From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: Storing command line options in qcow2 images Date: Tue, 07 Aug 2007 19:36:41 -0500 Message-ID: <46B91019.1020009@codemonkey.ws> References: <59abf66e0707292040j11c8b981mf7f793258e874400@mail.gmail.com> <46B780E6.8050305@codemonkey.ws> <46B7F0A9.9060505@qumranet.com> <20070807135029.GA20274@redhat.com> <46B90B16.7020604@qumranet.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: Avi Kivity Return-path: In-Reply-To: <46B90B16.7020604-atKUWr5tajBWk0Htik3J/w@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 Avi Kivity wrote: > 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. There are still more features I'd like to see added to qcow2 so I'm hoping that it's not frozen. For instance, copy-on-read would be very useful. Regards, Anthony Liguori > > ------------------------------------------------------------------------- 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/