From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33905) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aGqyQ-0000Z7-1F for qemu-devel@nongnu.org; Wed, 06 Jan 2016 11:30:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aGqyL-0001o3-QS for qemu-devel@nongnu.org; Wed, 06 Jan 2016 11:30:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60132) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aGqyL-0001nr-Kw for qemu-devel@nongnu.org; Wed, 06 Jan 2016 11:30:05 -0500 References: <6ca84848.f052.15211b20317.Coremail.magazine.lihuiba@163.com> <568BCB6C.7010709@redhat.com> <557a47a5.3564.15214d76e2e.Coremail.magazine.lihuiba@163.com> <568D2D00.3050600@redhat.com> <568D3EDD.1090205@redhat.com> <568D40AC.5050901@redhat.com> From: Max Reitz Message-ID: <568D4109.5060107@redhat.com> Date: Wed, 6 Jan 2016 17:30:01 +0100 MIME-Version: 1.0 In-Reply-To: <568D40AC.5050901@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ibrBbRpo4o2R1A3k5AD1bTDLPgqWAQfWQ" Subject: Re: [Qemu-devel] qcow2 snapshot + resize List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake , lihuiba Cc: "qemu-devel@nongnu.org" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --ibrBbRpo4o2R1A3k5AD1bTDLPgqWAQfWQ Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 06.01.2016 17:28, Eric Blake wrote: > On 01/06/2016 09:20 AM, Max Reitz wrote: >=20 >>> If I take a snapshot while the guest sees a 1G disk, then resize the >>> disk to 2G, then roll back to the point in time of the snapshot, I'd >>> expect the disk to roll back to 1G in size. Anything else is likely = to >>> confuse the guest. And that's what current resize support already do= es >>> (it only resizes the active image, not the snapshots). >> >> No, the current resize operation just refuses to resize the image if i= t >> has any snapshots. Snapshots currently do not store the size of the >> image when they were created. >=20 > Huh? I thought that we specifically added bytes 48-55 per snapshot entr= y > in the qcow2v3 description specifically so that internal snapshots DO > record the size of the image when the snapshot was created. Oh, you're right! Well, then that was probably the intention, yes. However, resizing an image with snapshots will still fail. Max --ibrBbRpo4o2R1A3k5AD1bTDLPgqWAQfWQ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAEBCAAGBQJWjUEJAAoJEDuxQgLoOKytyWgIAJsFiMgSoKA7pMaHKg8iAAKd Aufiy3nCLpIEKWwg8Zec3jqtF9MBNpDCfVLeulKvR/4f4PQ6PTgBbb3qJX1tBk0M lntXE1sTa7HM3zxccDFXLgbC4MAMrxh5fVtd+7up/86F0reQ9byYCFuLKGqQpqLK 2lAnDcAap+vEOYHVIkOAJudc6FAVK4lILPZePtkauiTwCTQc8dch1sgiT+o7wddp YloHKB3Jo7KJvgLB6bgfivpM+Ms3XXEuiULojX2IeQHboPwGsCI27xNY/wdOaE8t 8hGet7a+PA7baU6fKUzMhabqKuxrlgDhIgX7LnduE9QXWq7bwWp1NDVSE2Q6bqk= =BJOa -----END PGP SIGNATURE----- --ibrBbRpo4o2R1A3k5AD1bTDLPgqWAQfWQ--