Creating User-Defined Subclients

Applies to: Exchange 2010 or later, and IntelliSnap

By default, all databases are assigned to the default subclient. However, you can divide databases across one or more user-defined subclients to make backups run more efficiently.

In a DAG environment, you select the Exchange server backup source to be a single server (manual selection) or the next available passive server (automatic selection).

Manual selection

For each database, configure backups to run on any one of the available DAG servers.

Manual server selection allows backups of Mailbox and Public Folder databases.

Automatic selection

Determine from which server the backup is run.

  • Because database-centric processes require a lot of resources, running a backup job on the active server might slow down other processes. By default, backups run on the first available passive server.
  • If there are no passive servers available, you can configure backups to run on the active server.
  • In addition, you can configure backups to run on the server with the highest number of activation preferences. This ensures the backup runs on a server that is least likely to become active in a failover case.

Automatic server selection allows backups of Mailbox and Public Folder databases.


  • By default, block-level backup is enabled for a newly-created user-defined subclient. To disable block-level backup, see Disabling Block-Level Backup for Exchange Databases.
  • You can change the method for selecting the backup source after you create the user-defined subclient in the Subclient Properties dialog box.


  1. From the CommCell Browser, expand Client Computers > client.
  2. Right-click Exchange Database, and then click All Tasks > New Subclient.

    The Subclient Properties dialog box appears.

  3. In the Subclient Name box, type a name.
  4. Click the Contents tab.
  5. Click Configure.

    The Add/Modify Subclients for Exchange Database dialog box appears.

  6. Click Discover.

    A list of databases appears.

  7. Choose whether to assign one or more databases to the subclient.
    • To assign one database to the new subclient, select a database in the Database Name column, and then select the new subclient name from the Subclient list.
    • To assign multiple databases to the new subclient, select all of the appropriate databases in the Database Name column, and then select the new subclient from the Change all selected storage groups to list.
  8. Click OK.
  9. If you use a DAG environment, click the Server Selection tab, and then configure the backup source.

    Option to configure the backup source


    Manual selection

    1. Select Manual selection, and then click Discover.

      All the discovered databases appear in the Server Associations list.

    2. Select the server where you want to back up the databases.

    Automatic selection

    1. Select Automatic selection.
    2. Select the Backup from passive copy check box.
    3. If there are no passive servers available, select the Backup from Active copy if no passive copy is available check box.
    4. Select the Use last activation preference to select passive copy check box.
  10. Click the Storage Device tab.
  11. On the Data Storage Policy subtab, from the Storage Policy list, select the appropriate storage policy.
  12. On the Advanced Options tab, clear the Optimize for message level recovery check box.
  13. If you use IntelliSnap, select an engine.
    1. Click the IntelliSnap Operations tab.
    2. Select the IntelliSnap check box.

      A message appears that tells you that the next backup will be a full backup.

    3. Click OK.
    4. From the Available Snap Engines list, select the engine that matches your snapshot type. For a list of available engines for your array, see Snapshot Engine.

      From the Use Proxy list, select the appropriate MediaAgent.

      This is the MediaAgent that is used to perform the IntelliSnap and backup copy operations.

      Note: When you perform an IntelliSnap backup using a proxy, make sure that the operating system on the proxy server is either same version or later than the operating system on the client computer.

    5. Optional: If you want to perform the backup copy operations on a different MediaAgent, select the Use Separate Proxy for Backup Copy check box, and then select the appropriate MediaAgent from the Proxy list.
  14. Click OK.


After a database is assigned to a user-defined subclient, it is removed from the default subclient.

Last modified: 10/8/2020 11:46:28 AM