So... I had a 2TB drive (nearly full) in the right bay, "standard" format.  
- I added a second 2TB drive in the left bay.  
- Powered up and the 321 recognized it and offered to format it.  I said OK.  It chugged along.  I went and had dinner.  
- When I got back it was offering "restart".  When it restarted, it offered to format the drive again and the drive light was not the usual blue.  Without thinking, I clicked "next".
- Now I appear to have 2 blank drives!!!!  And, of course... in a hurry and with nothing like another 2TB drive to back up to.... and believing the "we won't harm your existing data" message... I am so screwed!
I've checked both volumes... they're both blank.
Help!?!?!
(And yes... I am having a bad day with this thing.  FWIW... I am no newb to this kind of stuff.  Just out in the weeds looking for a guide to bring me back.)
/a