From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by monty-python.gnu.org with tmda-scanned (Exim 4.20) id 19Xe7C-0004G8-48 for qemu-devel@nongnu.org; Wed, 02 Jul 2003 05:41:26 -0400 Received: from mail by monty-python.gnu.org with spam-scanned (Exim 4.20) id 19Xe70-00043g-OS for qemu-devel@nongnu.org; Wed, 02 Jul 2003 05:41:18 -0400 Received: from smtp4.wanadoo.fr ([193.252.22.26] helo=mwinf0501.wanadoo.fr) by monty-python.gnu.org with esmtp (Exim 4.20) id 19Xe5O-0003Sc-2U for qemu-devel@nongnu.org; Wed, 02 Jul 2003 05:39:34 -0400 Message-ID: <3F02AA9D.1030307@free.fr> Date: Wed, 02 Jul 2003 11:49:17 +0200 From: Fabrice Bellard MIME-Version: 1.0 References: <20030702065122.0DAD72C0D3@lists.samba.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH] Snapshot block device support Reply-To: qemu-devel@nongnu.org List-Id: List-Help: List-Post: List-Subscribe: , List-Archive: List-Unsubscribe: , To: Rusty Russell Cc: qemu-devel@nongnu.org I had plans to implement "copy on write" disk images...I find your approach original. My initial plan was just to add a second disk image for each disk containing the changes. It should be easy to do it from your code (for example by adding options '-hdacow file' where file is the snapshot file you use). About IDE, it is working (at least with kernel 2.4.20). Someone has even compiled a linux kernel inside QEMU (slowdown factor of about 15), so vl begins to be usable for real tasks. There are still known problems if several processes use floating point at the same time. Fabrice. Rusty Russell wrote: > Hi Fabrice, > > I haven't got the IDE emulation to work for me yet (is it > supposed to yet?), but this allows the "-snapshot" option and "C-a s" > to commit the disks. The blocks which change are committed to backing > store, and a bitmap of changed blocks is kept. > > Diff + new test file below. > Rusty.