Re: Dom0 <> DomU clock sync

["Sébastien RICCIO" <sr@swisscenter.com>]

Hi Keir,

Thank you for your answer.

Ntpd is not running in dom0. I am updating the dom0 time with ntpdate 
(crontab every hour).
Should ntpd be running on dom0 ?

Dom0
[root@xen01 /]# date
Mon Sep  3 15:59:37 CEST 2007

DomU (started 5 hours ago)
ns1 bin # date
Mon Sep  3 15:58:05 CEST 2007

ns1 bin # uptime
 15:58:10 up  5:21,  3 users,  load average: 0.00, 0.00, 0.11


But this is strange... I just rebooted the vm:

Dom0:
[root@xen01 /]# date
Mon Sep  3 16:04:13 CEST 2007

DomU:
ns1 ~ # date
Mon Sep  3 16:02:41 CEST 2007

There is already a difference when the vm is freshly rebooted.
Same after a shutdown/xm create....

Weird... Any idea ?

Thanks again!

-- 
Sébastien Riccio
SwissCenter / OpenBusiness SA
sr@openbusiness.com






Keir Fraser a écrit :
> You're not running ntpd in the domU as well, right? Just worth checking...
> Apart from that I don't think you can be doing anything wrong. Any weirdness
> after long uptime is of course interesting, as it's something that's hard
> for developers to test.
>
> If you create a new domU (doesn't need to be from scratch installation -
> e.g., just restarting a domU, or starting an existing dormant domU, would
> do) then is its time behind dom0, or in sync?
>
>  -- Keir
>
> On 3/9/07 08:45, "Sébastien RICCIO" <sr@swisscenter.com> wrote:
>
>   
>> Hello !
>>
>> Just a quick question about time synchronization between xen dom0 and
>> domUs...
>>
>> We're running Xen 3.1 64-bit, with 32 and 64 bits linux guests.
>>
>> It's up since 89 days and the domU's time is around 5 minutes behind the
>> dom0,
>> which is updated via ntpdate...
>>
>> Any idea why it doesn't sync the guests even that
>> /proc/sys/xen/independent_wallclock is 0 ?
>>
>> Could it be an option that I missed in dom0/domU kernel ?
>>
>> Thanks for your help !
>>
>>     
>
>
>
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>