Pruning Performance of Aged Deduplicated Jobs on a Disk is Slow

Article ID: DD0057 If you are experiencing pruning performance issues, you can troubleshoot them by performing the following basic operations.


Pruning performance of aged deduplicated job records on a disk is slow.


To improve the performance of the deduplication pruning, complete one of the following tasks.

  • Ensure that the DDB is hosted on a server with high-speed processor and effective memory that delivers good deduplication performance.

    Depending on your environment, relocate the DDB to a storage that meets the performance requirements associated with Deduplication operations. See Move the Deduplication Database for instructions.

    To ensure optimal performance for deduplication operations, the disk hosting the DDB must satisfy the specifications mentioned in Deduplication Building Block Guide.

  • Set the minimum reserve space on a mount path to 10% of the disk size. For example, if the disk size of the mount path is 100 GB, set the Reserve Space to 10 GB.

    See Establish Space Allocation on the Mount Path for instructions.

  • Enable Disk Write Cache on the disk that is hosting the disk library and the DDB.

    For instructions, refer the KB259716 Microsoft Knowledge Base article on

  • If the pruning is slow on the disk library hosted on the Windows MediaAgent due to low disk IO operations and throughput, install the Microsoft hot fixes KB982383 and KB2769701.

    For more information, refer the KB982383 and KB2769701 Microsoft Knowledge Base article on

  • Modify the Microsoft Multipath I/O settings based on the issues explained in the Updated Guidance on Microsoft MPIO Settings.
  • Verify the Windows System Event log for any errors referencing to the mount path containing the aged data.
  • Check if any antivirus security software is in process of scanning the CV_MAGNETIC folder on library mount paths. The Antivirus security software scan can prevent the pruning process.

    Therefore, exclude the CV_MAGNETIC folder from the antivirus security software scan.

  • Defragment the disk library volumes.

    See Fragmentation Analysis for instructions.

  • For UNIX or Linux MediaAgents, if disk library mount paths are using NFS share, ensure the following:

    • actimeo mount option value is set other than 0.

    • sync option is not set for the mount.