[Solved] Serious timesync issue

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[Solved] Serious timesync issue

Postby puithove » 6. Aug 2009, 23:34

I'm a VMWare veteran - have been using VMWare and other VM software for many years. I've always disabled any time sync service in the guest OS and let the VM vendor's services installed in the guest OS take care of the timesync. This is the "accepted" method and has always worked very well for me. I even have Group Policies setup in my domain to disable Windows Time service for any guest VMs by just adding them to a group.

I'm very new to VirtualBox. I'm trying to get a Windows Server 2008 x64 guest running in VB. Unfortunately timesync is not working. In fact it's not even close. Here's my setup:

Host OS: Arch Linux
VB version: PUEL (sic?) 3.0.2
Guest Additions installed in guest

I've tried this with Windows Time service both enabled and disabled. Guest additions service running and stopped.

On some boots the clock drift is so fast the time is off by several minutes after only about 10 minutes of run time. Othertimes I'll reboot the guest and once the clock stabilizes, it seems to stay in sync. But then I'll reboot it and the machine will come up several minutes off (far enough off that Kerberos is broken but less than an hour off so I know it's not a timezone thing). I have not yet been able to get the time to be correctly matched to the host's clock at bootup so all domain authentication fails - which of course makes some Windows services fail to start.

I've been searching and haven't found much discussion on timesync. The consensus seems to be that once Guest Additions are installed on a Windows guest that time is kept in sync. So far that's not working for me.

Does anyone have any ideas? What logs/events should I be looking for? The VBox.log on the host doesn't seem to be much help. Does the Guest Additions keep a log in the guest's filesystem? Are there any known issues with timesync for Server 2008 guests under VB?

Thanks for any help you can give.

-Phil
puithove
 
Posts: 5
Joined: 6. Aug 2009, 22:49
Primary OS: Linux other
VBox Version: PUEL
Guest OSses: Windows Server 2008

Re: Serious timesync issue

Postby puithove » 7. Aug 2009, 00:58

OK.... nevermind... that was a bit strange but...

Right after I posted that I went ahead and upgraded to VB 3.0.4 and updated the GA inside the guest. It appears to be working now. I've got Windows Time service disabled and it looks like the GA service is manipulating the guest clock. It's almost spot-on after a guest reboot. I've also done a saved-state and brought it back up a few minutes later - the time is behind by quite a bit but I can watch the clock tick fast to catch up. It appears to overshoot and then slows down - drifts back and forth several times and then finally seems to stabilize. I've left it up and running for about 15 minutes and it seems good.

So... fixed... for now. Will keep an eye on it.

Thanks,

-Phil
puithove
 
Posts: 5
Joined: 6. Aug 2009, 22:49
Primary OS: Linux other
VBox Version: PUEL
Guest OSses: Windows Server 2008

Re: Serious timesync issue

Postby Perryg » 7. Aug 2009, 01:08

Good!

I have been looking and trying to find out why it did not work for you. I do not have a problem and figured it had to be something with the VBox timesync.
I do know that using saved state can cause exactly what you are talking about, as it does the same thing for me, but understandable since the time you start with is so far out of sync. Not like booting which polls at open.

I will mark this solved.
Perryg
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Re: Serious timesync issue

Postby puithove » 7. Aug 2009, 13:54

Perryg wrote:Good!

I have been looking and trying to find out why it did not work for you. I do not have a problem and figured it had to be something with the VBox timesync.
I do know that using saved state can cause exactly what you are talking about, as it does the same thing for me, but understandable since the time you start with is so far out of sync. Not like booting which polls at open.

I will mark this solved.


Thanks for looking Perry - I appreciate it. Also thanks for verifying what I was seeing with the clock bouncing around after saved state - I figured it was normal but it's good to have it confirmed.
puithove
 
Posts: 5
Joined: 6. Aug 2009, 22:49
Primary OS: Linux other
VBox Version: PUEL
Guest OSses: Windows Server 2008


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