[fedora-virt] Windows clock synchronization

[Cole Robinson]

On 07/04/2013 02:03 AM, "Ján ONDREJ (SAL)" wrote:
> 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?

Best way to get some response for these questions is to file a separate bug
against the virtio-win component in Fedora, where all the virtio-win guys are
watching.

Thanks,
Cole