[fedora-virt] Windows clock synchronization

["Ján ONDREJ (SAL)"]

Hello,

On Wed, Jul 03, 2013 at 11:08:48AM -0400, Cole Robinson wrote:
> On 07/03/2013 01:54 AM, "Ján ONDREJ (SAL)" wrote:
> > Hello,
> > 
> > On Tue, Jun 25, 2013 at 03:01:15PM -0400, Cole Robinson wrote:
> >> On 06/24/2013 02:18 PM, Ján ONDREJ (SAL) wrote:
> >>> Hello,
> >>>
> >>>   I have clock synchronization problems with Fedora 18/KVM host and windows
> >>> server guests.  Different 64bit windows servers, all has some time
> >>> synchronization problems.
> >>>
> >>>   Some of them will slow down time until time difference is 60 seconds and
> >>> then clock is synchronizes from internet. But 60 seconds is a long time.
> >>> Kerberos authentication sometimes files due to time skew.
> >>>
> >>>   Some machines will run OK day or two, but then clock stops. After some
> >>> hours clock is synchronized again and continues to work properly.
> >>> Curious, that during time is stopped, server works properly (except kerberos
> >>> authentications, which is very time sensitive.
> >>>
> >>>   For example, attaching 2 graphs from 2 windows servers. They show time
> >>> difference measured by check_mk nagios plugin. 10k means 10000 seconds.
> >>>
> >>>   How I should set clock/time/NTP on these guests?
> >>>
> >>>   I have absolutelly no problems with Linux guests, they work perfectly.
> >>>
> >>
> >> Maybe try altering the guest config with:
> >>
> >>       <clock offset='utc'>
> >>         <timer name='pit' tickpolicy='delay'/>
> >>         <timer name='rtc' tickpolicy='catchup'/>
> >>       </clock>
> >>
> >> https://bugs.launchpad.net/nova/+bug/1011848
> >> https://bugzilla.redhat.com/show_bug.cgi?id=828332
> >>
> >> virt-manager/virt-install should be doing this by default.
> > 
> > These didn't helped me to fix my problem. Also trying combinations
> > of these without success:
> > 
> >   <clock offset='variable' adjustment='2' basis='utc'>
> >     <timer name='rtc' tickpolicy='catchup'/>
> >     <timer name='pit' tickpolicy='delay'/>
> >     <timer name='hpet' present='yes'/>
> >   </clock>
> >   <qemu:commandline>
> >     <qemu:arg value='-rtc-td-hack'/>
> >   </qemu:commandline>
> > 
> > Any ideas? Is this a bug?
> > 
> 
> Possibly, please file a Fedora qemu bug and list all the info you've given here.

Looks like there are 2 different clock problems and looks like I can
identify, when they appear.

I have 2 types of machines, 1st with virtio drivers and 2nd without virtio
drivers (default hardware configurations).

1st type - virtio drivers installed, version virtio-win-0.1-59.iso (or 52)
- clock sometimes stops working completelly. I see more hours same time
  on machine.
- screenshot image-virtio.png attached

2nd type - IDE disk and default network (e1000?)
- clock skew is 0-80 seconds. It's better like for 1st type.
- screenshot image-novirtio.png attached

Looks like there are some problems with virtio drivers, which stops
clock. Now I will try, if I can avoid problems with only one virtio driver
(net or disk).

Are ther commercial customers using these drivers?
Also have problems?

					SAL
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