V11 SP8

Creating a Storage Policy with Deduplication

Create a storage policy with deduplication as an efficient method to store data that identifies and eliminates duplicate blocks of data during backups.

You can create a storage policy by using the Create a Storage Policy wizard.

Alternatively, you can automate storage policy creation with deduplication by using configuration XML. For more information, see Creating Deduplication Enabled Storage Policy.


  1. In the CommCell Browser, expand Policies.
  2. Right-click the Storage Policy, and then click New Storage Policy.

    The Create Storage Policy Wizard opens.

    Refer to the following sections during the storage policy creation.

    Expand All

    Storage Policy Type

    Data Protection and Archiving

    Storage Policy Name

    Name of the storage policy.

    For example: SP_for_VMWareBackups.

    Use Existing Global Deduplication Policy

    Yes or No.

    Library details

    Name of the disk library.

    The initial library for the storage policy. You can add more libraries as a data path after the storage policy is configured.

    MediaAgent details

    Name of the MediaAgent that has access to the library. You can add more MediaAgents after the storage policy is configured.

    Device Stream and Retention Rules

    The number of device streams to use during backup or restore operations for all the subclients that will use this storage policy.

    Important: The number of device streams must be equal to or less than the maximum number of writers allowed to the disk libraries used by this storage policy copy.

    To view or modify the values for writers on the disk library, see Establish the Mount Path Allocation Policy for the Library.

    By default, the data retention for backup jobs is set to 15 days and two cycles. For archive jobs, it is set to infinite.

    You can accept the defaults now and then modify the retention rules to change the retention period after the storage policy is created. To modify the retention rules after storage policy creation, see Setting Up Basic Retention Rules.

    If the Erase Data license is activated, you can select Allow Erase Data. When selected, you can erase data when the stubs are deleted from a specified drive, folder, or UNC path.

    Data Encryption

    Data encryption on the storage policy copies including the primary copy.

    When the Always enable encryption on new copies option is enabled in Media Management Configuration: Service Configuration tab, software encryption (using Blowfish with Key Length 128) is enabled in the primary copy, even if the encryption setting is not selected explicitly during the storage policy creation process.

    You can enable the Software Encryption (using Blowfish with Key Length 128) now and modify the encryption settings from the Copy Properties - Advanced tab after the storage policy is created.

    Deduplication Modes

    Default: source-side on primary copy.

    You can accept the defaults or you can configure the Partitioned Deduplication Database (DDB) to host the DDB on multiple MediaAgents. For more information on Partitioned DDB, see Deduplication Database.

    Note: You can enable deduplication only during the storage policy creation.

    Location to host the Deduplication Database

    • DDB Location: The MediaAgent and location to host the DDB.
      • Before hosting the DDB, ensure that the MediaAgent and disk meets the hardware and software requirements referenced in Deduplication Building Block Guide.
      • Single or partitioned DDB configuration:
        • Place the DDB in a folder on a different volume or partition than that of the root file system.
        • Do not host the DDB under the software installation directory, for example software_installation_directory\Base directory.
        • For Linux, host the DDB on LVM volumes. The DDB Backups use LVM software for snapshots.
      • Partitioned DDB configuration:
        • Host each DDB on different physical drives for better performance.
        • When hosting the DDB on different MediaAgents, ensure that all MediaAgents are of similar operating system type with 64-bit version, and the MediaAgents are online.

          For more information on supported platforms, see Deduplication Building Block Guide.

        • For DDB Network Interface - By default, no data network interface pair is configured.

          We recommend that you configure a dedicated Network Interface Card (NIC) on each partition MediaAgent and set up data interface pair (DIP) between the data path and partition MediaAgents:

          • To increase the speed of the communication between the MediaAgents
          • To improve data protection job throughput
          • To avoid network bottlenecks

          If you have a NIC configured on a partition MediaAgent, specify the network interface name or IP address for the DDB Network Interface.


          • Push the firewall configuration on the DDB MediaAgent after adding a data interface pair and creating a storage policy copy. For more information, see Data Interface Pairs - Overview.
          • If DIP is configured between two MediaAgents and if no interface pair is specified during storage policy creation, the existing DIP is used between two MediaAgents.
          • Configuring DIP when the data path MediaAgent and the partition MediaAgent are same will resolve to the loopback IP( However, if you do configure DIP in such configuration where the data path MediaAgent and the partition MediaAgent are same, the DDB storage policy and storage policy copy properties will display the DDB Network Interface as Default.
          • No more than one DIP should be created between two clients. If another interface is created, the clients will use only the newer defined interface pair.
      • Disk configuration for the DDB LUN:
        • Format the Disk LUN that will host the DDB to a block size of 4 KB.
        • Configure LUNs so that no more than one DDB is configured on any one RAID group.
        • Configure only two DDBs per MediaAgent with two different LUN groups.
    • VSS COW volume: VSS Copy-on-Write (COW) volume is the location that hosts the snapshot of the drive where the DDB is hosted.

      By default, during DDB backups, the snapshot of the DDB drive is created by the using VSS COW method in the system default location. That is, the snapshot is stored in the DDB location.

      You can change the location that hosts the snapshot to a different location or drive for better performance on the DDB.


      • The VSS COW volume box is available only when no DDB subclient exists on a selected DDB MediaAgent and for version 11 MediaAgents.
      • If you changed the Windows shadow copy storage association to a different drive, the snapshot created during DDB backup is stored on that drive.
      • If you want to change the VSS COW volume location after storage policy creation, you can modify it on the DDB subclient. For more information, see Modifying the Properties of the Deduplication Database Subclient.
  3. Click Finish to create the storage policy.

    The new storage policy appears under the Storage Policies node.

What to Do Next

Associate a storage policy with a subclient and perform client backups.

For more information on how to run backups, see the documentation for the specific agent.