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Disabling Time Synchronization (1189)


In the VMware Tools control panel, the time synchronization checkbox is unselected, but you may experience these symptoms:
  • When you suspend a virtual machine, the next time you resume that virtual machine it synchronizes the time to adjust it to the host.
  • Time is resynchronized when you migrate the virtual machine using vMotion, take a snapshot, restore to a snapshot, shrink the virtual disk, or restart the VMware Tools service in the virtual machine (including rebooting the virtual machine).


The time synchronization checkbox controls only whether time is periodically resynchronized while the virtual machine is running. Even if this box is unselected, by default VMware Tools synchronizes the virtual machine's time after a few specific events that are likely to leave the time incorrect.

There are two methods to completely disable time synchronization in the guest. Perform one of these procedures:

Note: Unlike the normal periodic time sync, which can move the guest clock only forward, these special time syncs can move the guest clock either forward or backward. If you want your guests to never sync backward in time, disable the options (by selecting "0" for each option).

  • Add configuration options in the virtual machine's .vmx file:

    1. Open the virtual machine's configuration file (/vmfs/volumes/datastore_name/vm_name/vm_name.vmx) using a text editor.
    2. Set these options to zero. If the entries do not exist, add them.

      Note: 0 = disabled, 1 = enabled.

      tools.syncTime = "0"
      time.synchronize.continue = "0"
      time.synchronize.restore = "0"
      time.synchronize.resume.disk = "0"
      time.synchronize.shrink = "0" = "0" = "0" = "0"

      Note: In GSX, VMware Fusion, VMware Player and VMware Workstation, you must use "FALSE" instead of "0". For example:

      tools.syncTime = "FALSE"
      time.synchronize.continue = "FALSE"
      time.synchronize.restore = "FALSE"
      time.synchronize.resume.disk = "FALSE"
      time.synchronize.shrink = "FALSE" = "FALSE" = "FALSE" = "FALSE"

  • Add configuration parameters using the vSphere Client:

    1. Select the virtual machine in the vSphere Client inventory and power it off.
    2. On the Summary tab, click Edit Settings.
    3. Click the Options tab and click General (under Advanced).
    4. Click Configuration Parameters, then click Add Row and add this information:


    Note: When adding tools.syncTime via the Configuration Parameters in vSphere 5.x, it will not be displayed again after the entry has been accepted and closed. When you view the vm_name.vmx file, you see the parameter inserted as tools.syncTime = "FALSE".

This Article Replaces


Update History

04/20/2012 - Added = "0" and added note about disbling backward time sync 06/17/2011 - Added = "0" as an options 06/18/2013 - Added note on how to set the options in VMware Fusion/Workstation 03/03/2014- Added VMware Player to Note about using Flase for setting options

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