RAID-1 on the 2-bay ShareCenter creates a mirror of all data stored on the unit. Data stored on Volume_1 (HDD1) is copied in real time to Volume_2 (HDD2). By design, you will not have access to see Volume_2 since this data is simply a real time copy (mirror) of the data located on Volume_1. As such, The ShareCenter hides Volume_2 from users.