From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1LZECh-0006bv-6X for qemu-devel@nongnu.org; Mon, 16 Feb 2009 19:52:51 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1LZECf-0006bA-Fg for qemu-devel@nongnu.org; Mon, 16 Feb 2009 19:52:50 -0500 Received: from [199.232.76.173] (port=38843 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1LZECf-0006b1-7V for qemu-devel@nongnu.org; Mon, 16 Feb 2009 19:52:49 -0500 Received: from mail2.shareable.org ([80.68.89.115]:43035) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1LZECe-0002LG-N9 for qemu-devel@nongnu.org; Mon, 16 Feb 2009 19:52:48 -0500 Date: Tue, 17 Feb 2009 00:52:44 +0000 From: Jamie Lokier Subject: Re: [Qemu-devel] [PATCH] Revert block-qcow2.c to kvm-72 version due to corruption reports Message-ID: <20090217005244.GD20713@shareable.org> References: <20090213163043.GJ18471@shareable.org> <4995A723.9010208@codemonkey.ws> <20090213190419.GB20328@shareable.org> <4997502D.1080401@codemonkey.ws> <20090215020126.GA9281@shareable.org> <20090215154207.GA24821@shareable.org> <49985CB7.4090803@codemonkey.ws> <4998BB06.1020306@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4998BB06.1020306@codemonkey.ws> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Anthony Liguori wrote: > >>And let's be clear, your data is *not* safe with qcow2. So I don't > >>consider this to be a show stopping issue. > > > >I beg your pardon? The one format that was recommended for quite a long > >time now is considered unsafe? > > It's always been that way. It's unsafe for a number of reasons that > have been discussed at great length. It sure isn't mentioned in the documentation. If it was, I would never have used it, and I imagine I'm not alone. QEMU might be an emulator project where people expect quirks, but KVM and Xen are professional virtualisation platforms competing with VMware. It is really not very professional that the documentation places "your data is not safe" formats on an equal footing with safe formats - without saying anything about it - and doesn't even recommend one or the other. That said, maybe Microsoft is doing the same thing - their documentation happily recommends their VHD format if you're not concerned about running out of disk space, and it's maybe VHD has similar corruption windows. -- Jamie