My Book Mirror Edition 2TB - How do I know if mine is mirrored?

I just received a replacement External HD since I had to RMA my previous one for a disk failure.

Upon plugging in the new one I received, it only reads as 1TB, which I assume is good, since I want 2 mirrored 1TB drives.  However, how can I know for sure if these are in fact set as RAID 1 and mirrored?


download and run Drive Manager for Mac:

of for PC:

it will show you the drive’s Raid status, and allow you to change between Raid 0 and Raid 1, detailing the drive capacities for each option.

Thank you!  This is exactly what I was looking for.