Earlier today I had my cache drive start going read-only. After stopping and restarting the array it would work for a few minutes and then go read-only again. I tried doing a btrfs repair but that didn't help. I figured my drive was failing so I pulled it out, replaced it with another SSD that I knew worked and restored from backup. Well, about 6 hours later the second drive started doing the same thing. However, now I can't even get that second drive to mount at all. It currently says "Unmountable: No file system"

 

I looked at my syslog and there are all kinds of errors from btrfs in there but I don't know what to do about them. I have attached my diagnostics from when the cache drive went read-only.

tower-diagnostics-20181124-2358.zip

Server is segfaulting, you should run memtest.

 

After and if there's important data on the cache device you can use this to try and recover before reformatting:

https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=543490

 

Ok, I'll give memtest a try. Thanks.