From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56085) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZUaGa-0008Rs-R7 for qemu-devel@nongnu.org; Wed, 26 Aug 2015 08:57:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZUaGZ-0004qx-Va for qemu-devel@nongnu.org; Wed, 26 Aug 2015 08:57:24 -0400 Date: Wed, 26 Aug 2015 13:57:13 +0100 From: Stefan Hajnoczi Message-ID: <20150826125713.GJ30715@stefanha-thinkpad.redhat.com> References: <20150825135753.GA19764@perseus.local> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150825135753.GA19764@perseus.local> Subject: Re: [Qemu-devel] Creating snapshots with specific runtime options List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alberto Garcia Cc: Kevin Wolf , qemu-devel@nongnu.org, qemu-block@nongnu.org, armbru@redhat.com On Tue, Aug 25, 2015 at 04:57:53PM +0300, Alberto Garcia wrote: > As far as I can see there's no way to create a snapshot and either > > a) inherit the runtime options from the original image > b) specify a new set of options > > This comment in external_snapshot_prepare() before calling bdrv_open() > suggests that the problem is known but the discussion was postponed. > > /* TODO Inherit bs->options or only take explicit options with an > * extended QMP command? */ > > I would like to retake this and make it possible. I discussed it > briefly with Stefan on IRC and he said that Kevin might have some > ideas. > > In principle extending the QMP command sounds as simple as adding > 'options': 'BlockdevOptions' to 'blockdev-snapshot-sync', but it's > surely more complicated than that :) Is the 'BlockdevOptions' API even > stable? Some block drivers don't have BlockdevOptions support yet. I think that doesn't prevent us from passing BlockdevOptions to snapshot creation though.