From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nils Cant Subject: Is it possible to live migrate guest OS'es between different versions of kvm/qemu-kvm? Date: Thu, 26 Aug 2010 16:07:35 +0200 Message-ID: <4C767527.2060208@kangaroot.net> 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 mx-be.kangaroot.net ([62.213.203.171]:40683 "EHLO mx-be.kangaroot.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752517Ab0HZOIr (ORCPT ); Thu, 26 Aug 2010 10:08:47 -0400 Received: from 62-213-203-169.colo.kangaroot.net ([62.213.203.169] helo=zimbra.kangaroot.net) by mx-be.kangaroot.net with esmtp (Exim 4.69) (envelope-from ) id 1Ood8F-0005kt-Sk for kvm@vger.kernel.org; Thu, 26 Aug 2010 16:08:44 +0200 Received: from localhost (localhost.localdomain [127.0.0.1]) by zimbra.kangaroot.net (Postfix) with ESMTP id CDE48F4CB4 for ; Thu, 26 Aug 2010 16:08:40 +0200 (CEST) Received: from zimbra.kangaroot.net ([127.0.0.1]) by localhost (zimbra.kangaroot.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 5rWp2qkmJAdg for ; Thu, 26 Aug 2010 16:08:38 +0200 (CEST) Received: from [10.0.14.1] (office2.antwerp.kangaroot.net [82.146.101.162]) by zimbra.kangaroot.net (Postfix) with ESMTPSA id 837C6F4CAD for ; Thu, 26 Aug 2010 16:08:38 +0200 (CEST) Sender: kvm-owner@vger.kernel.org List-ID: Hi, I currently have a couple of Debian KVM servers with all a different version of kvm or qemu-kvm. I can live migrate a guest OS from one server to the other just fine, as long as the version of qemu-kvm is the same. (Thanks to Gleb Natapov who helped me solve my ARP announce problem yesterday) However, when I try to migrate a guest to a server running a newer (or older) version of qemu-kvm, I run into problems. I think this is because the xml configuration differs slightly between version. For example, if I try to migrate from a server running qemu-kvm 0.11.0 to one running qemu-kvm 0.12.4, I get the following error: virt01:~# virsh migrate --live testserver qemu+ssh://192.168.1.7/system error: internal error unable to reserve PCI address 0:0:3 When migrating from kvm 85 to qemu-kvm 0.11.0: virt02:~# virsh migrate --live testserver qemu+ssh://192.168.1.2/system error: Unknown failure Migrating one from 0.12.4 to 0.11.0 just completely breaks libvirt, forcing me to kill -9 libvirtd and the kvm instance, etc. I believe this is caused in part because different versions of qemu-kvm need different xml configurations. To run my testserver on 0.12.4 for example, I need to delete the lines with the PCI id's, just to be able to start the it. So, is there a way to make this work? Perhaps without libvirt? Or tell libvirt to not send the config file when doing a live migrate, and use the xml in /etc/libvirt/qemu instead somehow? Thanks in advance, Nils