From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:35000)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <stefanha@gmail.com>) id 1Ypa38-00036R-Sf
	for qemu-devel@nongnu.org; Tue, 05 May 2015 06:26:06 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <stefanha@gmail.com>) id 1Ypa37-0002aa-N1
	for qemu-devel@nongnu.org; Tue, 05 May 2015 06:26:02 -0400
Date: Tue, 5 May 2015 11:25:46 +0100
From: Stefan Hajnoczi <stefanha@gmail.com>
Message-ID: <20150505102546.GB3149@stefanha-thinkpad.redhat.com>
References: <5541605C.2090904@redhat.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha1;
	protocol="application/pgp-signature"; boundary="XOIedfhf+7KOe/yw"
Content-Disposition: inline
In-Reply-To: <5541605C.2090904@redhat.com>
Subject: Re: [Qemu-devel] [Qemu-block] [RFC] Differential Backups
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: John Snow <jsnow@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>, Qemu-block <qemu-block@nongnu.org>, qemu-devel <qemu-devel@nongnu.org>


--XOIedfhf+7KOe/yw
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Wed, Apr 29, 2015 at 06:51:08PM -0400, John Snow wrote:
> This is a feature that should be very easy to add on top of the existing
> incremental feature, since it's just a difference in how the bitmap is
> treated:
>=20
> Incremental
> - Links to the last incremental (managed by libvirt)
> - Clears the bitmap after creation
>=20
> Differential:
> - Links to the last full backup always (managed by libvirt)
> - Does not clear the bitmap after creation
>=20
> No biggie.

Differential backups can be done using incremental backup functionality
in QEMU:

The client application points QEMU to the same target repeatedly instead
of keeping separate incremental backups.

Stefan

--XOIedfhf+7KOe/yw
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1

iQEcBAEBAgAGBQJVSJqqAAoJEJykq7OBq3PImS8H/j3ZhrtAV5xuwPrtVev+NhDv
w/ADa32ewoMKXkRixwHsO7qX0EGkfnmU4zaVNuOL9spxFabDxyKDpKRt5YqUfdsW
PBxJbWLo0zCBF1AS3cqCSMuugcnW08bu5wjJOT0nuksiCBdBKW14V0Hh+LdmFWs7
FGIrxOC815QTujsKN0qZgGdpCTdIrdiekgW9Rd/IdAz3cTzOWnkGg0vQwWsVQCOL
y1VtLzI4TMJ2+s/ur+JdLfEJ3YsphkXvGIFeiZMGTun15polHN0nN7UITbciK/id
uaX2DSfQBOXvCrprx6hOGx4IFW7EKwA9nCy2ocVomAqNUjdtJtICQSR/Sh4GKQs=
=ldec
-----END PGP SIGNATURE-----

--XOIedfhf+7KOe/yw--