From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40907) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W8MsN-0000Wl-IH for qemu-devel@nongnu.org; Tue, 28 Jan 2014 23:35:53 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W8MsH-0007vV-J6 for qemu-devel@nongnu.org; Tue, 28 Jan 2014 23:35:47 -0500 Received: from mx1.redhat.com ([209.132.183.28]:9576) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W8MsH-0007vQ-9r for qemu-devel@nongnu.org; Tue, 28 Jan 2014 23:35:41 -0500 Date: Wed, 29 Jan 2014 12:35:38 +0800 From: Fam Zheng Message-ID: <20140129043401.GA13739@T430> References: <1390794497-26281-1-git-send-email-famz@redhat.com> <20140128143136.GB1993@stefanha-thinkpad> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140128143136.GB1993@stefanha-thinkpad> Subject: Re: [Qemu-devel] [PATCH v12 00/11] Drop in_use from BlockDriverState and enable point-in-time snapshot exporting over NBD List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: kwolf@redhat.com, rjones@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org, imain@redhat.com, stefanha@redhat.com, pbonzini@redhat.com On Tue, 01/28 15:31, Stefan Hajnoczi wrote: > On Mon, Jan 27, 2014 at 11:48:06AM +0800, Fam Zheng wrote: > > This series adds for point-in-time snapshot NBD exporting based on > > blockdev-backup (variant of drive-backup with existing device as target). > > > > We get a thin point-in-time snapshot by COW mechanism of drive-backup, and > > export it through built in NBD server. The steps are as below: > > > > 1. (SHELL) qemu-img create -f qcow2 BACKUP.qcow2 > > > > (Alternatively we can use -o backing_file=RUNNING-VM.img to omit explicitly > > providing the size by ourselves, but it's risky because RUNNING-VM.qcow2 is > > used r/w by guest. Whether or not setting backing file in the image file > > doesn't matter, as we are going to override the backing hd in the next > > step) > > > > 2. (QMP) blockdev-add backing=source-drive file.driver=file file.filename=BACKUP.qcow2 id=target0 if=none driver=qcow2 > > > > (where source-drive is the running BlockDriverState name for > > RUNNING-VM.img. This patch implements "backing=" option to override > > backing_hd for added drive) > > > > 3. (QMP) blockdev-backup device=source-drive sync=none target=target0 > > > > (this is the QMP command introduced by this series, which use a named > > device as target of drive-backup) > > > > 4. (QMP) nbd-server-add device=target0 > > > > When image fleecing done: > > > > 1. (QMP) block-job-cancel device=source-drive > > > > 2. (HMP) drive_del target0 > > > > 3. (SHELL) rm BACKUP.qcow2 > > Seems to work as advertized but do you have qemu-iotests for > blockdev-backup and image fleecing in particular? I'll respin to address the comment you left and add test cases for blockdev-backup and image fleecing. Thanks for the review. :) Fam