From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36098) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VqZpO-0006dL-Tv for qemu-devel@nongnu.org; Tue, 10 Dec 2013 21:47:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VqZpI-0001sk-U3 for qemu-devel@nongnu.org; Tue, 10 Dec 2013 21:47:10 -0500 Received: from mx1.redhat.com ([209.132.183.28]:17052) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VqZpI-0001rd-Lz for qemu-devel@nongnu.org; Tue, 10 Dec 2013 21:47:04 -0500 Message-ID: <52A7D219.1070703@redhat.com> Date: Wed, 11 Dec 2013 10:46:49 +0800 From: Fam Zheng MIME-Version: 1.0 References: <1385627982-14675-1-git-send-email-famz@redhat.com> In-Reply-To: <1385627982-14675-1-git-send-email-famz@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v6 00/10] 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: qemu-devel@nongnu.org Cc: kwolf@redhat.com, pbonzini@redhat.com, =?UTF-8?B?QmVub8OudCBDYW5ldA==?= , imain@redhat.com, stefanha@redhat.com On 2013=E5=B9=B411=E6=9C=8828=E6=97=A5 16:39, 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=3DRUNNING-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 imag= e file > doesn't matter, as we are going to override the backing hd in the = next > step) > > 2. (QMP) blockdev-add backing=3Dsource-drive file.driver=3Dfile file.= filename=3DBACKUP.qcow2 id=3Dtarget0 if=3Dnone driver=3Dqcow2 > > (where ide0-hd0 is the running BlockDriverState name for > RUNNING-VM.img. This patch implements "backing=3D" option to overr= ide > backing_hd for added drive) > > 3. (QMP) blockdev-backup device=3Dsource-drive sync=3Dnone target=3Dt= arget0 > > (this is the QMP command introduced by this series, which use a na= med > device as target of drive-backup) > > 4. (QMP) nbd-server-add device=3Dtarget0 > > When image fleecing done: > > 1. (QMP) block-job-complete device=3Dide0-hd0 > > 2. (HMP) drive_del target0 > > 3. (SHELL) rm BACKUP.qcow2 > > v6: Address Paolo's comments, (except for bitmask): > - Add blocker for all backing_hd references, a relatively big chan= ge, some > patches are reordered. > - Introduce a few other necessary patches. > - Move two snapshot checks into bdrv_snapshot_*. > > The interface is unchanged. > Hi, Based on the size of change, this series needs some more review before=20 merging. And I'd like to know if there is any concern or objection with=20 op_blocker introduced here. I would like to base my next series=20 (incremental backup with dirty bitmap) on it. Any more reviews/comments? Thanks! Fam