Configuring Additional Partitions for a Deduplication Database

You can add more partitions to an existing and online deduplication database (DDB) that is used by a storage policy enabled with deduplication. For example, you can change a single DDB configuration to a two-partitioned or a four-partitioned DDB configuration, or two-partitioned DDB configuration to a three-partitioned or a four-partitioned DDB.

After new partitions are added to a DDB, and on running backups, the signatures are distributed evenly across the partitions. New baseline for the DDB store is started each time a new partition is added and some of the same signatures might be written to the new partition even though they exist in the DDB store.

The data is aged when there are no more references to the blocks left and then the data is pruned physically from the DDB as well as from the magnetic disk.

For example: In your environment you have a DDB store and with Backup1 you back up 1 MB of data. This backup will create 8 signatures of 128 KB size each. The magnetic disk will have 1 MB of data.

After running the Backup1, you add Partition2 and run Backup2 of the same 1 MB of data. After the second backup, 4 signatures of 128 KB size will be added to Partition2 (even though the same signatures exists in the original store) and for the other 4 signatures only the reference will be added in the original store (as the signatures already exists). The magnetic disk will have 1.5 MB of data (1 MB from the first Backup + 500 KB from Partition2 from Backup2).

On running data aging, if Backup1 is aged, then from the first partition the first 4 signatures will be aged and also 500 KB of data will be pruned from the magnetic disk.

The following table presents the extra baseline created with addition of partitions.

Number of Existing Partitions	New Total Number of Partitions	Extra Baseline Created with the Addition (%) ([Total Partitions-Existing Partitions]/Total Partitions*100)
1	2	50
1	3	66
1	4	75
1	5	80
1	6	83
2	3	33
2	4	50
2	5	60
2	6	66

Support:

Adding additional partitions for deduplication database is supported for the following:

When you have upgraded your CommServe to v11 but the DDB is v10 on a v10 MediaAgent
When you have upgraded your CommServe to v11 but the DDB is v10 on a v11 MediaAgent
Where the DDB is v11 on a v11 MediaAgent

Exception: Changing a two-partitioned DDB configuration to a one-partitioned DDB, or a single DDB configuration to a three-partitioned DDB configuration is not allowed.

To define the maximum number of allowed DDB partitions, set the Maximum allowed substore configuration parameter to 6. For more information, see Media Management Configuration: Deduplication.

Before You Begin

Before configuring additional partitions the active DDB make sure that the destination MediaAgent is of same operating system type as of source MediaAgent.

For example, 64-bit to 64-bit or Windows to Windows MediaAgent.

Exception: You cannot configure the DDB from Windows to Linux or from Linux to Windows and Linux different bit versions (for example, 64-bit to 32-bit version).
When configuring additional partitions to the DDB, if any data protection job is running to the storage policy, then the data protection job will go to Pending state and resumes as per the Job Restart interval.

Procedure

From the CommCell Browser, expand Storage Resources > Deduplication Engines > storage_policy_copy.
Right-click the deduplication_database and then click Advanced > Add Partitions.
In the Configure Additional Partitions dialog box, in the MediaAgent And Partition Path column, click Choose Path to add the location of the appropriate partition.
In the Partition Path dialog box, specify the following:
1. From the MediaAgent list, select the MediaAgent that will be used to access the partition path.
2. In the Partition Path box, enter the file path where you want to locate the DDB.
3. Optional: Click the Advanced button and add the following information:
  1. DDB Network Interface: Define dedicated network interface name for each partition MediaAgent .
    Notes
    - By default, no data network interface(DIP) pair is configured. We recommend that you configure a dedicated Network Interface Card (NIC) on each partition MediaAgent and set up DIP between the data path and partition MediaAgents to increase the speed of the communication between the MediaAgents, improve data protection job throughput and 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.
    - 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.
    - If DIP is configured and the library setup with the DDB storage policy has the Automatically add data paths for new Drivepools configured, then on adding a new MediaAgent a DIP will automatically be configured.
  2. VSS COW Volume: Drive to host the snapshot created by the DDB backup process using VSS Copy-on-Write (COW) method.
    Notes
    - 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.
4. Click OK.
Click OK.

Result

The new partition appears under the DDB.