A disk array is a disk storage system which contains multiple disk drives. It is differentiated from a disk enclosure, in that an array has cache memory and advanced functionality, like:
Components of a typical disk array include:
Typically a disk array provides increased availability, resiliency and maintainability by using additional, redundant components (controllers, power supplies, fans, etc.), often up to the point when all single points of failure (SPOFs) are eliminated from the design. Additionally those components are often hot-swappable.
Typically, disk arrays are divided into categories: