From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58312) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V088k-00089L-9E for qemu-devel@nongnu.org; Fri, 19 Jul 2013 06:42:23 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V088j-0002v8-5R for qemu-devel@nongnu.org; Fri, 19 Jul 2013 06:42:22 -0400 Received: from e28smtp01.in.ibm.com ([122.248.162.1]:52423) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V088i-0002tj-CM for qemu-devel@nongnu.org; Fri, 19 Jul 2013 06:42:21 -0400 Received: from /spool/local by e28smtp01.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 19 Jul 2013 16:04:29 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id F16801258043 for ; Fri, 19 Jul 2013 16:11:33 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay05.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r6JAg95h29687864 for ; Fri, 19 Jul 2013 16:12:09 +0530 Received: from d28av05.in.ibm.com (loopback [127.0.0.1]) by d28av05.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r6JAgBLJ014580 for ; Fri, 19 Jul 2013 20:42:11 +1000 Message-ID: <51E917F7.9000308@linux.vnet.ibm.com> Date: Fri, 19 Jul 2013 18:41:59 +0800 From: Wenchao Xia MIME-Version: 1.0 References: <1374054136-28741-1-git-send-email-famz@redhat.com> In-Reply-To: <1374054136-28741-1-git-send-email-famz@redhat.com> Content-Type: text/plain; charset=GB2312 Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH v2 00/11] Point-in-time snapshot exporting over NBD List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: kwolf@redhat.com, hbrock@redhat.com, qemu-devel@nongnu.org, rjones@redhat.com, imain@redhat.com, stefanha@redhat.com, pbonzini@redhat.com ÓÚ 2013-7-17 17:42, Fam Zheng дµÀ: > This series adds for point-in-time snapshot NBD exporting based on > blockdev-backup (variant of drive-backup with existing device as target). This > patch is built on top of imain's sync mode patches for drive-backup. > > 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: > Compared with driver-backup, this approach is more flexible in some way, since user can read the content and copy out what he need, with a sacrifice of write of old data to temporary file. Overall it seems good. Dirty change tracking is what miss for a full solution, which naturally exist in backing chain snapshot. > -- Best Regards Wenchao Xia