Mailing List Archive

On 2014-04-17T08:05:43, Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de> wrote:

> I think "Xen live migration" and "correct time" has a lot to do with HA; maybe
> not with the product you have in mind, but with the concept in general.

Sure. But Xen and kernel time keeping developers aren't subscribed to
linux-ha, so this isn't the best list to report or discuss such issues.

> For the problem: I'll retry soo with all the current updates being installed.

Thanks!


Regards,
Lars

--
Architect Storage/HA
SUSE LINUX Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer, HRB 21284 (AG Nürnberg)
"Experience is the name everyone gives to their mistakes." -- Oscar Wilde

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On 04/17/2014 08:05 AM, Ulrich Windl wrote:
>>>> Lars Marowsky-Bree <lmb@suse.com> schrieb am 16.04.2014 um 15:32 in
> Nachricht
> <20140416133251.GE4716@suse.de>:
>> On 2014-04-16T09:18:21, Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>
> wrote:
>>> As it turn out, the time in the VMs is actually wrong after migration:
>>> # ntpq -pn
>>> remote refid st t when poll reach delay offset
>> jitter
> =============================================================================
>> =
>>> 127.127.1.0 .LOCL. 10 l 51 64 377 0.000 0.000
>> 0.001
>>> +132.199.176.18 192.53.103.108 2 u 71 1024 377 0.362 -77840.
>> 2.573
>>> +132.199.176.153 192.53.103.104 2 u 386 1024 377 0.506 -77838.
>> 2.834
>>> *172.20.16.1 132.199.176.153 3 u 391 1024 377 4.140 -77840.
>> 2.744
>>> +172.20.16.5 132.199.176.18 3 u 386 1024 377 3.767 -77841.
>> 1.409
>>> If I want to continue to use NTP, what are the recommendations?
>> Probably a kernel or hypervisor bug. If these are SLES systems, please
>> report (with full versions etc) to NTS, but has little to do with HA.
> Hi!
>
> I think "Xen live migration" and "correct time" has a lot to do with HA; maybe
> not with the product you have in mind, but with the concept in general.
> For the problem: I'll retry soo with all the current updates being installed.
>
> Regards,
> Ulrich
>
>>
>> Regards,
>> Lars
>>
>> --
>> Architect Storage/HA
>> SUSE LINUX Products GmbH, GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer,
>> HRB 21284 (AG Nürnberg)
>> "Experience is the name everyone gives to their mistakes." -- Oscar Wilde
>>
>> _______________________________________________
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>> Linux-HA@lists.linux-ha.org
>> http://lists.linux-ha.org/mailman/listinfo/linux-ha
>> See also: http://linux-ha.org/ReportingProblems
>
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Hi,

should it be not best practice to not use a the hardware clock in any
virtualized environment. I would strongly suggest to use an external
time source.


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>>> Googlemail <mimabroma@googlemail.com> schrieb am 20.04.2014 um 19:08 in
Nachricht <5353FF24.1030603@googlemail.com>:
[...]
> Hi,
>
> should it be not best practice to not use a the hardware clock in any
> virtualized environment. I would strongly suggest to use an external
> time source.

Hi!

From some experience I had with Novell support in the past I learned that the Xen hypervisor uses the hardware clock, and not the software clock to set up clocks in virtual machines. Combined with the fact that SLES (in Xen at least) seems unable to update the hardware clock while running NTP, this would explain what happens if the hardware clock drifts away after some time...

I think there's little the user can do.

Regards,
Ulrich

>
>
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