From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?S=E9bastien_RICCIO?= Subject: Re: Dom0 <> DomU clock sync Date: Mon, 03 Sep 2007 16:07:13 +0200 Message-ID: <46DC1511.6020302@swisscenter.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: xen-devel List-Id: xen-devel@lists.xenproject.org Hi Keir, Thank you for your answer. Ntpd is not running in dom0. I am updating the dom0 time with ntpdate=20 (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! --=20 S=E9bastien Riccio SwissCenter / OpenBusiness SA sr@openbusiness.com Keir Fraser a =E9crit : > 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 weir= dness > after long uptime is of course interesting, as it's something that's ha= rd > 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, wou= ld > do) then is its time behind dom0, or in sync? > > -- Keir > > On 3/9/07 08:45, "S=E9bastien RICCIO" wrote: > > =20 >> 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 t= he >> 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 ! >> >> =20 > > > > > =20