From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LYWjA-0002IT-8F for qemu-devel@nongnu.org; Sat, 14 Feb 2009 21:27:28 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LYWj7-0002I5-PY for qemu-devel@nongnu.org; Sat, 14 Feb 2009 21:27:26 -0500 Received: from [199.232.76.173] (port=53054 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LYWj7-0002I2-Kf for qemu-devel@nongnu.org; Sat, 14 Feb 2009 21:27:25 -0500 Received: from mail2.shareable.org ([80.68.89.115]:43970) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LYWj7-00081k-2v for qemu-devel@nongnu.org; Sat, 14 Feb 2009 21:27:25 -0500 Date: Sun, 15 Feb 2009 02:27:19 +0000 From: Jamie Lokier Subject: Re: [Qemu-devel] Re: qcow2 corruption observed, fixed by reverting old change Message-ID: <20090215022719.GC9281@shareable.org> References: <20090211070049.GA27821@shareable.org> <49955681.9070301@suse.de> <20090213162336.GI18471@shareable.org> <499745A1.3040707@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <499745A1.3040707@redhat.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Dor Laor Cc: Marc Bevand , qemu-devel@nongnu.org, Gleb Natapov , kvm@vger.kernel.org Dor Laor wrote: > Both qcow2 and vmdk have the ability to keep 'external' snapshots. I didn't see any mention of this in QEMU's documentation. One of the most annoying features of qcow2 is "savevm" storing all VM snapshots in the same qcow2 file. Is this not true? > In addition to what you wrote, qcow2 is missing journal for its meta > data and > also performs poorly because of complex meta data and sync calls. > > We might use vmdk format or VHD as a base for the future high > performing, safe > image format for qemu You'll want to validate VHD carefully. I tested it just yesterday (with kvm-83), and "qemu-img convert" does not correctly unpack my VHD image (from Microsoft Virtual PC) to raw, compared with the unpacked version from MSVPC's own conversion tool. There's some patches which greatly improve the VHD support; I'm not sure if they're in kvm-83. -- Jamie