From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zachary Amsden Subject: Re: Clock issue in Windows XP guests Date: Thu, 04 Mar 2010 05:13:24 -1000 Message-ID: <4B8FCE14.8070808@redhat.com> References: <4B8F80D6.1030703@gilouweb.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Gilles PIETRI Return-path: Received: from mx1.redhat.com ([209.132.183.28]:34067 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753659Ab0CDPNt (ORCPT ); Thu, 4 Mar 2010 10:13:49 -0500 In-Reply-To: <4B8F80D6.1030703@gilouweb.com> Sender: kvm-owner@vger.kernel.org List-ID: On 03/03/2010 11:43 PM, Gilles PIETRI wrote: > Hi, > > I have a host running a 2.6.32.7 kernel, and I'm using qemu-kvm > 0.12.2. I have multiple guests, and one of them is running Windows XP. > If I stare at the clock, I see that every now & then (~5s), it slows > down a bit, and then try to cope with it. If I run some NTP > synchronization software like ntpd, the offset is as high as 1s lost > every 10s or so, which makes it impossible to use anything time based > on the guest (audio stuff, mainly). > > I tried messing (as said on IRC) with the -rtc parameters, but to no > avail. I tried the driftfix=slew option found in the --help output, > but it says that driftfix is not a valid setting for rtc.. And anyway, > I have no idea what this does (I'll be reading about it probably...) > > I've seen something remotely connected to this on the proxmox forum, > but it was not that helpful (and proxmox runs qemu 0.11.x as it seems): > http://forum.proxmox.com/threads/2050-Slow-clock-time-drift-in-windows-guests?p=17962 > > > I remember using the -rtc-td-hack (and in fact, just read again about > it here: > http://forum.proxmox.com/threads/2381-Recommended-clock-source-for-KVM-guests), > but it's not there anymore in 0.12.x, and I have no idea what it used > to do (going on for some reading as well, when I have some time ;)) > > Oh, and the guests running linux are working just fine, and have no > clock issue. > > Has anyone encountered such a problem? No, but I'd certainly like to fix it. Can you send basic host information like /proc/cpuinfo, dmesg from kernel? If you run the one Windows XP guest alone, does it run better or still the same? Thanks, Zach