From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38431) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aT9dd-0005Go-DY for qemu-devel@nongnu.org; Tue, 09 Feb 2016 09:51:34 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aT9dY-0002xW-BD for qemu-devel@nongnu.org; Tue, 09 Feb 2016 09:51:33 -0500 Received: from mx2.parallels.com ([199.115.105.18]:55516) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aT9dY-0002vW-5U for qemu-devel@nongnu.org; Tue, 09 Feb 2016 09:51:28 -0500 References: <1454151394-52320-1-git-send-email-vsementsov@virtuozzo.com> <20160203081418.GC25746@ad.usersys.redhat.com> <56B45D3A.405@virtuozzo.com> <20160209142100.GA19303@stefanha-x1.localdomain> From: "Denis V. Lunev" Message-ID: <56B9F9B0.8010801@virtuozzo.com> Date: Tue, 9 Feb 2016 17:37:36 +0300 MIME-Version: 1.0 In-Reply-To: <20160209142100.GA19303@stefanha-x1.localdomain> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 0/6] external backup api List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: kwolf@redhat.com, Vladimir Sementsov-Ogievskiy , Fam Zheng , qemu-devel@nongnu.org, armbru@redhat.com, jsnow@redhat.com On 02/09/2016 05:21 PM, Stefan Hajnoczi wrote: > On Fri, Feb 05, 2016 at 11:28:42AM +0300, Denis V. Lunev wrote: >> On 02/03/2016 11:14 AM, Fam Zheng wrote: >>> On Sat, 01/30 13:56, Vladimir Sementsov-Ogievskiy wrote: >>>> Hi all. >>>> >>>> These series which aims to add external backup api. This is needed to allow >>>> backup software use our dirty bitmaps. >>>> >>>> Vmware and Parallels Cloud Server have this feature. >>> What is the advantage of this appraoch over "drive-backup sync=incremental >>> ..."? >> This will allow third-party vendors to backup QEMU VMs into >> their own formats or to the cloud etc. > Backup software can implement NBD to receive the incremental blocks from > QEMU. Use drive-backup sync=incremental and the backup appliance as the > NBD target. > > It's more complicated to add this QMP command flow to backup software > than to implement NBD. > > Stefan it can, but this is a matter of problem due to the nature of how this software is implemented. Usually it is written in a semi-standard way and it uses "plugins" to actually collect the data, i.e. the code is written in standard interface/real implementation pattern and interfaces are basically the same. With this standard approach backup software is working as an active side of the process, i.e. it performs operations and controls the flow. This means that "non-standard" QEMU technology will be pain here. Den