I transferred files from 640GB (bay 2, volume 2) to PC.
Popped 2TB into Bay 2, logged in started process and it hung up on "formatting new volume". Pulled out 1TB from bay 1, put in 2TB only (read this on forum, somebody else having same issue).... drive not recognized. Pulled out 2 TB, popped it into PC, reformatted it, put it back in alone, formatted it and it was formatted as Volume 1. Put back in the 1TB and it became volume 2. Used internal backup to transfer files from volume 2 (originally volume 1) to the 2TB which is now called volume 1. Erased files and transferred back files from 640GB to the volume 2 1TB...so everything worked not as expected but ended up being exactly what I wanted.
Thanks for the help
Appreciated