From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NCwDU-00052d-CO for qemu-devel@nongnu.org; Tue, 24 Nov 2009 09:18:04 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NCwDP-0004x5-6Z for qemu-devel@nongnu.org; Tue, 24 Nov 2009 09:18:03 -0500 Received: from [199.232.76.173] (port=33138 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NCwDO-0004wo-UB for qemu-devel@nongnu.org; Tue, 24 Nov 2009 09:17:58 -0500 Received: from david.siemens.de ([192.35.17.14]:22685) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NCwDO-0003Q9-9V for qemu-devel@nongnu.org; Tue, 24 Nov 2009 09:17:58 -0500 Message-ID: <4B0BEB12.1030408@siemens.com> Date: Tue, 24 Nov 2009 15:17:54 +0100 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [PATCH 0/3 v5] Live migration without shared storage References: <12571692252385-git-send-email-lirans@il.ibm.com> <4AEF2946.1030207@redhat.com> <4AF0081D.1030104@redhat.com> <4B0AD8B3.80406@siemens.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Pierre Riteau Cc: Anthony Liguori , Avi Kivity , Liran Schour , "qemu-devel@nongnu.org" Pierre Riteau wrote: > On 23 nov. 2009, at 19:47, Jan Kiszka wrote: > >> Avi Kivity wrote: >>> On 11/03/2009 11:40 AM, Liran Schour wrote: >>>> - Liran >>>> >>>> Avi Kivity wrote on 02/11/2009 20:47:34: >>>> >>>>> On 11/02/2009 03:40 PM, lirans@il.ibm.com wrote: >>>>> >>>>>> This series adds support for live migration without shared storage, >>>>>> >>>> means >>>> >>>>>> copy the storage while migrating. It was tested with KVM. Supports 2 >>>>>> >>>> ways >>>> >>>>>> to replicate the storage during migration: >>>>>> 1. Complete copy of storage to destination >>>>>> 2. Assuming the storage is cow based, copy only the allocated >>>>>> data, time of the migration will be linear with the amount of allocated >>>>>> data (user responsibility to verify that the same backend file reside >>>>>> on src and destination). >>>>>> >>>>>> Live migration will work as follows: >>>>>> (qemu) migrate -d tcp:0:4444 # for ordinary live migration >>>>>> (qemu) migrate -d blk tcp:0:4444 # for live migration with >>>>>> >>>>> complete storage copy >>>>> >>>>>> (qemu) migrate -d blk inc tcp:0:4444 # for live migration with >>>>>> >>>>> incremental storage copy, storage is cow based. >>>>> >>>>> I'd like to see the syntax generalized. For one, the guest may have >>>>> several disks; an install image cdrom might be available as an nfs image >>>>> but the main storage is local. Secondly, there can be several levels of >>>>> cow and we want to control which one we copy. >>>>> >>>>> I'll leave the exact details to the qpeople, but if we can specify a >>>>> copy depth for each device, where 0=copy nothing, n=copy everything, >>>>> 1=copy the last level (equivalent to -d blk inc) I think we'll have >>>>> covered everything. >>>>> >>>> I propose the following syntax: >>>> migrate [-d] [-b [ ...]] >>>> tcp:: >>>> Where device will be the name of the device: ide0-hd0. And copy_level >>>> will >>>> be integer or n, 0=flat copy of the device, 1=copy the last level ... >>>> n=copy all levels. >>>> All HD devices that will not appear in the command will be treated as >>>> copy_level=0. All devices != BDRV_TYPE_HD will be ignored. >>>> >>>> >>> Looks good. >>> >> Do I get this correctly: this series is now "only" blocked by the >> required rework of its user interface? Is there a schedule for this, a >> v6 roll out? Will it be in time for qemu-0.12? >> >> Jan > > It was committed to the master branch a week ago. Oh, indeed, thanks. Due to the fact that this discussion suggested that there are still open issues, I did not even checked git. And the missing merge notifications contributed to this as well. Anyway, good to see this upstream. /me goes testing. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux