From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54407) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TlCM6-0007NP-NJ for qemu-devel@nongnu.org; Wed, 19 Dec 2012 00:38:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TlCM5-0004fi-PA for qemu-devel@nongnu.org; Wed, 19 Dec 2012 00:38:10 -0500 Received: from e28smtp09.in.ibm.com ([122.248.162.9]:41046) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TlCM5-0004fV-3x for qemu-devel@nongnu.org; Wed, 19 Dec 2012 00:38:09 -0500 Received: from /spool/local by e28smtp09.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 19 Dec 2012 11:07:36 +0530 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by d28dlp03.in.ibm.com (Postfix) with ESMTP id 0B539125804C for ; Wed, 19 Dec 2012 11:07:54 +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 qBJ5bujk51314808 for ; Wed, 19 Dec 2012 11:07:57 +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 qBJ5bvw9024550 for ; Wed, 19 Dec 2012 16:37:57 +1100 Message-ID: <50D15285.7020902@linux.vnet.ibm.com> Date: Wed, 19 Dec 2012 13:37:09 +0800 From: Wenchao Xia MIME-Version: 1.0 References: <1355725509-5429-1-git-send-email-xiawenc@linux.vnet.ibm.com> <1355725509-5429-5-git-send-email-xiawenc@linux.vnet.ibm.com> <24E144B8C0207547AD09C467A8259F75578B461B@lisa.maurer-it.com> <50CECBFA.6090000@linux.vnet.ibm.com> <24E144B8C0207547AD09C467A8259F75578B46F4@lisa.maurer-it.com> <50CEDD39.6010803@linux.vnet.ibm.com> <24E144B8C0207547AD09C467A8259F75578B4977@lisa.maurer-it.com> <50D045A4.7030706@linux.vnet.ibm.com> <24E144B8C0207547AD09C467A8259F75578B5D89@lisa.maurer-it.com> <50D135B4.1030704@linux.vnet.ibm.com> <24E144B8C0207547AD09C467A8259F75578B6A00@lisa.maurer-it.com> In-Reply-To: <24E144B8C0207547AD09C467A8259F75578B6A00@lisa.maurer-it.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] [PATCH 4/6] snapshot: implemention of common API to take snapshots List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Dietmar Maurer Cc: "kwolf@redhat.com" , "aliguori@us.ibm.com" , "stefanha@gmail.com" , "qemu-devel@nongnu.org" , "blauwirbel@gmail.com" , "pbonzini@redhat.com" 于 2012-12-19 12:55, Dietmar Maurer 写道: >> OK, I think underlying storage is another level of issue, just wondering what >> this patch miss to stop you use external tool, did you called a LVM/nexenta C >> API in previous patch? > > The trick is to do thing step by step > > 1.) save state > 2.) create internal snapshots > 3.) call external tools to create snapshots > ... > > 1 and 2 is done inside qemu, 3 is done from the management tool. > > You use qmp_transactions, which makes that impossible. > There is simple HMP/QMP API for 2), in patch 5,6, not in the form of qmp_transaction, simply blkdev_snapshot() form. 1) will be added later, which have some issue need to solve now. qmp_transaction() or blkdev_snapshot() call the common API in this patch. "common API" in this patch is for qemu not user, it is hidden, maybe that caused misunderstanding. -- Best Regards Wenchao Xia