To begin, I am NOT running a virtual server. There are no virtual servers anywhere in my environment.

I have my PDC, configured as a trusted time source. GPO points all servers and clients to the PDC for time. 

I have a 2008 R2 server (fully patched) that refuses to keep the PDC time. I run w32tm /resync and the time corrects itself. However a few seconds later the time reverts back to 5 minutes earlier (its previous out of sync time). No matter how many times I resync it goes back. It seems to do this right at the top of the minute.

w32tm /query /source shows my PDC as being the time source

This problem has been persistent for two days now (that i have notice and have been attempting to fix).

Thanks in advance

Hi,

I have seen this issue on laptops with buggy firmware.

Check the  MaxPosPhaseCorrection and MaxNegPhaseCorrection and maybe try to tune these values

https://support.microsoft.com/en-us/kb/884776

Took a look at those values on the server in question, they are the default values set by MS  which is 15 hours. Same for the Neg phase correction.

My time offset is ~ 5 min, so those values would seem to not have an impact.

Upon further reading, Windows does not make large time shifts when time is out of sync anyway, it simply speeds up the clock until time is in sync. However, that is not taking place in my situation as a 5 min correction would not take more than a hour to sync in that m

and that was the issue with the buggy firmware I was talking about.

My customer didn't want to update the firmware and I ended up scheduling a task which is running the following:

C:\Windows\System32\w32tm.exe /resync

I run it every 5 minutes.

You can check about your firmware.

Appreciate that work around, but would prefer to rectify root cause.

Running a Dell R310 server. Going to update the BIOS and see if that helps.

I have applied both the latest BIOS and Chipset downloads from Dell to my server. after a reboot, it is still behaving the same. 

w32tm /resync works and then time reverts back.

I'm afraid I can't be of further help. As you pointed out windows relay on the clock. W32time is designed to support kerberos:

"In short, W32time was created to assist computers to be equal to or less than five minutes (which is configurable) of each other for authentication purposes based off the Kerberos requirements. "

http://blogs.technet.com/b/askds/archive/2007/10/23/high-accuracy-w32time-requirements.aspx

All I can tell is that if 5 minutes are too much for your environment you might want to engage Dell.

Sorry about that.

Ale 

Its ok, i appreciate your time and effort in trying to help me.

I managed to solve the problem.

After considering all the different settings I have checked, it was clear to me that windows time was being set by some other source that was simply overriding w32time. So, with that in mind, I started hunting for any application that may be setting time. After finding no applications for time, I started looking at the running services, an low and behold there it was. FireDameon ( a program that can be used to automatically start any other program) was listed as FireDameon: Net time. 

sure enough, stopping that service and re-running w32tm /resync resulted in a persistent correct time.

starting that service resulted in the time reverting back.

I knew I had Fire Dameon installed, but was unaware that it was acting on system time (I fell in on my current server environment and others work on it as well). 

So, disable the service and problem solved. 

lesson for others, In a scenario where your time setup is correct and time just reverts back to some other time constantly after resync, consider what other applications may be trying to change system time. VM environments are subject to this conflict as well when your VM is taking its time from the VM manager.