Beware of Double Drives
Consumers want high-capacity storage, and several companies are delivering--sort of. External hard drives with at least 1 terabyte of space appear to the user as a single drive volume, but they really combine multiple drives in one case. LaCie's 1TB d2 Big Disk comprises two 500GB drives. Iomega's 1TB XL Desktop Hard Drive contains four. The drives are configured as RAID 0, which spreads data across multiple drives to maximize data transfer speeds.
Who cares? You should. If one of the drives fails, you'll have little chance of recovering the data stored on the others. The solution: Schedule frequent backups or purchase an external drive that you can configure in a way (such as RAID 5) that allows you to rebuild your data. These drives tend to be more expensive, unfortunately.