From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Clemens Subject: Re: User feedback Date: Fri, 05 Oct 2007 10:57:15 -0400 Message-ID: <1191596235.24957.18.camel@beth> References: <84ad660e0710050502q3f4a3156g5451f7c70f2f7fdd@mail.gmail.com> <47063371.9060105@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org To: Anthony Liguori Return-path: In-Reply-To: <47063371.9060105-rdkfGonbjUSkNkDKm+mE6A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Fri, 2007-10-05 at 07:52 -0500, Anthony Liguori wrote: > http://hg.codemonkey.ws/qemu-nbd/ > > This will let you expose a qcow file (or an individual partition within > a qcow file) as an NBD server which you can then mount on your host. A > bit round-about but it gets the job done. You just made my day. I've been threatening to do the same thing for weeks :) A couple of questions if you don't mind: - I was a bit confused by the statement on the nbd homepage: "Read-write nbd with client and server on same machine has a rather fundamental problem: when the system is short of memory, it tries to write back dirty pages. So the nbd client asks the nbd server to write back data, but as nbd-server is a userland process, it may require creating dirty pages to fullfill the request." The above makes sense, and the README in the source says this is not a problem on SMP systems since there's more than one kblockd flush thread... which makes less sense (why can't both kblockd's be blocked in this way?) Does qemu-nbd address this, perhaps by opening the qcow file with O_SYNC or something? or is this still a problem? - There's no license file with the code, I'm assuming it's GPL since you use qemu code directly? Thanks for writing such a useful bit of software! john.c ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/