GRRRR AD Time

mdubya · 2014-12-19T18:03:33.000Z

6 months ago i thought I figured our time sync issues once and for all by specifying a external NTP server. Here I am again though with my time out of sync and I can’t get it to resync.

I saw somewhere that you can reset w32tm with:

net stop w32time
w32tm /unregister
w32tm /register
net start w32time

I then did this to reset time settings:

net stop w32time
w32tm /config /syncfromflags:manual /manualpeerlist:”0.pool.ntp.org, 1.pool.ntp.org, 2.pool.ntp.org”
w32tm /config /reliable:yes
net start w32time

I then run w32tm /resync and the time gets fixed. However, a split second later it changes back to the incorrect time. Where is it getting its time from?!? I did a netdom /query fsmo to make sure i’m working on the PDC and I am.

john3504 · 2014-12-19T18:08:00.000Z

It may be pulling the time from the machine bios.

rockn · 2014-12-19T18:09:21.000Z

What time does it revert to and where are you issuing the w32tm command at? Sorry. should have read that closer.

mdubya · 2014-12-19T18:15:45.000Z

These are Hyper-V vm’s, i’ve heard there can be sync issues with this. It’s pulling a time thats ~3 minutes in the future.

I dont understand why it would still pull a local system time when i’ve specified /syncfromflags:manual. Isn’t the point of specifying external servers so that it stops using local system time?

rockn · 2014-12-19T18:23:07.000Z

Take a look at this. Apparently the host is to be set up to sync from a NTP source and the VMs should use the time sync provider from the host if I am reading this correctly.

http://blogs.msdn.com/b/virtual_pc_guy/archive/2010/11/19/time-synchronization-in-hyper-v.aspx

overdrive · 2014-12-19T18:55:23.000Z

If your DC’s are VM’s, DO NOT sync the time using the VM utilities (in Microsoft’s Hyper-V, uncheck “Time Services” under Integration Services on the Settings of the VM.

Then use this command to set the time on the DC’s

w32tm /config /manualpeerlist:0.ca.pool.ntp.org,1.ca.pool.ntp.org,2.ca.pool.ntp.org,3.ca.pool.ntp.org /syncfromflags:manual /reliable:yes /update

You can also set up the DC’s to sync from the peer list through GPO as well.

System/Windows Time Service/Time Providers >
NtpServer 0.ca.pool.ntp.org 1.ca.pool.ntp.org 2.ca.pool.ntp.org 3.ca.pool.ntp.org 
Type NTP 
CrossSiteSyncFlags 2 
ResolvePeerBackoffMinutes 15 
ResolvePeerBackoffMaxTimes 7 
SpecialPollInterval 3600 
EventLogFlags 3 
 
Policy Setting Comment 
Enable Windows NTP Client Enabled

mhunt · 2014-12-19T19:30:33.000Z

I used:

(Powershell)

w32tm /config /manualpeerlist:pool.ntp.org /syncfromflags:MANUAL

Stop-Service w32time

Start-Service w32time

From here

rockn · 2014-12-19T20:13:32.000Z

Have you seen this?

http://community.spiceworks.com/topic/477104-do-you-disable-the-time-syncronization-service-in-hyper-v

james-for-microsoft · 2014-12-19T21:53:42.000Z

Double check your time sources in your registry:

http://community.spiceworks.com/how_to/show/86634-setting-up-and-managing-ntp

johnhartsell2203 · 2014-12-20T04:15:56.000Z

What happens when you run this:

w32tm /query /configuration

Type should be NTP.

When you run:

w32tm /query /source

That should show you where your system is configured to get NTP from.

Run the above from an Admin prompt.

mdubya · 2015-01-05T13:15:04.000Z

Severely delayed response, two week Christmas break

It looks like it was indeed an issue with it using the Hyper-V time sync in place of the NTP source. A lot of technet articles seem to indicate that best practice is to use a “partial sync”. Where for normal functioning it uses the w32tm source then for saved state, etc it’ll use the Hyper-V configuration. In multiple places i’ve seen to add this registry key to make this happen:

reg add HKLM\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\VMICTimeProvider /v Enabled /t reg_dword /d 0

Sources:

http://blogs.msdn.com/b/virtual_pc_guy/archive/2010/11/19/time-synchronization-in-hyper-v.aspx

learn.microsoft.com

Time Services for a Domain Controller on Hyper-V

This registry key %uFEFFdoes not%uFEFF work for me. It will still sync from the Hyper-V host unless I disable Time Sync on the VM itself. I have verified that w32tm is set to use the external NTP servers. But it looks like if I have time sync enabled on the VM it will override whatever setting is in w32tm. I know its not 100% best practice but i’m going to just leave Time sync disabled on the DC. I can’t spend too much more time fighting with this at the moment.

mdubya · 2015-03-11T13:39:57.000Z

This problem seems to persist, IDK what the problem is but this is frustrating. Something so seemingly simple. I have three DCs:

DC1 (Hyper-V no time sync) -

w32tm /query /configuration TYPE: NTP
W32tm /query /source: 0.pool.ntp.org,1.pool.ntp.org,2.pool.ntp.org

DC2 (Hyper-V no time sync) -

w32tm /query /configuration TYPE: NT5DS
W32tm /query /source: DC1

DC3 (VMware - no Timesync) -

w32tm /query /configuration TYPE: NT5DS
W32tm /query /source: DC1

If i run w32 /resync on DC1 the time is fixed. But later goes out of sync again. What am i missing?

overdrive · 2015-03-11T13:44:07.000Z

Why don’t you set them all to NTP?

rockn · 2015-03-11T13:47:38.000Z

The PDC emulator is the only one you should have to set the NTP pool information up on and the others should get their time from him/her.

mdubya · 2015-03-12T11:27:56.000Z

I did a w32tm /resync on the PDC and the time held for I believe the rest of the work day. This morning its off by 3 minutes again. Resync fixes it.

This machine is Hyper-V time sync is disabled, is it just losing that much time inbetween resyncs or not resyncing for some reason? Do I need to just check the sync interval, or make a scheduled task?