From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:40456)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <dovgaluk@ispras.ru>) id 1bmLSQ-0004bH-0c
	for qemu-devel@nongnu.org; Tue, 20 Sep 2016 09:51:34 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <dovgaluk@ispras.ru>) id 1bmLSJ-0005BR-WC
	for qemu-devel@nongnu.org; Tue, 20 Sep 2016 09:51:33 -0400
Received: from mail.ispras.ru ([83.149.199.45]:36890)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <dovgaluk@ispras.ru>) id 1bmLSJ-00052V-OE
	for qemu-devel@nongnu.org; Tue, 20 Sep 2016 09:51:27 -0400
From: "Pavel Dovgalyuk" <dovgaluk@ispras.ru>
References: <20160920123126.5400.29283.stgit@PASHA-ISP.def.inno>
	<20160920123149.5400.87854.stgit@PASHA-ISP.def.inno>
	<85a6ea4b-880c-cb06-edc1-af19b480ccd3@redhat.com>
	<002301d2133c$18cbf170$4a63d450$@ru>
	<d228866f-1cdb-1518-c479-079955121153@redhat.com>
	<002b01d21344$18909c80$49b1d580$@ru>
	<f80b8906-c7bf-f9a7-adf0-7d981eebbc9a@redhat.com>
In-Reply-To: <f80b8906-c7bf-f9a7-adf0-7d981eebbc9a@redhat.com>
Date: Tue, 20 Sep 2016 16:51:15 +0300
Message-ID: <002c01d21346$0e9fd540$2bdf7fc0$@ru>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="utf-8"
Content-Transfer-Encoding: 7bit
Content-Language: ru
Subject: Re: [Qemu-devel] [PATCH v3 4/8] replay: save/load initial state
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: 'Paolo Bonzini' <pbonzini@redhat.com>, 'Pavel Dovgalyuk' <pavel.dovgaluk@ispras.ru>, qemu-devel@nongnu.org
Cc: peter.maydell@linaro.org, jasowang@redhat.com, quintela@redhat.com, mst@redhat.com, 'Kevin Wolf' <kwolf@redhat.com>

> From: Paolo Bonzini [mailto:pbonzini@redhat.com]
> On 20/09/2016 15:37, Pavel Dovgalyuk wrote:
> >> c) no rrsnapshot implies -snapshot:
> >>    without overlay:
> >>       -drive file=disk.raw,if=none,id=img-direct
> >>       -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay
> >>
> >>    with overlay:
> >>      -drive file=foo.qcow2,if=none,id=img-direct
> >>      -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay
> >>      -icount ...,rrsnapshot=snapname
> >
> > But how record will create this overlay?
> > This method requires creating overlay manually, because backing file is
> > not specified at all.
> 
> You create it manually, or you just use a .qcow2 file to begin with for
> your image.  Then:
> 
> 1) if you specify no snapshot, a temporary .qcow2 file is created on top
> so data is not destroyed
> 
> 2) if you specify a snapshot, that snapshot is preserved (so you don't
> lose the base state even though the file changes)

Now I see.
This seems ok, but:
 - this approach adds some garbage to original disk image
 - won't work with raw images

Pavel Dovgalyuk