From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1L4iKE-0000y0-16 for qemu-devel@nongnu.org; Mon, 24 Nov 2008 15:46:30 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1L4iKA-0000wI-WC for qemu-devel@nongnu.org; Mon, 24 Nov 2008 15:46:29 -0500 Received: from [199.232.76.173] (port=54381 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1L4iKA-0000wB-MV for qemu-devel@nongnu.org; Mon, 24 Nov 2008 15:46:26 -0500 Received: from an-out-0708.google.com ([209.85.132.243]:20056) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1L4iKA-0006Kj-1S for qemu-devel@nongnu.org; Mon, 24 Nov 2008 15:46:26 -0500 Received: by an-out-0708.google.com with SMTP id c38so850916ana.37 for ; Mon, 24 Nov 2008 12:46:25 -0800 (PST) Message-ID: <492B129C.7070304@codemonkey.ws> Date: Mon, 24 Nov 2008 14:46:20 -0600 From: Anthony Liguori MIME-Version: 1.0 Subject: Re: [Qemu-devel] QCOW2 multiple disk (not VM) snapshots References: <492AB73B.8070201@suse.de> In-Reply-To: <492AB73B.8070201@suse.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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 Cc: msun@gatech.edu Kevin Wolf wrote: > Hi Mike, > > Mike Sun schrieb: > >> For a research project, we've been doing a bit of hacking with Xen and >> utilize QCOW disk images as our VBDs. One intriguing thing about the >> QCOW2 format was support for multiple disk snapshots. Unfortunately, >> it seems from what I've been able to glean that support for multiple >> snapshots within a QCOW2 image is really only supported by QEMU's VM >> snapshot feature. Since I'm using Xen and only use QCOW2 disk images, >> I was wondering if there was any way from a tool such as 'qemu-img' to >> take snapshots of the QCOW2 disk image only and not through the >> general QEMU VM snapshot? >> > > You can try the attached patch to qemu-img. I had it already for list, > delete and apply (as that's what I've needed so far), and I just added > create to it to make it complete. However, I didn't test it more than > making sure that it compiles and a new snapshot is listed afterwards. > > If you're interested in having real snapshots with Xen, i.e. basically a > combination of xm save/restore and qemu-img snapshot, I also have some > patches to do that. They have quite a few dependencies, though, so they > are not yet upstream. > Care to resubmit with a proper Signed-off-by line? Seems like a useful feature. Regards, Anthony Liguori > Kevin >