Hi everyone and sorry for my bad English.

I have a pool with 8 completely full disks and I would like to disconnect a disk from the pool because I need it on another PC. the pool is in btfrs single, does anyone have an idea how I can do it, even buying maybe another disc? Thank you

If it is a pool you can just remove it.   Note that any contents you want to keep should first be copied elsewhere.    Also anything referencing it (shares, docker containers, VMs) would need their settings adjusted appropriately.

sorry, I explained myself poorly. I have to remove one disk at a time to try to recover the data. Unfortunately I don't have any other discs to put them on at the moment.

Do you really mean pool or array? Post a screenshot or the diagnostics.

I'll attach the diagnostics and try to explain myself better.

Basically I have to move the disks from Unraid to a Windows PC and I would like to use them individually without losing the data (or at least limiting the loss). For me it might also be fine to delete a little bit of data to allow me to free up one disk at a time until I remove them all.

tower-diagnostics-20241202-1839.zip

GUI doesn't allow removing disks from single profile pools, only redundant pools, you could do it manually using the CLI, one disk at a time, but would need to free up some space before removing each disk.

Yes.... it would be perfect. You totally nailed what I meant. Even freeing up 20TB of space is fine for me. the only thing is that I need to be guided step by step because I have no idea how to do it. thanks so much for the help.

After freeing enough space, and make sure you leave at least many GBs extra space, ideally 1TB to avoid issues during the balance, type:

 

btrfs dev del /dev/sdX1 /mnt/plot_share

 

Replace X with one of the pool disks, wait for the data to be balanced, and the disk removed, it will be done when you get the cursor back, if you don't need to stop the array, you can repeat for the next disk, free up space, remove the disk, if you need to stop the array, you need to er-import the pool without the removed disk(s), to do that, stop array, unassign all pool devices, start array, stop array, reassign only the remaining pool devices, start array to import the pool, and you can continue removing another device.

OK perfect.

I'll try in the next few days and update you on how it went, thanks again.

Do you have any other advice for me?

Not really, other than you can monitor the progress by looking at:

 

btrfs fi usage -T /mnt/plot_share

 

You will see the data being moved from the device you are removing to the other ones.

I'll be back here to write.

The process is slow (2 days to move the data and 2 days to erase the disk). In any case, I mark it as solved and thanks again for the solution 😉.