 1 FS bytes used 140.43GiB
        devid    1 size 465.76GiB used 163.02GiB path /dev/nvme0n1p1

Anyone have any ideas on what to try? This happened to me once before and I reformatted the cache. I'm hoping there is a better way without having to resetup my dockers.

nas-diagnostics-20200106-0253.zip

Edited January 6, 20206 yr by hybridtracer

You also have filesystem corruption on disk2 spamming the log, fix that first then reboot and post new diags.

https://wiki.unraid.net/Check_Disk_Filesystems#Checking_and_fixing_drives_in_the_webGui

I did a check an repair on disk 2. After reboot, the cache came up as unmountable. 

nas-diagnostics-20200106-1326.zip

Cache pool is corrupt, best bet is to re-format, there are some options here to try and recover data if needed.

Any thoughts on what may cause this? It is the second time it has happened. 

btrfs especially is very finicky with any hardware issues, add to that corruption also detected on a xfs filesystem and you likely have a hardware problem.