Hi drakon,
You don't mention what version of the 320 you have or the drives or how you are trying to format them, or your firmware version, but in general, if you are having trouble formating the drives, you might consider pulling them out and connecting them to a PC. Then delete all partitions and volumes and then reinstall and try again. If going with Raid 1, some people have trouble also. If that is your issue try just formating the first drive and then install the 2nd drive and see if you can convert to Raid 1. It's good to give all the details you can when looking for help. Good luck.