Data Robotics' new "data robot" Drobo is a fully-automated multidrive enclosure intended to make storage easy for small businesses.

Drobo, a storage appliance that sells in the US for $499 without drives (and will be available in the UK later this year), employs its own disk and storage virtualisation algorithms to give users many of the data redundancy benefits of RAID without RAID's complexity. With its own operating system, CPU and memory to power data handling smarts, the appliance allows you to swap failing drives in and out even as you continue working on your files.

"The technology is basically a replacement for RAID," said Daniel Stevenson, president of Data Robotics in Mountain View, California. With Drobo, the company wants to make data redundancy transparent and seamless to the consumer.

Plug Drobo into your system, and it's recognised as a USB mass storage device - no host software is required on your PC to read the drive. It's a direct-attached USB 2.0 unit with four Serial ATA drive bays that can handle drives with capacities of up to 1 terabyte each. Each bay has its own pop-out lever for easily removing a drive.

Drobo is what the company refers to as a "DataAware" device. It knows where each of block of data is stored on a disk, and its algorithms are more flexible than the RAID standards in wide use today. Together, these factors make it easier to manage a data device as one large "pool" of data, and for Drobo to monitor itself for data corruption and other issues that cause disk failure.

LED status lights use a simple, colour-coded green, yellow and red approach to informing you of Drobo's status - and more precisely, of the health of the individual drives inside Drobo. Drobo can interact with the Self-Monitoring Analysis and Reporting Technology (SMART) capabilities integrated on many hard drives.

Jim Schaff, director of marketing said, "We can then monitor bad sectors, and will proactively fail a disk," so you can replace the disk drive before any further failures happen and still come out with your data intact.

According to Schaff, if the status lights are green, your data is safe. If the lights turn yellow, it indicates that Drobo is at 85 percent capacity, and you need to replace a drive with a larger one. Unlike with RAID, Drobo will take advantage of whatever capacity drives you insert, regardless of whether or not the drive sizes are matched. Red indicates that your data is not being automatically protected, and that you should add or replace a drive immediately.

You can easily replace a drive by removing it. Drobo will let you continue working on your files even as you insert a new drive (no formatting required) into the drive bay, and wait for it to integrate with the system (a process that takes very little time compared to waiting for a drive to rebuild itself on a RAID system).

While Drobo will offer the data redundancy necessary to protect you against hardware failure, it won't protect against theft or catastrophic disaster. You may still want to keep a second copy of your data elsewhere, as a true backup.