Redundant Array of Independent Disks
(RAID) A standard naming convention for various ways of using multiple disk drives to provide redundancy and distributed I/O.
The original ("..Inexpensive..") term referred to the 3.5 and 5.25 inch disks used for the first RAID system but no longer applies. As solid state drives are becoming a practical repacement for magnetic disks, "RAID" is sometimes expanded as "Redundant Array of Independent Drives".
The following standard RAID specifications exist:
RAID 0 Non-redundant striped array RAID 1 Mirrored arrays RAID 2 Parallel array with ECC RAID 3 Parallel array with parity RAID 4 Striped array with parity RAID 5 Striped array with rotating parity
RAID originated in a project at the computer science department of the University of California at Berkeley, under the direction of Professor Katz, in conjunction with Professor John Ousterhout and Professor David Patterson. A prototype disk array file server with a capacity of 40 GBytes and a sustained bandwidth of 80 MBytes/second was interfaced to a 1 Gb/s local area network. It was planned to extend the storage array to include automated optical disks and magnetic tapes.
["A Case for Redundant Arrays of Inexpensive Disks (RAID)", "D. A. Patterson and G. Gibson and R. H. Katz", Proc ACM SIGMOD Conf, Chicago, IL, Jun 1988].
["Introduction to Redundant Arrays of Inexpensive Disks (RAID)", "D. A. Patterson and P. Chen and G. Gibson and R. H. Katz", IEEE COMPCON 89, San Francisco, Feb-Mar 1989].