You would have 2 data sessions, each session would require 1 drive. It's sequential writes, so can't write with multiple sessions. For filesystem backups, you are best to land to a random disk and crank the sessions up higher than 4. I'd go to 10 if you have that many filesystems. At 10, you would get 4 producers, 4 consumers and some data session (resourceutil is weird in the way it works, but higher = more sessions assuming there's enough work).If you change it to 4, would it still send two file systems to the same drive? Or would it be one per drive and thus force another tape to be loaded?