RAID is an acronym that stands for Redundant Array of Independent Disks. It is a method of spreading information across several disks. Information can be duplicated on several disks, hence the word redundancy in the technique's name. By spreading stored data across several hard disks instead of one, users can get both faster performance and much greater data security. Depending upon the RAID system being used, a failed drive can be replaced without having to shut down the host system.

In 1987, a group at University of California, Berkley published a paper proposing a form of data storage they called RAID. The technology was designed to increase the speed of secondary memory, so as to keep pace with the increasing speed of central processing units.

There are several levels of RAID configurations. RAID 0 writes data across the different drives...