From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:55648) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tlsrd-0006Hs-MZ for qemu-devel@nongnu.org; Thu, 20 Dec 2012 22:01:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tlsrc-000593-Dy for qemu-devel@nongnu.org; Thu, 20 Dec 2012 22:01:33 -0500 Received: from e28smtp04.in.ibm.com ([122.248.162.4]:43940) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tlsrb-00057w-QI for qemu-devel@nongnu.org; Thu, 20 Dec 2012 22:01:32 -0500 Received: from /spool/local by e28smtp04.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 21 Dec 2012 08:30:47 +0530 Received: from d28relay05.in.ibm.com (d28relay05.in.ibm.com [9.184.220.62]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id 7B1FEE004B for ; Fri, 21 Dec 2012 08:31:13 +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 qBL31Ju241549838 for ; Fri, 21 Dec 2012 08:31:20 +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 qBL31HkC025186 for ; Fri, 21 Dec 2012 14:01:19 +1100 Message-ID: <50D3D0EF.90903@linux.vnet.ibm.com> Date: Fri, 21 Dec 2012 11:01:03 +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> <24E144B8C0207547AD09C467A8259F75578B47D6@lisa.maurer-it.com> <50D38F0B.4040809@redhat.com> In-Reply-To: <50D38F0B.4040809@redhat.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: Eric Blake Cc: "kwolf@redhat.com" , "aliguori@us.ibm.com" , "stefanha@gmail.com" , "qemu-devel@nongnu.org" , "blauwirbel@gmail.com" , "pbonzini@redhat.com" , Dietmar Maurer 于 2012-12-21 6:19, Eric Blake 写道: > On 12/17/2012 02:58 AM, Dietmar Maurer wrote: >>>>>> Seems this makes it impossible to use external commands to make >>>>> snapshots? >>>>>> >>>>> what command? can you tip more about the case? >>>> >>>> For example, nexenta storage provides an API to create snapshots. We >>>> want to use that. Another example would be to use lvcreate to create lvm >>> snapshots. >>>> >>> I am not familar with those tools, Patch 5 and 6 provides hmp and qmp API, >>> hope you can enlight more what is missing if it can't work with external tool. >> >> We need the ability to create snapshots with external tools - your patch does not support that. >> I think that is a major drawback. > > I think the ability to create snapshots with external tools is going to > require asynchronous snapshots, where the work is divided into several > phases. You'll need qemu to prepare for the snapshot, then the external > tools to create the snapshot, then resume qemu with possibly different > file names as a result of the snapshot being created. I'm certainly > interested in seeing what you come up with, and how libvirt will be able > to interact with it for external tool snapshots. > If libvirt could integrate external tool using code, that would be great. For qemu, My understanding is just to take internal snapshot and stop vm, then let management stack do the things remain. Dietmar, do you think that is all what needed in qemu? -- Best Regards Wenchao Xia