Type of Backup

Full or user

Snaps the volumes that contain the Exchange database, system, and log files.

Differential or cumulative incremental

Snaps the volumes that contain the Exchange system and log files. Differential backups require that the transaction logs are backed up to a storage unit and kept on the Instant Recovery snapshot volume. (Select the Snapshots and copy snapshots to a storage unit option.)

This configuration is required because all of the differential backups after the last full backup are required to fully restore a database. Since a differential backup truncates the transaction logs, there is no way to guarantee that all of the log files exist. Also, snapshot rotation might have snapped back or deleted one or more snapshot images. They must be backed up to a storage unit.

Instant Recovery

Snapshots and copy snapshots to a storage unit

NetBackup creates a disk snapshot and backs up the client's data to the storage unit that is specified for the policy. This option is required if you want to perform Instant Recovery backups with Granular Recovery Technology (GRT).

Transaction logs are deleted when the backup (full or differential) to the storage unit has completed.

Snapshots only

The image is not backed up to tape or to other storage. NetBackup creates a persistent snapshot only. Note that this persistent snapshot is not considered a replacement for traditional backup.

Transaction logs are not deleted for this schedule option. To delete transaction logs, you must perform a backup to a storage unit. Alternatively, you can configure NetBackup to delete logs for any full Instant Recovery backups that are snapshot only.

Retention

One week - infinity

The retention level indicates the maximum time that the Instant Recovery snapshot is retained. For full backups, select a retention level that ensures a full backup is always available for restore. The snapshot can be deleted before that time if the snapshot volume is required for another backup attempt.