The retention period for data depends on how likely the need is to restore information from media after a certain period of time. Some data (financial records, for example) have legal requirements that determine the retention level. Other data (preliminary documents, for example) can probably be expired when the final version is complete.

A backup's retention also depends on what needs to be recovered from the backup. For example, if day-to-day changes are critical, keep all the incremental backups in addition to the full backups for as long as the data is needed. If incremental backups only track work in progress toward monthly reports, expire the incremental backups sooner. Rely on the full backups for long-term recovery.

Establish some guidelines that apply to most of the data to determine retention periods. Note the files or the directories that have retention requirements outside of these guidelines. Plan to create separate policies for the data that falls outside of the retention requirement guidelines. For example, place the files and directories with longer retention requirements in a separate policy. Schedule longer retention times for the separate policies without keeping all policies for the longer retention period.

Another consideration for data retention is off-site storage of the backup media. Off-site storage protects against the disasters that occur at the primary site.

Ensure that adequate retention periods are configured, regardless of the method that is used for off-site storage. Use the NetBackup import feature to retrieve expired backups.