Do you have backups of everything important and irreplaceable?
If you don't have a backup server might make sense to keep the old server as a backup server.
If you need to transfer more than cache can hold, don't cache. Mover is intended for idle time. It is impossible to move from fast cache to slow array as fast as you can write to cache.
Yes
Others have been mentioned but that is the one that always comes to mind.
This google search should give you some other threads about that:
UFS Explorer threads on Unraid forum
Same ata4 resets you had earlier. Seems to be referring to disk3. Check connections.
Shouldn't cause crash though. Something else is probably going on.
Usual advice is to boot in SAFE mode with Docker and VM Manager disabled and let it run like that for a while to see if it still crashes.
You can make a backup of your configuration by putting your flash drive in your PC and copying the config folder.
Then reformat your flash drive, put a new install of Unraid on it, and copy your config folder from your backup.
That seems to have worked. Hadn't been backing up anything in appdata for months, just copies of my templates, many that I don't even use anymore. I'll clean those up.
Here it is under the shares section instead of storage management.
https://docs.unraid.net/unraid-os/manual/shares/user-shares/#moving-files-from-a-pool-cache-to-the-array
Storage management seemed the more logical place to look for this since the question wasn't really about any specific user share.
Nothing explained so far is helping me to understand what I need to change. Do I need to specify /mnt/fast/appdata for the Appdata source instead of /mnt/user/appdata?
Did it ever say your disks were unmountable?
Probably someone reformatted your array disks but nothing in those diagnostics shows what happened.
Is your server on the internet?
Do you have older diagnostics or syslogs?
Do you still have the original disks?
Don't see anything about RAM in that syslog, but problem communicating with some disk. Can't tell which without more context though.
Attach Diagnostics to your NEXT post in this thread.