From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=52065 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PQG6T-0002xh-GJ for qemu-devel@nongnu.org; Wed, 08 Dec 2010 04:14:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PQG6S-0005ui-CK for qemu-devel@nongnu.org; Wed, 08 Dec 2010 04:14:25 -0500 Received: from mx1.redhat.com ([209.132.183.28]:16062) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PQG6S-0005ua-39 for qemu-devel@nongnu.org; Wed, 08 Dec 2010 04:14:24 -0500 Message-ID: <4CFF4C6C.70202@redhat.com> Date: Wed, 08 Dec 2010 10:14:20 +0100 From: Jes Sorensen MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH 1/1] qemu-img.c: Clean up handling of image size in img_create() References: <1291743586-3518-1-git-send-email-Jes.Sorensen@redhat.com> <4CFF47B0.1030906@redhat.com> In-Reply-To: <4CFF47B0.1030906@redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf Cc: Stefan Hajnoczi , qemu-devel@nongnu.org On 12/08/10 09:54, Kevin Wolf wrote: > Am 07.12.2010 21:36, schrieb Stefan Hajnoczi: >> Today it is possible to create 0 byte sized images. Your patch will >> change that: >> If there is a backing file, then the size will be taken from the backing file. >> If there is no backing file, then an error about missing size will be >> printed, even though a size of 0 has been given. > > I can think of one use case for it: You can store the VM state on a > zero-sized qcow2 image for internal snapshots. > > Otherwise it's probably rather useless, but we have supported it for a > long time, so I wouldn't remove it. People have actually noticed in the > past when something was broken with it. Ok that is fair, I have just posted an updated version which should do the right thing. Shows up it made the patch even simpler :) Cheers, Jes