From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=43316 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Ptyvq-00029T-Ne for qemu-devel@nongnu.org; Mon, 28 Feb 2011 03:58:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ptyvp-0002QX-Du for qemu-devel@nongnu.org; Mon, 28 Feb 2011 03:58:18 -0500 Received: from mx1.redhat.com ([209.132.183.28]:20094) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ptyvo-0002QN-Vy for qemu-devel@nongnu.org; Mon, 28 Feb 2011 03:58:17 -0500 Message-ID: <4D6B639E.5000109@redhat.com> Date: Mon, 28 Feb 2011 10:58:06 +0200 From: Dor Laor MIME-Version: 1.0 Subject: Re: [Qemu-devel] Re: [patch 2/3] Add support for live block copy References: <20110222170004.808373778@redhat.com> <20110222170115.710717278@redhat.com> <4D642181.4080509@codemonkey.ws> <20110222210735.GA9372@amt.cnet> <4D64266A.3060106@codemonkey.ws> <20110222230935.GA11082@amt.cnet> <4D644343.4050800@codemonkey.ws> <4D65051A.6070707@redhat.com> <4D651B20.70405@codemonkey.ws> <4D652852.60505@redhat.com> <4D652F73.3000305@codemonkey.ws> <4D65324A.5080408@redhat.com> <4D65359E.3040008@codemonkey.ws> <4D65416D.8040803@redhat.com> <4D656B97.5030301@codemonkey.ws> <4D661CB8.6010305@redhat.com> <4D667287.9010005@codemonkey.ws> <4D6677BE.2030009@redhat.com> <4D669C46.40909@codemonkey.ws> <4D6A150B.8030205@redhat.com> <4D6A1FA4.9040809@redhat.com> <4D6A566F.1060807@codemonkey.ws> <4D6A757C.30003@redhat.com> <4D6A8900.8090504@codemonkey.ws> In-Reply-To: <4D6A8900.8090504@codemonkey.ws> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Reply-To: dlaor@redhat.com List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: libvir-list , Jes.Sorensen@redhat.com, Marcelo Tosatti , Avi Kivity , qemu-devel@nongnu.org On 02/27/2011 07:25 PM, Anthony Liguori wrote: > On 02/27/2011 10:02 AM, Dor Laor wrote: >> On 02/27/2011 03:49 PM, Anthony Liguori wrote: >>> On 02/27/2011 03:55 AM, Dor Laor wrote: >>>> What about a simpler approach were QMP events will be written to a >>>> event-log-file (or even named pipe). >>> >>> The management tool can just use a small daemon that does nothing other >>> than write QMP events to a log. There's no real need for this code to >>> live in QEMU. >>> >> >> IIUC in case the management daemon will run qemu using named pipe for >> qmp it will happen automatically. > > No, the event model is changing (it was always intended to change > though). Events will need explicit registration so it's necessary to > have bidirectional communication. But the mgmt->qemu direction is only about event registration, it's not valuable info. It's a simpler approach than relaying on another config file and it is safer than having a separate mgmt daemon to log these events. Cross posting to libvirt-list to hear their view. > > So you can't just do -qmp foo -chardev file:event.log,id=foo. You won't > actually see most of the events. > > Regards, > > Anthony Liguori > >> If you agree to this approach it will simplify the more complex config >> file option (although it is nice to have as independent option for >> single hosts managed by simpler mgmts) >> >>> Since events are posted, even if we wrote it in QEMU, the event wouldn't >>> be guaranteed on disk by the time the event invocation returns. >>> >>> Regards, >>> >>> Anthony Liguori >>> >> >> > >