Affordable external hard drives have made data storage and backup cheaper and simpler than ever, but like every other great technology, there's a catch.
At it's most basic, an external hard drive is not much more than a regular old laptop or desktop hard drive in a box. Add a little bit of circuitry to interface with the computer and voila! However, many of these solutions, particularly the network based models and the larger capacity models on the market at any given time, are actually a little more complicated than that.
These models incorporates a technology called RAID (Redundant Array Of Independent Disks) to provide increased perfomance, data redundancy, or in some cases just a bigger number on the outside of the box. RAID is actually an excellent technology, but in these units it can be a disaster because they are more prone to failure. Making matters worse, in the event of failure, data recovery can be much more difficult.
The takeaway here is that if you use external hard drives, be sure you only use a RAID device if you actually need it. In any event, if you are using one of these drives, you still need to have another backup. Of course, this is true with any data you value, but is easily overlooked here.
