Hello Ikarus_CT
Assuming these disks were new? I have found that disks formatted in a QNAP NAS will not format in an MD600 (many hours of frustration

) if you have a way of formatting these on/in a PC in NTFS, then I would do that, then insert them into the MD600, you must have two drives in before you power it on, it then goes through its bootup, flashing various LEDs, then if it begins the format you should see LEDs flashing left to right and back, sort of like the Knight Rider car!! This should complete in 10 to 15 minutes.
Cheers
Russ