From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dor Laor Subject: Re: Live Migration, DRBD Date: Fri, 25 Jul 2008 02:02:55 +0300 Message-ID: <48890A1F.4010404@qumranet.com> References: <4888C5E9.2050606@borg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Kent Borg Return-path: Received: from il.qumranet.com ([212.179.150.194]:43386 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754539AbYGXXEc (ORCPT ); Thu, 24 Jul 2008 19:04:32 -0400 In-Reply-To: <4888C5E9.2050606@borg.org> Sender: kvm-owner@vger.kernel.org List-ID: Kent Borg wrote: > I am very happy to discover that KVM does live migration. Now I am > figuring out whether it will work for me. > > What I have in mind is to use DRBD for the file system image. The > problem is that during the migration I want to shift the file system > access at the moment when the VM has quit running on the host it is > leaving but before it starts running on the host where it is arriving. > Is there a hook to let me do stuff at this point? > > This is what I want to do: > > On the departing machine... > > - VM has stopped here > - umount the volume with the VM file system image > - mark volume in DRDB as secondary > > > On the arriving machine... > > - mark volume in DRBD as primary > - mount the volume with the VM file system image > - VM can now start here > > > Is there a way? > > No, but one can add such pretty easy. The whole migration code is in one file qemu/migration.c You can add a parameter to qemu migration command to specify a script that should be called on migration end event (similar to the tap script). > Thanks, > > -kb > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >