From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:49383) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TUH30-0002NZ-RN for qemu-devel@nongnu.org; Fri, 02 Nov 2012 09:12:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TUH2z-0007MJ-Jb for qemu-devel@nongnu.org; Fri, 02 Nov 2012 09:12:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54079) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TUH2z-0007M8-BZ for qemu-devel@nongnu.org; Fri, 02 Nov 2012 09:12:29 -0400 Message-ID: <5093C6B5.7070901@redhat.com> Date: Fri, 02 Nov 2012 07:12:21 -0600 From: Eric Blake MIME-Version: 1.0 References: <20121102.121505.54777738.k.suzaki@aist.go.jp> <20121102.172447.47346577.k.suzaki@aist.go.jp> In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="------------enig689E14A1138FBCEA92317F99" Subject: Re: [Qemu-devel] live migration which includes previos snapshot List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: Paolo Bonzini , qemu-devel This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig689E14A1138FBCEA92317F99 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 11/02/2012 04:30 AM, Stefan Hajnoczi wrote: > II. If you want to use internal snapshots in a single qcow2 file, you > will need to modify QEMU code more: > 1. Implement BlockDriverState snapshot slave support so a qcow2 > snapshot can be read-only accessed as a BlockDriverState while the > master BlockDriverState for the image still writes into the image > file. This is mainly qcow2 refactoring and block.c glue code. You are not the first to request this - libvirt would also like the ability to have read-only access into the contents of an internal snapshot while the rest of qemu continues to write into the image. > 2. Use Paolo's runtime NBD server to export the snapshot slave when > the VM is forked: An NBD server on top of the read-only state is an additional step that will make access easier. --=20 Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --------------enig689E14A1138FBCEA92317F99 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ iQEcBAEBCAAGBQJQk8a2AAoJEKeha0olJ0NqB9QH/2kqigD9LLZu41WOwvnDkGml x6MAW3do0g08stXeLlJeFS6qiGshaMEprNq1Ih9cafedZwGvCmR83R8HbOOBlzxA Wzgftw0qW8+aA+2/FTngUYKqUlDb9WaFZIfZLxA7Jqhxx02n034gZYwsqCAuSKdi oSPFf5YdbAooPVoPRXp3yzAtlAfYgQDaOTPaAZCFTgSj8L3qgZW7MYZOYd0a2HQV /tdn2GSesIP73wC5BosRR3lb+MxT2jZnbKIVI0DtgQ9z0S5a4cPDX7YJowSBEnNt WE5iv6cvwtOqfFT/Yy8ZjJxcjY6WGmuMColpeo8EXLRRlpexJp/Jhsev4BXVv9Q= =eplJ -----END PGP SIGNATURE----- --------------enig689E14A1138FBCEA92317F99--