Fix Common Problems is reporting a "Cache unmountable: wrong or no filesystem" warning for all of my shares. Attaching diagnostics. 

I am running the latest stable build of unRAID (6.11.5). I'm not sure what do do/check. My cache drive is an NVME SSD, about 2 or 3 years old. For the past few months I've been getting errors every few weeks saying that the cache was full or read-only, but neither was the case so I'd reboot and that seemed to solve the issue. Today I did the same and now getting the below warnings.

 

Screenshots of my settings:

unraid-diagnostics-20230529-1610.zip

Edited May 30, 20233 yr by mark2741
solved

The syslog shows:

May 29 16:07:45 unRAID root: mount: /mnt/cache: can't read superblock on /dev/sdc1.

and the cache device not mounting which explains your symptoms.   It is 

 

hopefully @JorgeB might give you best achieve on recovering from this.

Cache fs has checksum errors, this may indicate a RAM problem, you can try zeroing the log in case that's the only/main problem:

 

btrfs rescue zero-log /dev/sdc1

 

Thank you @JorgeB. I ran that command and then did a reboot and it seems to have cleared the prior warnings. But now am seeing the errors below again when I run FCP. This is what I saw before a couple or few times over the last few months, but a reboot would (temporarily) seem to fix it.

 

 

Looking at the Docker page I see these:

 

 

The cache has plenty of spare space:

 

When I click the Container Size button I see these, which doesn't look right to my unskilled eye:

 

unraid-diagnostics-20230530-0850.zip

Edited May 30, 20233 yr by mark2741
Added container size screenshots.

Docker image is corrupt, delete and re-create.

I tried following the steps to delete and re-create but eventually just formatted the cache drive and that worked. Marking this as solved.