From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=35257 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1ON3mF-00033r-DO for qemu-devel@nongnu.org; Fri, 11 Jun 2010 08:56:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1ON3mE-0001IM-0R for qemu-devel@nongnu.org; Fri, 11 Jun 2010 08:56:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40723) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1ON3mD-0001Hn-PJ for qemu-devel@nongnu.org; Fri, 11 Jun 2010 08:56:01 -0400 Date: Fri, 11 Jun 2010 09:55:48 -0300 From: Luiz Capitulino Subject: Re: [Qemu-devel] Re: KVM call minutes for June 8 Message-ID: <20100611095548.3d256bfb@redhat.com> In-Reply-To: <4C10F656.20305@codemonkey.ws> References: <20100608150500.GA28492@x200.localdomain> <4C0E694F.8040607@codemonkey.ws> <20100608175952.5f43ea8f@redhat.com> <4C0EB281.80907@codemonkey.ws> <20100609121820.1f3bb47a@redhat.com> <20100609153107.GE28326@redhat.com> <4C0FBFDF.5050009@codemonkey.ws> <4C10B3AF.5000201@redhat.com> <4C10E064.5090106@codemonkey.ws> <4C10E3B2.9070905@redhat.com> <4C10F656.20305@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: Kevin Wolf , Chris Wright , kvm-devel , armbru@redhat.com, qemu-devel@nongnu.org On Thu, 10 Jun 2010 09:27:34 -0500 Anthony Liguori wrote: > On 06/10/2010 08:08 AM, Kevin Wolf wrote: > > Am 10.06.2010 14:53, schrieb Anthony Liguori: > > > >> On 06/10/2010 04:43 AM, Kevin Wolf wrote: > >> > >>> Huh, why this? Seems I still haven't understood all of qcow2 then... I > >>> always thought that there's just a specific offset where VM state > >>> starts, but no explicit end. > >>> > >>> > >> A live snapshot can last for a very long time. What happens if you need > >> to allocate a new block for disk I/O while saving a snapshot? > >> > > You allocate it, I guess? > > > > Note that VM state must be virtually contiguous, but not necessarily > > physically (virtually = on the virtual hard disk as seen by the guest; > > physically = in the image file). It's just not seen by the guest because > > it's saved at a high offset that is after the end of the real disk > > content, but otherwise it should behave the same as guest data. > > > > I guess you could just start writing and then once your finished, you > could update the snapshot information. So yeah, I think your right that > it's doable with the current format. No more issues on having them in QMP for 0.13 then?