In computers, backup storage is storage that is intended as a copy of the storage that is actively in use so that, if the storage medium such as a hard disk fails and data is lost on that medium, it can be recovered from the copy. In an enterprise, because the loss of business data can be catastrophic, it is important that backup storage be provided.
On a personal computer, backup storage is commonly achieved with Zip drives and DVDs. In an enterprise, backup storage can sometimes be achieved through replication of data in multidisk storage systems, such as RAID; as part of network-attached storage (NAS); as part of a storage area network (SAN); or as part of a tiered storage system. Enterprise backup storage often makes use of both disk and tape as storage media. Special software is used to manage backup as part of a storage system.
The same means and media used for backup storage are often used for archival storage.