I was able to clear the slot to none, then reboot with the array stopped. After the reboot, I was able to adjust the slot count back to 1 and start the array again. Not sure if this is a bug or not, but worth noting for others in the future.
I've been running with a single 1TB ssd in my cache pool for some time with an xfs partition. I was messing around with the pools and foolishly assigned an additional 2tb mechanical without first reading about pool expansion. Now that I've started the array, Unraid is asking to format the cache pool in order to make it mountable again which makes sense. However I'd rather remove that drive from the pool and set the drive count to 1 again so I can recover the contents of the cache (and probably pair more suitable drives together). Unfortunately, I seem to be locked in this state now where I can't remove the second drive.
Is there any where to clean this up without moving forward and formatting my cache?
Cheers!