Configuring a Subclient for Block-Level Backups for the Windows File System Agent

You can set up block-level backup operations to meet your requirements. By default, block-level backups are performed using the native snap engines. You can also use hardware snap engines to perform block-level backups. For more information about block-level backups, see Block-Level Backups.

You can configure a default subclient or create a new user-defined subclient to protect your file system data.

About this Task

Subclient filters are not supported for block-level backups. If you specify subclient filters, all files are backed up and the filters do not apply to the backups. If you select the Create File level Index during backup check box on the Advanced Options tab of the Subclient Properties dialog box you cannot view the filtered files during a browse operation. When you perform a volume-level restore, all files that meet the filter criteria are also restored.

Before You Begin

Before you begin, check whether you have completed the following tasks:

  1. Install the MediaAgent along with the File System Agent package on the client computer. For more information on the installations, see MediaAgent Installations and Preinstallation Checklist for the Windows File System Agent.

    Note: The VSS Provider package is installed as part of the MediaAgent installation. Make sure that you do not exclude the VSS Provider check box during the installation.

  2. Create a storage policy.

    Important: If selective copy is configured for the storage policy, you cannot select only incremental backup jobs to be copied to the storage policy during an Auxiliary Copy operation. For more information, see Manually Select a Job to Copy.

  3. When you run block-level backups using native or non-native snap engine, a snapshot copy is created with the Spool Copy (No Retention) option enabled automatically.

    Note: By default, block-level backup options are not available on upgraded clients. To enable block-level backups on upgraded clients, see Upgrade Considerations for the Windows File System Agent (V10 to V11) and Upgrade Considerations for the Windows File System Agent (V9 to V11).


  1. From the CommCell Browser, choose whether to configure the default subclient or to set up a user-defined subclient:
    • To configure the default subclient of the Windows File System Agent:
      1. Expand Client Computers > Client > File System > backup_set.
      2. Right-click the default subclient and then click Properties.
    • To set up a user-defined subclient of the Windows File System Agent:
      1. Expand Client Computers > Client > File System.
      2. Right-click the appropriate backup set, point to All Tasks, and then click New Subclient.
  2. On the General tab, in the Subclient box, type a name for the subclient.
  3. To set the content for the subclient, on the Content tab, click Browse to locate the content, and then click OK.


    • The subclient content must consist of a volume or a mount point. Do not add "/", system state, system drive, or any directory as the subclient content.
    • If you want to back up nested mounted points, you must list all the nested mount points separately in your subclient content. We recommend that if the parent mount point is defined in the user-defined subclient content then you must not list the nested mount points in the default subclient content.
    • You cannot enable OnePass for the subclient configured to perform block-level backups.
    • NFS and UNC paths are not supported.
  4. On the Storage Device tab, from the Storage Policy list, select an appropriate storage policy. For native snapshot engines, use a storage policy that does not have a snapshot copy configured on it or use a storage policy that has the snapshot copy configured with the spool retention enabled on it.
  5. Click Advanced.
  6. In the Advanced Subclient Properties dialog box, click the Advanced Options tab.
  7. On the Advanced Options tab, set up your block-level backup:
    1. To enable block-level backup, select the Optimized for File system with large number of small files (Block-Level Backup) check box.
    2. To install the block filter driver, select the Install block filter driver check box.


      • This operation is irreversible and you cannot uninstall block filter driver at a later time. All backups run as Full backups until you restart your computer.
      • The Install block filter driver check box is displayed for the first subclient you configure. Once you click OK, the option will not be displayed in any subclient residing under the client computers node.
    3. To perform file-level browse faster, select the Create File level Index during backup check box.

      Backups may take longer when you enable this option depending on the data scan type selected.

      Scan Type Effect
      Recursive Scan A file system scan is used to determine the modified data, resulting in a longer completion time.
      Optimized Scan A customized database that contains information about the files is used to quickly determine the modified data, resulting in a reduced scan time.
  8. Select additional options as appropriate for subclient creation and click OK.

    The new subclient appears under defaultBackupSet node.

Note: If you are performing block-level backup for LUNs exposed using a hardware snap engine, see Configuring a Subclient for Windows File System Agent Block-Level Backups Using SnapProtect.

What To Do Next

Perform block-level backups. For more information, see Performing Block-Level Backups for the Windows File System Agent.