The drill goes something like this: after getting perilously close to running out of hard disk space, you leap into spring cleaning mode and begin furiously corralling all of your important files in preparation for a marathon DVD burning session. Only then can you safely delete your culled files and reclaim drive space, assured in the knowledge that you have a backup safely tucked away. This still leaves you with a basic problem: keeping track of the particular DVD that contains a certain file or group of related project files. A cataloguing utility goes a long way toward helping you manage your backups, but wouldn’t life be much simpler if you didn’t have to keep reshuffling your data every time you were poised to run out of disk space?

The Drobo external USB storage device allows you to do exactly that, within limits. When you’re at the very precipice of running out of drive space, you can add a new drive, and the Drobo will deftly merge it with your existing storage pool without any need for further intervention on your part. Sound enticing? It gets better. The Drobo uses RAID-like redundancy, so your data is also protected against drive failure. If a hard drive goes south, your data is still safe because it is stored across all remaining drives. Simply pop in a replacement, and the Drobo will deputize the new drive.

With its all-black chassis, the Drobo looks like a small, sleek, subwoofer bass-reflex speaker. Removing the glossy black plastic faceplate, which is secured by magnets, reveals the bays into which you can slide up to four SATA hard disk mechanisms. A port is provided on the back of the chassis for attaching an anti-theft cable. Data Robotics sells the Drobo either without drives (this is the configuration we reviewed) or pre-populated with your choice of mix-and-match capacities (250GB, 500GB, 750GB, or 1TB mechanisms), though you’ll doubtless find better pricing on drives from other vendors. And although you can start with a single drive, you won’t get the benefit of the Drobo’s redundant data-safety features if you do.

The drives snap into place and are held by a retaining lever that also helps eject them. Each drive bay features a status LED that changes colour (to red, yellow, or green) or blinks according to what’s happening with that particular drive: normal operation, add a drive here soon, don’t remove the drive, add a drive here now, and drive failure. A legend describing these states is conveniently printed on the inside of the removable faceplate. A row of 10 blue LEDs along the bottom front of the Drobo’s exterior provides an indication of the current space left (in 10 percent increments), and separate power mode and USB activity lights sit above. Oddly, the power and USB lights are not visible with the faceplate affixed, requiring you to remove the faceplate if you want to be certain that the Drobo is ready to be safely unplugged from the power adaptor; unlike other drive bays, the Drobo lacks a dedicated power switch.