I created a share for all my media files and set it to cache "yes".  Then I started transferring all my media files from my other machine (3TB) to this share. What ended up happening is that the cache drive (500GB) ran out of space which caused a whole bunch of problems. My dockers, also on the cache, re-mounted in read only which seemed to corrupt all my dockers.   I’ve since had to manually run the mover to free up space and then disable/reenable docker and finally reinstall the dock