Redundant array of independent disks

What is RAID (Redundant Arrays of independent disks)?

RAID, or “Redundant Arrays of Independent Disks” is a technique which makes use of a combination of multiple disks instead of using a single disk for increased performance, data redundancy or both. The term was coined by David Patterson, Garth A. Gibson, and Randy Katz at the University of California, Berkeley in 1987.

How much space is in a RAID array?

Each drive's storage space is divided into units ranging from a sector of 512 bytes up to several megabytes. The stripes of all the disks are interleaved and addressed in order. Disk mirroring and disk striping can also be combined in a RAID array. An image of a hard drive in a RAID array.

What is a disk array configuration?

A typical disk array configuration consists of small disk drives connected to a controller housing the software and coordinating the transfer of data in the disks to a large capacity disk connected to I/O subsystem. Note that this whole configuration is viewed as a single large-capacity disk by the OS.