BUFFALO HD-WIU2/R1 RAID Setup Utility 1.1

The RAID Utility allows you to configure your DriveStation Duo in several modes:
Independent Disks - Appears to your computer as two separate hard drives.
Spanning Mode - Appears to your computer as one large hard drive.
RAID 1 Mirror - Appears to your computer as a single drive. The second drive is an exact copy of the first drive, for redundancy.