I want to go down from two cache disks to one.

 

So I stopped the array, unassigned the second drive, restarted the array again. Cache 2 now showed as "Not installed", which was expected.

To remove this, I then stopped the array again, set number of slots to one, and started again - but after starting the array the "Not installed" Cache 2 is there again. How can I delete it?

 

After stopping the array, slots is set to two:

 

I move to "1" and start the array:

 

After the array has started, the "Not Installed" Slot is there again:

unraid-diagnostics-20250214-1234.zip

3 hours ago, Sabbi said:

Cache 2 now showed as "Not installed", which was expected.

IIRC it should have removed the pool device and converted the pool to single, possibly the removal failed, but since the server was rebooted cannot see, with the array started type:

 

btrfs dev del missing /mnt/cache

 

Then post new diags once that's done.

 

 

Does not seem to work:

 

root@Unraid:~# btrfs dev del missing /mnt/cache
ERROR: error removing device 'missing': unable to go below two devices on raid1

 

I also noted that the size is wrong (180GB), it's only a 120GB Drive. The drive removed was a 240GB.

Sorry, you must convert to single first:

 

btrfs balance start -dconvert=single -mconvert=dup /mnt/cache

 

then run the other command

I did issue both commands:

root@Unraid:~# btrfs balance start -dconvert=single -mconvert=dup /mnt/cache
Done, had to relocate 94 out of 94 chunks
root@Unraid:~# btrfs dev del missing /mnt/cache
root@Unraid:~#

 

(After the first command, the pool showed a size of 360GB, after the second it is back to 120GB).

 

Pool still shows the "not inststalled" device. I did not try to remove it as of now. You think the system is ready now to do so?

 

unraid-diagnostics-20250215-0951.zip

 

Edit: I've stopped the array, changed pool to one drive, now it's started without any errors. All good Thank you very much for your help.

Edited February 15, 20251 yr by Sabbi