Redundant Array of Independent Disks (RAID) technology is a storage system using multiple disk drives to provide data redundancy needed for a highly secure system, with additional benefit of faster retrieval of data through multiple channel access. If one or a few disk drives fail, they can be normally exchanged without interruption of normal system operation. Thus, disk arrays can ensure that no data is lost if one disk drive in the array fails. The array includes drives, controllers, enclosure, power supplies, fans, cables, etc. and software. Each array is addressed by the host computer as one drive. There are several types of RAID configuration, called levels, which control the ways of organizing data on the drives and organizing the flow of data to and from the host computer.
