To diagnose problems with Storage DRS, you can clear Storage DRS statistics before you manually run Storage DRS.

Important: When you enable the option to clear Storage DRS statistics, statistics are cleared every time Storage DRS runs until you disable the option. Always disable the option after you diagnose the Storage DRS problem.


Launch the vSphere Client and log in to a vCenter Server system.

Enable Storage DRS for the datastore cluster.


  1. Enable the ClearIoStatsOnSdrsRun option.
    1. In the vSphere Client, right-click the datastore cluster and select Edit Settings.
    2. Select SDRS Automation Level and click Advanced Options.
    3. In the Option text box, type ClearIoStatsOnSdrsRun.
    4. In the corresponding Value text box, type 1.
    5. Click OK, then click OK again to dismiss the settings dialog box.
  2. In the vSphere Client inventory, select a datastore cluster.
  3. Click the Storage DRS tab and select Run DRS in the upper right corner of the page.
    The current Storage DRS statistics for all datastores and virtual disks in all datastore clusters in the vSphere Client inventory are cleared, but no new statistics are collected.
  4. Change the ClearIoStatsOnSdrsRun flag value to 0 to disable it.
  5. Run Storage DRS again.
    Storage DRS runs normally. Allow several hours for the new setting to take effect.