 - In information technology, high availability refers to a system or component that is continuously operational for a desirably long length of time. availability can be measured relative to "100% operational" or "never failing." A widely-held but difficult-to-achieve standard of availability for a system or product is known as "five 9s" (99.999 percent) availability.
Since a computer system or a network consists of many parts in which all parts usually need to be present in order for the whole to be operational, much planning for high availability centers around backup and failover processing and data storage and access. For storage, a redundant array of independent disks (RAID) is one approach. A more recent approach is the storage area network (SAN).
Some availability experts emphasize that, for any system to be highly available, the parts of a system should be well-designed and thoroughly tested before they are used. For example, a new application program that has not been thoroughly tested is likely to become a frequent point-of-breakdown in a production system.
| LAST UPDATED: |
31 Jan 2005
|
 |
Read more about high availability:
|
|
Do you have something to add to this definition? Let us know.
Send your comments to techterms@whatis.com
|
 |
 |
| |
RELATED GLOSSARY TERMS
| Terms from Whatis.com − the technology online dictionary |
 |
Business Continuity and Disaster Recovery (BCDR)
(SearchStorage.com)
Business Continuity and Disaster Recovery (BCDR or BC/DR) are closely related practices that describe an organization's preparation for unforeseen...
|
|
RAIN
(SearchDataCenter.com)
RAIN (also called channel bonding, redundant array of independent nodes, reliable array of independent nodes, or random array of independent nodes)...
|
|
|
