Redundant Array of Inexpensive Disks (RAID): Technology Description, Characterizations, Comparisons, Usage and Cost Benefits

Vish JUMANI
1994 Journal of the Magnetics Society of Japan  
Customer requirements have guided the evolution and implementation of software and hardware computer data storage technologies. The concept of RAID originated with a group of researchers "at the University of California at Be¥keley (UCB). They were investigating the use of an array of small capacity, inexpensive personal computer direct access storage devices (DASD) managed by a special type of a controller. as an alternative to the single large expensive disk (SLED) subsystems more common on
more » ... inframe computers. The disk arrays can be configured differently to provide different levels of operational capabilities, each providing special advantages in reliability and data availability, speed and economy. Different configurations are referred to as different levels of RAID. Berkeley originally defmed a basic set of RAID levels ranging from RAID, level 0 (RAID 0) through RAID,level5 (RAID 5). The RAID technology vendors have since extended the RAID level domain by defming RAID 6 and beyond to accommodate additional functionality. Each RAID type has shown itself to be suitable for certain applications. The projected reduction in storage costs and facilities, $/GB and ft2JGB respectively, using the present RAID technology and its projected evolution are phenomenal.
doi:10.3379/jmsjmag.18.s1_53 fatcat:u3ngsyjkrjebpkou7rslweilqu