(6.2.4) Cache Drive reporting "No Space Left On Disk"

I have been trying to get to the bottom of this for a few weeks now. I have a 500GB Cache drive that has about 300GB of free space on it. For some reason Unraid is reporting it as full. It is stopping SAB and pretty much all of my dockers at the moment. From everything I can tell there is plenty of space available. Here is the part that is really confusing me. If I go and delete a partial download from SAB, say 2 GB or so, the free space being reported in SAB jumps to 300GB+. As so

By clearzero, February 6, 2017
10 replies

This is the problem: All space on the device is allocated, no new chunks can br created, try to delete something and running a balance: btrfs balance start -dusage=5 /mnt/cache If you get and out of space error, try deleting more files, the bigger the better, if the balances succeeds you'll get the allocated but unused space back.