From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamie Lokier Subject: Re: [Qemu-devel] Re: qcow2 corruption observed, fixed by reverting old change Date: Sun, 15 Feb 2009 02:27:19 +0000 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 Cc: Marc Bevand , qemu-devel@nongnu.org, Gleb Natapov , kvm@vger.kernel.org To: Dor Laor Return-path: Received: from mail2.shareable.org ([80.68.89.115]:55317 "EHLO mail2.shareable.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752717AbZBOC10 (ORCPT ); Sat, 14 Feb 2009 21:27:26 -0500 Content-Disposition: inline In-Reply-To: <499745A1.3040707@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: 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