Moving Library to NAS from VM

I setup a VM (running Ubuntu 16) on unraid to run Plex. Everything is great except, I now want to move my library/database outside the VM to the NAS (since the NAS only has 20GB). I found the instructions with the system override, which works great for local (within the VM) directories, but doesn't work if I refer to a mounted NAS location. I have the NAS location mounted in fstab, and have tried creating a matching plex:plex user/group on the NAS, but it always seems to go back to the /var/lib/plexmediaserver/Library location when I point to the NAS. Any suggestions