Hi all

I recently had a massive issue when I tried to replace my cache disk, which stored appdata, domains & system, with a larger SSD.

When I moved the files to the array it all went very wrong and most of my appdata was lost and as a result most dockers failed and needed to be rebuilt completely.

I replaced the 500Gb SSD with a 2Tb SSD and recreated the lost data. This is currently stored at /mnt/user/appdata, /mnt/user/domains & /mnt/user/system.

After having to recreate most dockers and set them up again, the system has been working for a few months now - so I currently have a working system with an empty 2Tb cache disk.

I have a number of VMs and dockers which are running 24x7 and because they are currently on the main array, it keeps all the array disks (which have any docker/vm data on) spinning all the time.

This was the main reason that I originally installed a cache disk - to allow the array disks to spin down when not in use.

Because of the issue I had before, I have now installed 'Appdata Backup' and it is currently running - creating a backup on the main array.

My question is this... what is common practice for storing appdata, domains & system? Or can someone recommend what I should move to cache? In my setup is it best to move them back on to the cache disk?

If so, what is the correct way to do this, so I don't lose data again??

Also, as Appdata Backup is currently creating a backup of /mnt/user/appdata... if/when I move appdata to /mnt/cache/appdata should I just manually delete the /mnt/user/appdata backup from the backup location and create a new backup for /mnt/cache/appdata? Or, is there a way to notify Appdata Backup that the location has changed?

I want to do this over the New Year break as there will be no users accessing the server... so any help to avoid more massive downtime would be very much appreciated.

Thanks

Edited December 29, 2025Dec 29 by SliMat

I'm bumping this as I still have not moved appdata, domains & system onto the new 2Tb disk, so they are still on the array and the 2Tb SSD is empty.

Is there a tut, or a post which outlines the correct way to move these back onto the cache disk? I am wary having lost data when I tried to move them off the original SSD and dont want to end up with more downtime

Any advice / instructions greatly received.

Thanks

You can use this to move shares from array to pool or vice verssa:

https://forums.unraid.net/topic/46802-faq-for-unraid-v6/#findComment-511923

On 3/14/2026 at 12:07 PM, JorgeB said:

You can use this to move shares from array to pool or vice verssa:

https://forums.unraid.net/topic/46802-faq-for-unraid-v6/#findComment-511923

Thanks I will try this at the weekend when I can take it offline for a while.

On 3/14/2026 at 12:07 PM, JorgeB said:

You can use this to move shares from array to pool or vice verssa:

https://forums.unraid.net/topic/46802-faq-for-unraid-v6/#findComment-511923

Thanks @JorgeB - I have only just got round to doing this and mover has completed, but when I look at the shares, some of the data is still showing as being stored on array disks. So, I ran mover again and it finished straight away - but moved nothing more...

When I drill down in my Plex-Media-Server share, it shows several folders which are still holding data on the array;

Is this normal... if not, what do I need to do to correct this?

Thanks

Enable mover logging, run the mover, post the diagnostics.

It is worth checking if any of the files that will not move are actually duplicates as Mover will not overwrite existing files. If you have duplicates you need to manually decide which Copy to keep (typically the newest) and delete the other copy.

Nothing can move open files. Disable Docker and VM Manager in Settings, run Mover, wait for it to complete, then

Attach Diagnostics ZIP to your NEXT post in this thread.