I had this happen to me... I accidentally allowed a pool to fill up to capacity and couldn't do anything with it because deleting files wouldn't free space due

I had this happen to me... I accidentally allowed a pool to fill up to capacity and couldn't do anything with it because deleting files wouldn't free space due to snapshots and the commands to delete snapshots wouldn't work. Then added a disk to it to try to recover. That worked, but only after adding a disk did I realize that I couldn't shrink the pool down again. I ended up moving the whole thing off to a new disk cluster and back again. Really painful.