Leveraging disk as the primary backup destination allows concurrent backups and restores at the speed of disk. You can reduce your backup window by leveraging disk, stage data to disk and then to tape for concurrent fast backups, or create a duplicate set of tapes for offsite storage. Disk-to-disk-to-tape operations can automate these procedures with a great deal of flexibility. This TechTip describes how to use templates in Symantec Backup Exec to execute three types of disk-to-disk-to-tape operations.
Basic disk-to-disk-to-tape configuration
If you want to perform a backup to disk and then copy that backup to tape, use a direct link between the backup template and a duplicate template. In a direct disk-to-disk-to-tape operation, a backup template must be modified to call a Duplicate Backup Set Template once the first template completes. The template rule is: After <First Template> completes, start <Second Template> to duplicate the backup set. To create this job, go to Job Setup then New Policy in Backup Exec. In the first Backup Template, indicate the target location (disk) for the backup data. Set the schedule for the template; the Job Schedule should read Run according to schedule. Next, create a Duplicate Backup Sets Template (the second template) and indicate the disk source (the initial backup target from First Template) and the tape target. Apply the Run only according to rules for this template schedule option. The job will complete the scheduled backup to the target disk then copy the completed disk backup to tape.
Delayed tape copying outside the backup window
You may want to delay copying disk backups to tape. Using this option, you can schedule tape copies to occur outside the regular backup window, thereby reducing impact on network, server, and disk systems during the regular backup. To re-schedule tape copying, remove the Run only according to rules of this template in the Duplicate Backup Sets Template and specify the scheduled time when copy-to-tape operations should begin. The regular disk-to-disk backup operations will perform as previously scheduled, and the tape copying will begin at the time you specified.
Creating duplicate tape sets
If multiple operations are needed for creating tapes, incremental duplication methods should be used. For example, you may need to create a complete duplicate set of tapes for offsite storage and archiving after the first set of tapes have been created. To accomplish this, add a second Duplicate Backup Sets Template to the above configuration. Apply the template rule Duplicate all backup sets that were created by <First Template> using <Second Template> as scheduled. Backup Exec will create the disk-to-disk backup, copy this data to the first set of tapes according to its schedule, and then execute the second set of tape copies immediately afterwards.
Staging data for archiving to tape
This incremental operation is also useful for staging data for tape archiving or for moving only selected backup jobs at specific times to tape. For example, you might want to perform a full backup of data to a selected disk. After 28 days, you want to copy that data to another disk where it will remain for three months. Finally, you want to move the data from the three-month disk to a tape for permanent archiving. Configure the job as above, performing a backup to the target disk using a backup template. The second template (a Duplicate Backup Sets Template) performs another disk-to-disk backup every 28 days from the target disk location according to its 28-day schedule to the 3-month target disk. Finally, the third template (a Duplicate Backup Sets Template) schedules a copy of the data to tape every three months.
Whether copying data immediately from disk backups to tape or implementing a sophisticated data retention and tape archiving scheme, Backup Exec templates and policy rules can automate the entire process.
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