A disk array is an enterprise storage system which contains multiple disk drives. It is differentiated from a disk enclosure in that an array has cache and intelligence so can perform functions like RAID and virtualization.

Components of a typical disk array include:

• Disk array controller
• Cache
• Disk enclosures
• Power supply

Typical disk arrays fall into three categories:

• Network attached storage (NAS) arrays:
  • Network Appliance Filer
• Modular storage area network (SAN) arrays:
  • EMC CLARiiON
  • HDS Thunder
• Monolithic storage area network (SAN) arrays:
  • EMC Symmetrix
  • HP XP