From mboxrd@z Thu Jan 1 00:00:00 1970 From: Espen Berg Subject: Timedrift in KVM guests after livemigration. Date: Thu, 15 Apr 2010 09:35:13 +0200 Message-ID: <4BC6C1B1.5010206@monsternett.no> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from mail2.monsternett.no ([217.171.192.11]:43282 "EHLO mail.monsternett.no" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757344Ab0DOHfz (ORCPT ); Thu, 15 Apr 2010 03:35:55 -0400 Received: from localhost (filter.monsternett.no [217.171.192.14]) by mail.monsternett.no (Postfix) with ESMTP id 895D4C065483 for ; Thu, 15 Apr 2010 09:33:22 +0200 (CEST) Received: from mail.monsternett.no ([217.171.192.10]) by localhost (filter.monsternett.no [217.171.192.14]) (amavisd-new, port 10024) with ESMTP id WKbjv3u5DhJ9 for ; Thu, 15 Apr 2010 09:35:50 +0200 (CEST) Received: from [217.171.199.6] (ws14.monsternett.no [217.171.199.6]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.monsternett.no (Postfix) with ESMTPSA id 9D819C09BDBF for ; Thu, 15 Apr 2010 09:33:19 +0200 (CEST) Sender: kvm-owner@vger.kernel.org List-ID: We have three KVM hosts that supports live-migration between them, but one of our problems is time drifting. The three frontends has different CPU frequency and the KVM guests adopt the frequency from the host machine where it was first started. Host1: cat /proc/cpuinfo model name : Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz cpu MHz : 2394.048 Host2: cat /proc/cpuinfo model name : Intel(R) Core(TM)2 CPU 6700 @ 2.66GHz cpu MHz : 2659.685 Host3: cat /proc/cpuinfo model name : Intel(R) Xeon(R) CPU E5410 @ 2.33GHz cpu MHz : 2327.507 virsh version Compiled against library: libvir 0.7.6 Using library: libvir 0.7.6 Using API: QEMU 0.7.6 Running hypervisor: QEMU 0.11.0 Is there any solution to our problems, or is a reboot the only safe solution? Regards Espen