From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1N5GmY-0001Ay-8b for qemu-devel@nongnu.org; Tue, 03 Nov 2009 05:38:34 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1N5GmS-00019G-Ep for qemu-devel@nongnu.org; Tue, 03 Nov 2009 05:38:32 -0500 Received: from [199.232.76.173] (port=51566 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N5GmS-00018z-0y for qemu-devel@nongnu.org; Tue, 03 Nov 2009 05:38:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:27605) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1N5GmR-000575-EV for qemu-devel@nongnu.org; Tue, 03 Nov 2009 05:38:27 -0500 Message-ID: <4AF0081D.1030104@redhat.com> Date: Tue, 03 Nov 2009 12:38:21 +0200 From: Avi Kivity MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 0/3 v5] Live migration without shared storage References: <12571692252385-git-send-email-lirans@il.ibm.com> <4AEF2946.1030207@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Liran Schour Cc: qemu-devel@nongnu.org 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. -- error compiling committee.c: too many arguments to function