A synthetic full backup is a synthesized backup created from the most recent full backup and subsequent incremental and/or differential backup. The resulting synthetic full backup is identical to a full backup for the subclient.
Note
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The system will not run a synthetic full backup job if no incremental or differential backups were run after the last full or synthetic full backup.
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For file systems and VMs, the system will run an automatic synthetic full backup job only if all of the following conditions are true:
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The current application size is greater than or equal to 1 GB.
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The sum of the sizes of the backup jobs in the current cycle is greater than or equal to 1 GB.
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The sum of the sizes of the backup jobs in the current cycle is greater than the current application size by more than 75%.
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For more about synthetic full backups, see Synthetic Full Backups.
Unlike full, incremental, and differential backups, a synthetic full backup does not actually transfer data from a client computer to the backup media. Therefore, they do not use any resources on the client computer.
Synthetic full backups are media-based; they read backup data from one media and simultaneously write (restore) the result to the new active media within the same media group. As a result, synthetic full backups require that at least two media drives for the same storage policy be available at the time the job is started. Synthetic full backups cannot be performed on subclients where the storage policy is associated with a stand-alone drive.
Note
Run synthetic full backups every 365 days for media consolidation and to prune deleted items. This enhances the data restore speed.
Procedure
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From the CommCell Console, navigate to Policies > Schedule Policies.
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Right-click the laptop_schedule_policy and click Edit.
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Click Add.
The Backup Task Options dialog box appears.
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On the Backup Options tab, click Synthetic Full.
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Optional: To run an incremental backup before or after the synthetic full backup, select Run Incremental Backup, and then select one of the following:
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To run an incremental backup before the synthetic backup, select Before Synthetic Full.
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To run an incremental backup after the synthetic backup, select After Synthetic Full.
Note
The Run Incremental Backup option is not supported for automatic synthetic full schedules.
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On the Schedule Pattern tab, type a name in the Schedule Name box and click Automatic.
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On the Synthetic Full sub-tab, select one of the following options:
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Run Synthetic Full backups every X days. Defines the number of days that should pass between automatic synthetic full backups.
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Run Synthetic Full - As needed for extended retention. Defines the number of days that should pass between synthetic full backup jobs based on the storage policy’s extended retention rules defined by the user. If extended retention rules are not configured, then synthetic full backup jobs will run every 30 days.
Note
Even if extended retention rules are configured and set to retain full backups that are less than 30 days (for example, Hourly Full backups or Daily Full backups), the synthetic full backup jobs will not run more frequently than once every 30 days.
A storage policy’s extended retention rules may be defined in the following two settings in the CommCell Console:
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Extended Retention Rules for Full Backups (CommCell Console > Storage Policy > Storage Policy Copy > Properties > Retention)
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Automatically select Full Backups at frequency (CommCell Console > Storage Policy > Properties > Selective Copy)
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Run Synthetic Full - As needed to reclaim space. Automatically triggers a synthetic full backup job in order to reclaim space from backed up media.
Note
The Synthetic Full Backup sub-tab is available after Synthetic Full is selected from the Backup Options tab.
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Click OK.