Virtual DCs and Time Sync

 

Microsoft has just changed their argument regarding disabling the time synch integration services when running VMs (including DCs) .

Time Sync via Integration services is important when time service is not running ,like when you boot the machine or restore it from snapshot or resume.

So what should be done is to allow Time sync via Integration Services when the time sync cannot function ( revert from snapshot or resume) ,and get control back to windows time sync when it can function

Microsoft said “The recommendation now is to partially disable time synchronization between the host system and guest operating system acting as a domain controller. This enables your guest domain controller to synchronize time for the domain hierarchy, but protects it from having a time skew if it is restored from a Saved state

To do this and partially disable Time Sync via Integration services, we must change this registry key to zero :

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\W32Time\TimeProviders\VMICTimeProvider\Enabled

“This command stops Windows Time service (W32Time) from using Hyper-V time synchronization integration when the guest domain controller’s operating system is started. With this setting disabled, the Hyper-V time synchronization provider is only used if the guest domain controller is rebooted or restored from a Saved state.”

Finally we got an officially answer about this topic. Furthermore, to know the authoritative time source for a machine , you can run this command w32tm /query /source

 

 

http://technet.microsoft.com/en-us/library/virtual_active_directory_domain_controller_virtualization_hyperv(WS.10).aspx

6 comments on “Virtual DCs and Time Sync

  1. I am curious to find out what blog platform you happen to be
    using? I’m experiencing some minor security problems with my latest site and I would like to find something more safeguarded. Do you have any suggestions?

  2. Having read this I believed it was very informative. I appreciate you spending some
    time and effort to put this article together. I once again
    find myself spending a lot of time both reading
    and posting comments. But so what, it was still worthwhile!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s