I had added an extra drive to my pool and my cache starter while missing disk 2 on the cache. I have auto start. I did not realize it until a few days later since I use it mainly for the automatic Plex media. Today when I shutdown and reconnected the second ssd now my cache is coming out as unmountable. I tried to do the back up and btrfs restore command but it gives me error. 

syslog.txt

Should say anything I try to do in commands gives me an error of "No valid Btrfs found on /dev/nvme0n1"

Can you share your diagnostics on your next post ?

go to Tools / Diagnostics

There are some recovery options here.

I ended up just reformatting the drive after trying all options that I can find in the forum. Kind of needed plex to be working again and I was leaving out of town so just went ahead an reinstall all docker and VM learned.

 

Thanks for the replies