From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Storing command line options in qcow2 images Date: Wed, 08 Aug 2007 03:15:18 +0300 Message-ID: <46B90B16.7020604@qumranet.com> References: <59abf66e0707292040j11c8b981mf7f793258e874400@mail.gmail.com> <46B780E6.8050305@codemonkey.ws> <46B7F0A9.9060505@qumranet.com> <20070807135029.GA20274@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: "Daniel P. Berrange" Return-path: In-Reply-To: <20070807135029.GA20274-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Daniel P. Berrange wrote: > On Tue, Aug 07, 2007 at 07:10:17AM +0300, Avi Kivity wrote: > >> Anthony Liguori wrote: >> >>> I don't think adding annotations as snapshots is the right approach. I >>> think proper support should be added in the header. I wouldn't be too >>> concerned with breaking compatibility in qcow2. That's why it's qcow2 >>> and not just an updated version of qcow, qcow2 is still, AFAIK, open for >>> breakage. >>> >>> >> Are all the users' images open for breakage too? >> > > I'd say not. QCow2 has been around for a long time now so breaking compat > with existing images would be a very bad idea. Ideally though some extension > would be both backwards & forwards compatible - eg existing qcow2 impls > would just ignore any new extension, while new impls would work any image > with or without extension. If this isn't possible then at least call any > new format qcow3 to make it obvious to users that it is not compatible. > It was, of course, a rhetorical question. I initially suggested using a special snapshot as a means of preserving compatibility with qcow2, which I think is better than introducing yet a new format. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/