[fedora-virt] Windows clock synchronization

[Cole Robinson]

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.