By cloning I meant copying files from the bad drive to the good drive (if, like you mentioned, I have time to do that). I do not have duplication enabled.
Thank you for the reply!
In my use for a Plex server I have 3 16-18TB drives in a 4 bay TerraMaster HDD enclosure. They were originally set up with say TV on 1 drive and movies on a 2nd drive. Now I have added the TerraMaster and an additional 18TB drive with all 3 in a drive pool and equally balanced. My question is what do I do if 1 of the drives starts giving me symptoms that it is failing? Is it as simple as cloning the contents from the failing drive to a new drive?