Precautions for assigning retention periods

For full backups, specify a time period that is longer than the frequency setting for the schedule. (The frequency is how often the backup runs). For example, if the frequency for a full backup is one week, specify a retention period of two to four weeks. Two to four weeks provides enough of a margin to ensure that the current full backup does not expire before the next full backup occurs.

For cumulative incremental backups, specify a time period that is longer than the frequency setting for the schedule. For example, if the frequency setting is one day, specify a retention period of one week. One week provides enough of a margin to ensure that the current cumulative-incremental backup does not expire before the next successful one occurs. A complete restore requires the previous full backup plus the most recent cumulative-incremental backup.

For differential incremental backups, specify a time period that is longer than the period between full backups. For example, if full backups occur weekly, save the incremental backups for two weeks.

A complete restore requires the previous full backup plus all subsequent incremental backups.

NetBackup does not track backups after the retention period expires. Assign an adequate retention period as recovering files after the retention period expires is difficult or impossible.
Within a policy, assign a longer retention period to full backups than to incremental backups. It may not be possible to restore all the files if the full backup expires before the incremental backups.
Archive schedules normally use an infinite retention period.