From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57714) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V1Rmj-0008AL-Vn for qemu-devel@nongnu.org; Mon, 22 Jul 2013 21:53:07 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V1Rmj-0001mX-4M for qemu-devel@nongnu.org; Mon, 22 Jul 2013 21:53:05 -0400 Received: from e28smtp03.in.ibm.com ([122.248.162.3]:39779) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V1Rmi-0001ld-GS for qemu-devel@nongnu.org; Mon, 22 Jul 2013 21:53:05 -0400 Received: from /spool/local by e28smtp03.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 23 Jul 2013 07:16:11 +0530 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id AA8B8394004E for ; Tue, 23 Jul 2013 07:22:51 +0530 (IST) Received: from d28av05.in.ibm.com (d28av05.in.ibm.com [9.184.220.67]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r6N1ro2I39714920 for ; Tue, 23 Jul 2013 07:23:51 +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 r6N1qtUM018957 for ; Tue, 23 Jul 2013 11:52:55 +1000 Message-ID: <51EDE1F0.9010705@linux.vnet.ibm.com> Date: Tue, 23 Jul 2013 09:52:48 +0800 From: Wenchao Xia MIME-Version: 1.0 References: <1374054136-28741-1-git-send-email-famz@redhat.com> <51E917F7.9000308@linux.vnet.ibm.com> In-Reply-To: <51E917F7.9000308@linux.vnet.ibm.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 2013-7-19 18:41, Wenchao Xia дµÀ: > 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. > >> > > Any one is doing dirty tracking feature? If no, I'd like to draft a version based on add-cow. -- Best Regards Wenchao Xia