Despite the use of data replication to mirror systems, databases, and file stores, data backup remains an essential IT function by providing for long-term, archival storage of valuable information, much of which has legal and regulatory requirements regarding its preservation. Backups also can be used to store multiple versions of system images and data, allowing organizations to reverse changes, accidental deletions, or corrupted data quickly, restoring the system or database to a known good state.
Backup software can use different types of storage media depending on the likelihood of needing the data:
- external disks or virtual tape libraries for active data and tape
- optical disks or a cloud service for long-term storage
Backup systems routinely log activity and system conditions, recording information such as job history, error conditions, backup target and a detailed manifest of copied files or volumes. This data allows operations teams to monitor the health of backup systems, software and jobs; triggers alerts in the case of errors; and assists in debugging backup failures. It also allows teams to locate where specific data may be stored, when a recovery is required.