Hi all,
I appreciate that I am incredibly uneducated regarding Unraid, so I'm sorry in advance for what may be obvious questions.

A few days ago, my server went through a power loss, not the first time so I didn't think it would be a big deal.

Powered it back on and let the server go through a parity check, to which it found 8 errors, and fixed them.
However when I tried to access some of my docker images, they had been fully reset. Looking into it a little bit, it seems a lot of my Appdata files had been reset and "created" on the day I restarted the server.

There is some things on there that I would really love to get back if possible, like a Minecraft server for my family.

Is there anything I can do now to restore that appdata data? Or is that gone for good...

Attach Diagnostics ZIP to your NEXT post in this thread.

Here are the Diagnostics:

ginger-server-diagnostics-20260403-1325.zip

I am also now aware that the server is several updates behind, but I didn't want to change anything until after I tried to solve this.

Have you never had a cache drive?

No, I haven't. I was told it wasn't needed when I built the server... I'm guessing now that it probably was? lol

8 hours ago, redguy212 said:

No, I haven't. I was told it wasn't needed when I built the server... I'm guessing now that it probably was? lol

A cache drive is never needed. It is normally used to increase the performance of VMs and Docker containers and to improve the perceived performance of writing new files to shares by shifting the writing of them to the array to an overnight task.

No obvious reason from your description why the containers should have been reset.

Having said that anything important should be backed up - parity is not a substitute for backup.

1 hour ago, itimpi said:

cache drive is never needed. It is normally used to increase the performance of VMs and Docker containers

I thought perhaps cache had all your docker files as it usually does, but now it is missing for some reason. That would be an explanation for why appdata had to be recreated from scratch.

If you never had cache, nothing in your diagnostics or your descripton that would explain it.

Another possibility is your appdata wasn't on actual storage. In which case, it would not survive reboot. Have you ever had appdata that wasn't new after rebooting?

16 minutes ago, trurl said:

Another possibility is your appdata wasn't on actual storage. In which case, it would not survive reboot. Have you ever had appdata that wasn't new after rebooting?

Good point. If any docker container had something mapped to /mnt/cache then that location would be created in RAM when the container starts and then appdata files placed there as well with the current settings of the ‘appdata’ share. Such files would not survive a reboot.

If there is no cache pool then the settings for the ‘appdata’ share should be changed so that Primary Storage is the array and there is nothing set for Secondary storage.

In addition if any docker container had something mapped to a /mnt/cache location then the mapping should instead be changed to use a /mnt/user location which works regardless of whether the files are on the array or a pool.

On 4/4/2026 at 12:32 AM, trurl said:

Another possibility is your appdata wasn't on actual storage. In which case, it would not survive reboot. Have you ever had appdata that wasn't new after rebooting?

The Server has gone through multiple reboots up to this point, and I've never had this issue. Super confused as to why this happened...

Maybe there were some things mapped to /mnt/cache, but surely that would have come up in previous reboots?

This isn't a new server, its been running for at least a year now.

I think I'm just going to cut my losses and rebuild from scratch. This time with an appdata backup.

Thanks for all the help!