From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50392) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WLEFH-0003dp-BB for qemu-devel@nongnu.org; Wed, 05 Mar 2014 11:00:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WLEF2-0005rb-CD for qemu-devel@nongnu.org; Wed, 05 Mar 2014 11:00:35 -0500 Received: from cantor2.suse.de ([195.135.220.15]:54544 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WLEF2-0005r4-6e for qemu-devel@nongnu.org; Wed, 05 Mar 2014 11:00:20 -0500 Message-ID: <531749DC.6090402@suse.de> Date: Wed, 05 Mar 2014 16:59:24 +0100 From: =?ISO-8859-1?Q?Andreas_F=E4rber?= MIME-Version: 1.0 References: <1729828.TVLplOUlZS@skrypuch> In-Reply-To: <1729828.TVLplOUlZS@skrypuch> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] Live migration results in non-working virtio-net device (sometimes) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Neil Skrypuch , qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Juan Quintela Am 30.01.2014 19:23, schrieb Neil Skrypuch: > First, let me briefly outline the way we use live migration, as it is p= robably=20 > not typical. We use live migration (with block migration) to make backu= ps of=20 > VMs with zero downtime. The basic process goes like this: >=20 > 1) migrate src VM -> dest VM > 2) migration completes > 3) cont src VM > 4) gracefully shut down dest VM > 5) dest VM's disk image is now a valid backup >=20 > In general, this works very well. >=20 > Up until now we have been using qemu-kvm 1.1.2 and have not had any iss= ues=20 > with the above process. I am now attempting to upgrade us to a newer ve= rsion=20 > of qemu, but all newer versions I've tried occasionally result in the v= irtio- > net device ceasing to function on the src VM after step 3. While I don't know this particular symptom, I can definitely tell you that migrating from qemu-kvm to qemu is bound to fail unless you enable at least a version_id change in piix4.c, possibly also in kvmvapic.c. Such errors would lead to migration not successfully completing though, with cryptic error on the dest side. Regards, Andreas --=20 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg, Germany GF: Jeff Hawn, Jennifer Guild, Felix Imend=F6rffer; HRB 16746 AG N=FCrnbe= rg