Basically Drobo is a USB drive enclosure that houses 4 empty bays. Each one of these bays will accept a 3.5 inch SATA 1 or SATA 2 type drive of any capacity from any vendor. Drobo can recover your data in case of disk failure.
You need no special tools to set up Drobo. All you have to do is to insert a SATA drive into one of the four drives and connect Drobo to your PC through a USB 2.0 port. Power up the PC and Drobo will start backing up your data.
Price range: $349 - $499
Pros:
Can work with all 3.5 inch SATA drives
Runs quietly
Cons:
Costly
