Synthetic Full Backup

Table of Contents

Verify Synthetic Full Backups

When producing a synthetic full backup, the SnapProtect software can determine what has changed (and which therefore needs to be backed up) in several ways. Selecting the Verify Synthetic Full option tells the synthetic full backup process to include the information currently in the index together with those other sources of change information. Doing this catches some unusual-case changes that might otherwise be missed, and the new or changed data is backed up as intended.

The illustration below describes this process in detail.

Produce a verified Synthetic Full backup as follows:

  1. From the CommCell Console, expand Client Computers > client > File System > defaultBackupSet.
  2. Right click the subclient, then click Backup.
  3. Select Synthetic Full, then click Advanced.
  4. On the Data tab, select Verify Synthetic Full.
  5. Click OK twice.

Starting a data protection operation on a backup set, instance or agent level causes the system to start individual data protection operations for each subclient contained therein. If the subclients are associated with the same storage policy, then their operations will run sequentially unless that storage policy is configured to accommodate multiple data streams.

Run Accelerated Synthetic Full Backup (DASH Full)

Accelerated Synthetic full backups, or DASH Full backups, are useful because:

  • Duration of data copy operation is small. This is due to the fact that data signatures get copied instead of the data itself.
  • Less space is consumed on the storage media as there is minimal data transfer.

Pre-requisites

  • Disk Library must be configured
  • Storage Policy must be created

You can setup DASH Full backups using the following steps:

  1. Enable DASH Full (Read Optimized Synthetic Full) in the Storage Policy Copy:
    1. From the CommCell Browser, navigate to Policies > Storage Policies > storage_policy.
    2. Right-click the primary storage policy copy displayed in the right pane, then click Properties.
    3. Click the Deduplication tab, then click the Advanced tab.
    4. Select the Enable DASH Full (Read Optimized Synthetic Full) check box, and then click OK.
  2. Associate Subclients to the Storage Policy Copy:
    1. From the CommCell Browser, navigate to Client Computers > client > File System > defaultBackupSet.
    2. Right-click the subclient in the right pane and click Properties.
    3. Click the Storage Device tab.
    4. In the Storage Policy list, click the storage policy where DASH full was enabled, and then click OK.
  3. Run a Full Backup.
  4. Run an Accelerated Synthetic Full Backup using the following steps:
    1. From the CommCell Browser, navigate to Client Computers > client > File System > defaultBackupSet.
    2. Right-click subclient > Backup.
    3. In the Backup Options dialog box, select Backup Type of Synthetic Full.

      By default, the Run Incremental Backup box and Before Synthetic Full option are selected.

    4. Click OK.
  5. You can track the progress of the job from the Job Controller window. Ensure that the job completes successfully.
    1. Right click the job, then click Details.
    2. Click the Progress tab.

      In the Progress tab, the Transferred Data Size on Network displays the amount of data sent over the network.

Limiting the Number of Concurrent Synthetic Full Jobs

You can limit the number of Synthetic Full jobs that can run concurrently by adding the JMSynthFullJobHighWaterMark Additional Setting to your CommServe host.

Here are the steps:

  1. From the CommCell Browser, right-click CommServe > Properties.
  2. Click the Additional Settings tab, then click Add.
  3. In Name, enter JMSynthFullJobHighWaterMark, then press TAB.

    The Category (CommServe) and Type (INTEGER) fields automatically populate.

  4. In Value, enter an integer between 1 and 200.
  5. Verify that Enable is selected, then click OK repeatedly until all dialogs are closed.