Ok on my unRAID server the main cache pool has a missing "device path". I also noticed that it is no longer in a RAID1 config.

I am not sure what happened but the funny thing is the currently "working disk" was throwing errors and I removed it to see if I could repair it using Partition Manager Pro. When I used Partition Manager it said the disk was "unformatted" so I formatted the disk to NTFS working on the assumption that when I put it back into the server, it would just have the contents rebuilt from the remain member disk in the pool. I put the disk back in, and there were no more errors and then I noticed that the pool was now "2TB" rather than the expected "1TB" (they are 2 x 1TB Crucial nVME units) but somehow the DATA is on the disk I removed... so very strange.

Is there a way for me to move the contents of the cache pool to the array, delete the cache pool, recreate it and then move the data back from the array back to the newly created cache pool ensuring that I have it set to RAID1 for redundancy/fault tolerance?

For the record I have a 2nd cache pool but I'm not using that for anything at the moment.

Edited October 20, 2025Oct 20 by thaoggamer
Marked as solved

Please post the diagnostics.

@JorgeB attached here.

galactica-diagnostics-20251020-2210.zip

Update:

Not sure if it will help but what I have now done is changed the shares that were set to Cache Only to be Cache and Array. Hopefully I don´t lose 2 parity disks in the next 48 hours

I have also added an updated Diagnostics file which takes into account above change.

galactica-diagnostics-20251020-2300.zip

With the array running type:

btrfs dev remove missing /mnt/starbuck

Once that's done, reimport the pool with the 2nd device only, the one being used (nvme1n1)

on main click on the first device for that pool and then "remove pool"

back on main, create a new pool with the same name and 1 slot

assign that pool device, leave the filesystem set to auto

start the array to import the pool

Pool should import as a single device, if all looks good, stop array change slots to 2 and add the other device to create a mirror.

Bloody Champion @JorgeB thank you very much for your help