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-users

Re: [Xen-users] Help: Guest OS time synchronization problem

To: "Chu, Sam" <sam.chu@xxxxxxxxx>
Subject: Re: [Xen-users] Help: Guest OS time synchronization problem
From: Nico Kadel-Garcia <nkadel@xxxxxxxxx>
Date: Mon, 11 Dec 2006 14:50:58 +0000
Cc: xen-users@xxxxxxxxxxxxxxxxxxx
Delivery-date: Mon, 11 Dec 2006 06:51:03 -0800
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; b=To14MVpLGu2uloGeWdxNuLnKy1TJ3SBYUX9bSa6ox7/ykwoSDekB32pilnH/555ABzYuKJaak1UYraxKSXc46LsNZ9hBLIkSxBDQqI1zaRLXE7CM+cb37IXP6uiEa9z9l0+ZOcfXdH8ZT+BrFQIML2fiqXY+4H4DTvLmYMaR00o=
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <5461330FA59EDB46BE9AB8AAF2C431AD0282E540@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <5461330FA59EDB46BE9AB8AAF2C431AD0282E540@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Thunderbird 1.5.0.8 (Windows/20061025)
Chu, Sam wrote:

I am having great difficulty to maintain guest OS time. Here is my environment.

Hardware: Intel Woodcrest processor.

Xen: 3.0.3

Xen OS: Red Hat Enterprise 4 Update 3, x86_64 version

Guest OS: configuration is pretty standard. Please see the end of email.

Guest OS: Red Hat Enterprise 4 Update 3, x86_64, with everything installed, ntpd not running.

/proc/sys/xen/independent_wallclock = 0

/proc/sys/xen/permitted_clock_jitter = 10000000


NTP should run out of Dom0: that seems to correctly set NTP for all DomU's.

Do not run independent, local hardware clocks, if you can reasonably avoid it. Seriously: I'm afraid the kind of time drift you're seeing is typical for overclocked, overheated, low quality motherboards with clock chips purchased at an "OEM discount" from the back of somebody's bicycle in Taiwan. Unfortunately, I've seen too much of that kind of hardware in use for Beowulf clusters.


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

<Prev in Thread] Current Thread [Next in Thread>