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 such as DiskTracker 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. All these seemingly magical features do exact a price: you have to populate the Drobo with considerably more gigabytes than what shows up as available to you on your Mac’s desktop.
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 color (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 ten 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 adapter; unlike other drive bays, the Drobo lacks a dedicated power switch.
The Drobo is intended to be left plugged into the wall, and like most drives, it enters a low-power state when activity has ceased, though I would have preferred integrated AC power rather than the separate power brick it ships with. To get a ballpark estimate for how much usable capacity you can expect to get from four drives, add the total capacity of the three smallest drives and subtract the capacity of the largest. A more accurate total can be calculated on a Web page at drobo.com, which lets you interactively populate a virtual Drobo with drives of various capacities.
Getting the Drobo up and running is fairly straightforward, courtesy of a large, illustrated quick-setup card that greets you as you open the box. The numbered steps instruct you to insert the hard drive mechanisms, plug in the supplied power adapter, connect the 7-foot USB cable to your Mac, and initialize the Drobo using OS X’s Disk Utility. Although installing the Drobo’s supplied Dashboard utility (note that this is not an OS X Dashboard widget) isn’t necessary to begin using the drive bay, the utility delivers critical alerts when the Drobo requires your attention. It also provides a pie-chart view of how much storage is actually available. The Drobo always reports to your computer that you are working with a 2TB drive, even though you may only have 240GB of total hard drive space currently installed. This means that you can’t trust the Finder for an accurate picture of how much space you have left, but instead must rely on the Dashboard utility. This is all part of the Drobo’s cleverness, which allows you perform such stunts as adding another drive right in the middle of performing a backup without crashing the entire system.
One of the disappointments of the Drobo is that you can fill it up with speedy SATA drives, only to be hamstrung by the relatively pokey performance of the USB connection. This makes it less suited for use as a Photoshop scratch disk and more appropriate for storing incremental backups that run over a period of hours. USB is also to blame for another limitation: regardless of the size of the individual mechanisms, volumes can be no larger than 2TB, though the chances that you’ll need to back up a file larger than 2TB are slim.
Devices with built-in smarts have become pervasive, and the Drobo’s storage robot moniker pays tribute to the tricks it performs behind the scenes. However, calling it a robot seems a bit of a stretch. While it won’t rescue your kitten from a tree or your data from a burning building, the Drobo will allay your fears about the safety of your data. And with the Drobo, adding more hard drive space is like building a new wing onto your house without disturbing the contents of any of the existing rooms. The Drobo’s use of USB rather than the much faster FireWire 800 limits it to the niche of personal desktop storage, and if you’re in an environment where you routinely share large data files with others, then look elsewhere. However, if you’re after a safe and easy personal backup solution, the Drobo is an attractive solution.
Jeffy Milstead is a Macworld Lab alumnus and writer living in San Francisco.