Disk array - a set of disks from one or more commonly accessible disk subsystems, combined with a body of control software.
The control software presents the disks' storage capacity to hosts as one or more virtual disks. Control software is often called firmware or microcode when it runs in a disk controller. Control software that runs in a host computer is usually called a volume manager.
Provides increased availability, resiliency, and maintainability by using existing components (controllers, power supplies, fans, etc.), often up to the point where all single points of failure (SPOFs) are eliminated from the design. Additionally, disk array components are often hot-swappable.
Typically, disk arrays are divided into categories:
- Network attached storage (NAS) arrays
- Storage area network (SAN) arrays:
- Modular SAN arrays
- Monolithic SAN arrays
- Utility Storage Arrays
- Storage virtualization
Primary vendors of storage systems include Coraid, Inc., DataDirect Networks, Dell, EMC Corporation, Hewlett-Packard, Hitachi Data Systems, IBM, Infortrend, NetApp, Oracle Corporation, Panasas and other companies that often act as OEMs for the above vendors and do not themselves market the storage components they manufacture.