From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53973) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VcAuY-00072P-Gm for qemu-devel@nongnu.org; Fri, 01 Nov 2013 05:21:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VcAuS-0000cq-HY for qemu-devel@nongnu.org; Fri, 01 Nov 2013 05:20:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:62994) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VcAuS-0000bu-1o for qemu-devel@nongnu.org; Fri, 01 Nov 2013 05:20:52 -0400 Date: Fri, 1 Nov 2013 10:20:45 +0100 From: Stefan Hajnoczi Message-ID: <20131101092045.GA17709@stefanha-thinkpad.redhat.com> References: <201311010604.19768.hahn@univention.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201311010604.19768.hahn@univention.de> Subject: Re: [Qemu-devel] VHD suport in QEMU? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philipp Hahn Cc: kwolf@redhat.com, Jeff Cody , qemu-devel@nongnu.org, xen-devel@lists.xen.org On Fri, Nov 01, 2013 at 06:04:19AM +0100, Philipp Hahn wrote: > sorry for high-jacking this thread, but I have a questing regarding VHD (without the X): Xen-4.3 switched to upstream QEMUs support for VHD. The dropped their own VHD implementation in blktap2, which supported backing chains, which QEMU currently doesn't. The Xen implementation (xen/tools/blktap2/vhd/lib/ is BSD 3 clause) also supports some kind of journal. > 1. Does someone know if the journal support for VHD is somehow related to VHDX? > 2. Has somewone put some work into supporting backing chains? I started to have a look myself some time ago, but had to do other work since then. Hi Philipp, I'm not aware of block/vpc.c (classic VHD) improvements at this time. Out of interest, are the VHD Differencing images you'd like to use come from Xen, VirtualPC, or something else? Stefan