From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:48458) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QFmXr-0006N5-6u for qemu-devel@nongnu.org; Fri, 29 Apr 2011 08:11:40 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QFmXq-0001Gu-9h for qemu-devel@nongnu.org; Fri, 29 Apr 2011 08:11:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39513) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QFmXp-0001Gq-Vq for qemu-devel@nongnu.org; Fri, 29 Apr 2011 08:11:38 -0400 Message-ID: <4DBAAB92.1040700@redhat.com> Date: Fri, 29 Apr 2011 14:14:10 +0200 From: Kevin Wolf MIME-Version: 1.0 References: <1303910855-28999-1-git-send-email-stefanha@linux.vnet.ibm.com> <1303910855-28999-4-git-send-email-stefanha@linux.vnet.ibm.com> In-Reply-To: <1303910855-28999-4-git-send-email-stefanha@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 3/8] qed: add support for Copy-on-Read List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: Anthony Liguori , qemu-devel@nongnu.org Am 27.04.2011 15:27, schrieb Stefan Hajnoczi: > From: Anthony Liguori > > When creating an image using qemu-img, just pass '-o copy_on_read' and then > whenever QED reads from a backing file, it will write the block to the QED > file after the read completes ensuring that you only fetch from the backing > device once. As discussed previously, this is not the right primary interface. Also, the patch still seems to be broken with respect to concurrent writes. Kevin