RAID (Redundant Array of Inexpensive Disks) is a means by which data is distributed over two or more physical hard drives to improve performance and increase data safety. A RAID can survive the loss of any one drive without losing data. RAID was formerly a SCSI technology and was generally limited by cost to use on servers and professional workstations. That changed a few years ago when Promise Technology (http://www.promise.com) introduced a line of ATA-based RAID controllers that combine the benefits of RAID with the low cost of ATA, making RAID a realistic alternative for small servers and individual PCs.
ATA drives are so inexpensive that RAID is increasingly popular for protecting data on desktop systems. Do note, though, that using RAID isn’t a substitute for backing up. RAID protects against drive failures, but does nothing to protect you against corrupted or accidentally deleted files. Never count on RAID to protect you against anything but drive failures.
For several years, we’ve used Promise ATA RAID cards on a couple of our servers and desktop systems. If you’re building a small server, or even if you just want to protect the data on your PC, look into ATA RAID products. Many manufacturers now produce ATA RAID cards, and some premium motherboards include embedded ATA RAID support.
There are five defined levels of RAID, numbered RAID 1 through RAID 5, although not all of those levels are appropriate for PC environments. Some or all of the following ...