WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] clock drift in Xen 4.0.0

To: James Harper <james.harper@xxxxxxxxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] clock drift in Xen 4.0.0
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Tue, 25 May 2010 08:58:39 +0100
Cc:
Delivery-date: Tue, 25 May 2010 01:00:39 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <AEC6C66638C05B468B556EA548C1A77D01996B07@trantor>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: Acr71ptLt2yFjkE0Tx2fZTJ4BgsD3QAAJ+3SAAAbAUAAAhuwIw==
Thread-topic: [Xen-devel] clock drift in Xen 4.0.0
User-agent: Microsoft-Entourage/12.24.0.100205
On 25/05/2010 08:01, "James Harper" <james.harper@xxxxxxxxxxxxxxxx> wrote:

>> Are you running NTP? 100ppm drift isn't unbelievable without external
>> synchronisation.
>> 
> 
> That's 7 minutes in front of the Dom0 that it's sitting on. The Dom0
> runs ntp. Another DomU on the same system is ahead by a similar amount
> (9 minutes over 74 days). I thought that with independent_wallclock=0
> that they should stay in step.
> 
> I actually just noticed that I'm running 4.0.0-rc6, not 4.0.0 proper...
> d'oh. I think I should probably update before thinking about it much
> more.

It probably depends on your dom0 and domU kernels also. Have they both been
observed to behave 'properly' before? In particular I'm not sure pv_ops
behaves same as ealrier kernels.

 -- Keir




_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel