DC Time Issue

[techie08]

Hi Everyone

 

On one of my DC's im getting an event log warnings around 19:30 every evening saying "The time service has stopped advertising as a time source because the local clock is not synchronized." followed by:

 

"The time service detected a time difference of greater than 5000 milliseconds for 900 seconds. The time difference might be caused by synchronization with low-accuracy time sources or by suboptimal network conditions. The time service is no longer synchronized and cannot provide the time to other clients or update the system clock. When a valid time stamp is received from a time service provider, the time service will correct itself"

 

Its only happening on DC02 as DC1 and DC3 are ok.

 

Has anyone come accross this before? DCs 2 and 3 are VMs so not sure if this is part of the problem.

 

Many Thanks

[glennda]

try running Net time /set and then see if it still does it after a while.

 

Physical or Virtual??

[Michael]

In Windows domains, there cannot be more than 5 minutes difference between all servers and between a server and a workstation.

 

If the time is more than 5 mins out, it can create replication problems as well as the unavailability of services. Ideally your primary server (typically the FSMO holder) should sync to a reliable time source (externally), then your other servers and workstations should sync with your primary server.

 

This is what you should run on 2008 R2 from an elevated command prompt:

 

@echo off

net stop w32time

w32tm /config /syncfromflags:manual /manualpeerlist:ntp.bgfl.org

w32tm /config /reliable:yes

net start w32time

w32tm /query /peers

PAUSE

[Michael]

If the problems continue (despite using a reliable time source), I'd recommend changing the battery on the motherboard.

[techie08]

Glenda, DC2 is virtual where the problem is occuring. DC1 is Physical

 

Michael, should i run the command on the problem DC?

[glennda]

Run the commands on the physical DC and then the virtual dc's should sync to them - use Net time /set on the virtual one.

 

What virtulisation platform are you using?

[Michael]

It's safe to run it on all DCs, but typically you'd run it on your FSMO role holder.

 

I forgot to mention, change the NTP.BGFL.ORG bit to an alternative time source. That time server's only for Birmingham schools. Use POOL.NTP.ORG for example.

[techie08]

Run the commands on the physical DC and then the virtual dc's should sync to them - use Net time /set on the virtual one.

 

What virtulisation platform are you using?

 

VMware

 

Ive ran the command on DC2 so i will check tomorrow to see if it throws up any more warnings. DC1 was already syncing with ntp.swgfl.org.uk

Edited May 1, 2012 by techie08

[techie08]

Ive now noticed that im Getting the follow Kernel Gerneral logs saying:

 

The system time has changed to ‎2012‎-‎05‎-‎01T19:37:40.646000000Z from ‎2012‎-‎05‎-‎01T19:37:40.646062500Z.

 

The time is an hour behind!!!!

[Michael]

Check the Time Zone is correct, or as I said above, it could well be the onboard battery powering the BIOS chip.

[glennda]

Vmware and dcs for time are a bit dodgy - in Vmware you need to set the host to point to the same online ntp server as the dc