From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37590) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPX2Y-0000tL-Od for qemu-devel@nongnu.org; Thu, 04 Sep 2014 09:25:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XPX2R-0008Ge-B9 for qemu-devel@nongnu.org; Thu, 04 Sep 2014 09:25:30 -0400 Received: from lputeaux-656-01-25-125.w80-12.abo.wanadoo.fr ([80.12.84.125]:44767 helo=paradis.irqsave.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPX2R-0008GV-4a for qemu-devel@nongnu.org; Thu, 04 Sep 2014 09:25:23 -0400 Date: Thu, 4 Sep 2014 15:24:36 +0200 From: =?iso-8859-1?Q?Beno=EEt?= Canet Message-ID: <20140904132435.GA27852@irqsave.net> References: <20140829172218.GD16755@irqsave.net> <20140902092510.GC29067@stefanha-thinkpad.redhat.com> <54065EE7.4080601@redhat.com> <20140903131159.GM28095@stefanha-thinkpad.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20140903131159.GM28095@stefanha-thinkpad.redhat.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] tcmu-runner and QEMU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: =?iso-8859-1?Q?Beno=EEt?= Canet , kwolf@redhat.com, Andy Grover , qemu-devel@nongnu.org, pbonzini@redhat.com The Wednesday 03 Sep 2014 =E0 14:11:59 (+0100), Stefan Hajnoczi wrote : > On Tue, Sep 02, 2014 at 05:20:55PM -0700, Andy Grover wrote: > > On 09/02/2014 02:25 AM, Stefan Hajnoczi wrote: > > > The qemu-lio tool would live in the QEMU codebase and reuse all the > > > infrastructure. For example, it could include a QMP monitor just l= ike > > > the one you are adding to qemu-nbd. > >=20 > > Benoit and I talked a little about QMP on another part of the thread.= .. I > > said I didn't think we needed a QMP monitor in qemu-lio-tcmu, but let= me > > spin up on qemu a little more and I'll be able to speak more intellig= ently. >=20 > The QEMU block layer has useful features that are available as QMP > commands: >=20 > For example, the drive-mirror QMP command copies a disk image to a new > location while still servicing I/O requests. This is used when an > administrator needs to migrate disk images to a new file system or > storage devices without downtime. >=20 > There are other commands for snapshots and backup which are issued via > QMP. >=20 > It might even make sense to make the tcmu interface available at > run-time in QEMU like the run-time NBD server. This allows you to get > at read-only point-in-time snapshots while the guest is accessing the > disk. See the nbd-server-start command in qapi/block.json. >=20 > Stefan Andy: ping I hope we didn't scaried you with our monster block backend and it's associated QMP socket ;)