Testing IOPS of Deduplication Database Disk on Windows

Use the IOmeter to measure Input Output Operations Per Second (IOPS) for deduplication database disk I/O performance.

An IOPS rating provides a standard and simplified way to commission storage without having to understand and use proprietary tools.

Before You Begin

Consider the following guidelines before running the IOPS test with IOmeter:

  • You can run the IOmeter test for a space x+500 GB.

    Where x is the amount of front end cache for the array storage.

  • Ensure that you run the IOmeter test on the complete raw disk.
    • If you have a GPT (GUID Partition Table) disk, convert the GPT disk to a MBR (Master Boot Record) disk before running the IOmeter test. Refer to Microsoft documentation for details.
  • We recommend that you run IOmeter on the physical disk that represents the storage volume for which IOPS need to be measured. IOmeter allows physical disks to be selected only when there are no volumes on the disk.


  1. Log on to the MediaAgent computer where you want to test the storage disks or volume.
  2. Stop all MediaAgent services. For instructions, see Stopping a Service.
  3. Ensure that there is no SIDB.exe process running on the MediaAgent.
    • For Windows, verify from the Windows Task Manager - Processes tab.
  4. Running the IOmeter, depends on the following:
    • If there is 500 GB or more than half the size of DDB volume as free space, then skip to step 6.
    • If the free space is less than 500 GB, then move the DDB as described in Move the Deduplication Database.
  5. Go to the software_installation_directory/Base folder, right-click IOmeter, and then click Run as Administrator.
  6. In the license dialog box, click I Agree.
  7. In the Topology pane, expand All Manager > MediaAgent, delete all worker threads except one by selecting the worker thread and clicking the Disconnect Selected Worker or Manager icon.
  8. On the Disk Targets tab, select the appropriate options:
    1. Select the physical drives that host the DDBs ().
      • represents physical drives that have no partitions on them.
      • represents drives that need to be prepared before the test. These are the volumes that do not contain the iobw.tst file.

        Before running a test on a volume, IOmeter must prepare the volume. It creates a file named iobw.tst as part of this preparation phase and runs read/write tests on this file.

      • represents the logical (mounted) drives that are prepared and contain the iobw.tst file.
    2. In the Maximum Disk Size and Starting Disk Sector boxes, set the default value to 0.
  9. On the Access Specifications tab, in the Global Access Specifications box, create the IOmeter profile for the IOPS measurement test:
    1. Double-click Default.
    2. In the Edit Access Specification dialog box, change the following:
      • The Transfer Request Size to 4K Block Size
      • The Percent Read/Write Distribution to 50% reads and 50% writes
      • The Percent Random/Sequential Distribution to 100% random.
    3. Click OK.
    4. Click Add.

    The recommendedaccess specificationprofile closely emulates the way a disk is accessed by C-tree database lookups.

  10. To run IOPS with multiple worker threads, from the IOmeter toolbar, click Start a Duplicate of This Worker on This Managerto create a duplicate worker thread with the same settings.

    Repeat this step to create a total of 8 worker threads.

  11. On the Results Display tab, set the Update Frequency to 5 seconds.
  12. On the Test Setup tab, under Run Time, in the Minutes box, enter 30.
  13. From the IOmeter toolbar, click Start Teststo start the test.
    • The process of preparing the drive might take some time.
    • During the preparation, a iobw.tst file is created that purposely fills the drive and therefore any drive capacity related alert must be ignored.
  14. In the Save Results dialog box, select a file to store the test results, and click Save.

    After a few seconds the test result appears on the Results Display tab.

  15. Run the test for approximately 30 minutes or until the IOPS value has stabilized.
  16. Click Stop Current Test and Save Results.

    The test stops and the final results are saved in the results.csv file. Record the IOPS test rating.

  17. Recreate the volume on the disk with the same drive letter or mount path.

    If required, format the volume.

  18. If the DDB was moved to another location, then move it back to the volume. Move the Deduplication Database.
  19. Start all services.

    For instructions, see Starting a Service.


The minimum IOPS required for DDB disk for extra large, large and medium MediaAgent is:


Extra Large



Suggested IOPS for DDB Disk

20K dedicated Random IOPS

15K dedicated Random IOPS

5K dedicated Random IOPS

For more details, see Hardware Specifications for MediaAgent.

Last modified: 9/11/2019 6:05:39 PM