From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1GuBhy-0003Hq-40 for qemu-devel@nongnu.org; Tue, 12 Dec 2006 12:46:26 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1GuBhw-0003Gq-FS for qemu-devel@nongnu.org; Tue, 12 Dec 2006 12:46:25 -0500 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1GuBhw-0003Gk-AZ for qemu-devel@nongnu.org; Tue, 12 Dec 2006 12:46:24 -0500 Received: from [131.111.8.130] (helo=ppsw-0.csi.cam.ac.uk) by monty-python.gnu.org with esmtp (Exim 4.52) id 1GuBhw-0001Ob-7v for qemu-devel@nongnu.org; Tue, 12 Dec 2006 12:46:24 -0500 From: Mark Williamson Subject: Re: [Qemu-devel] Re: NBD server for QEMU images Date: Tue, 12 Dec 2006 17:45:29 +0000 References: <20061212124803.47702.qmail@web52708.mail.yahoo.com> <200612121658.34017.paul@codesourcery.com> <20061212171340.GA24143@nevyn.them.org> In-Reply-To: <20061212171340.GA24143@nevyn.them.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200612121745.29305.mark.williamson@cl.cam.ac.uk> Sender: "M.A. Williamson" 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: Salvador Fandino > > > It's mostly intended to be used for accessing the files inside QEMU > > > disk images locally, without having to launch a virtual machine and > > > accessing then from there. > > > > mount -o loop does this. > > How is everybody missing the point? :-) mount -o loop doesn't mount > qcow images. Using dm-userspace (a device mapper with mappings generated by a userspace daemon instead of a kernel module) I believe it is possible to mount all kinds of weird and wonderful things - including things like qcow. The patches for dm-userspace are floating around, I think on the device mapper and Xen developer's mailing lists. Of course, this is a Linux-specific solution so an NBD server is probably still useful (can other OSes mount NBD? I assume so...?). In principle, you could use the NDB server to host storage for physical machines too, right? For instance you could opt for a fairly "thin" setup where all user disks are stored separately in qcow format to save space. This might be nice for some users of centralised storage systems... Cheers, Mark -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel!