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 parityRAID 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. ftp://wuarchive.wustl.edu/doc/techreports/berkeley.edu/raid/raidPapers. http://HTTP.CS.Berkeley.EDU/projects/parallel/research_summaries/14-Computer-Architecture/. ["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].
Last updated: 2012-08-26
Redundant Array of Independent DrivesRedundant Arrays of Independent Disks
Redundant Array of Inexpensive DisksRedundant Arrays of Independent Disks
Redundant Array of Inexpensive Servers
(RAIS) The use of multiple servers to provide the same service in such a way that service will still be available if one or more of the servers fails. The term may or may not imply some kind of load balancing between the servers. See cluster.The term "RAIS" follows RAID, which describes schemes for resilient disk storage.
Last updated: 2007-02-28