From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Wolf Subject: Re: [Qemu-devel] qcow2 corruption observed, fixed by reverting old change Date: Mon, 16 Feb 2009 13:44:20 +0100 Message-ID: <49995FA4.3070508@suse.de> References: <20090211070049.GA27821@shareable.org> <4992A108.8070304@suse.de> <20090211114126.GC31997@shareable.org> <4992C77D.4030104@suse.de> <20090211164814.GA7161@shareable.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Laurent Vivier , kvm-devel To: qemu-devel@nongnu.org Return-path: Received: from ns.suse.de ([195.135.220.2]:40684 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754909AbZBPMhB (ORCPT ); Mon, 16 Feb 2009 07:37:01 -0500 In-Reply-To: <20090211164814.GA7161@shareable.org> Sender: kvm-owner@vger.kernel.org List-ID: Jamie Lokier schrieb: > Kevin Wolf wrote: >> Besides reviewing the code over and over again, I think the only real >> chance is that you can get a non-productive copy of your image and add >> some debug code so that we can see at least which code path is causing >> problems. > > I have a copy of my image to reproduce the bug, so I can test patches > including diagnostic patches. That's what I did to narrow it down. > > Being a company mail server, I can't send you the image of course. I perfectly understand that, it just makes debugging hard when you don't have a specific suspicion nor the problematic image. Do you need those diagnostic patches from me or will you try to put debug messages into the code yourself? I would just start putting in random printfs into alloc_cluster_offset() and the functions it calls to get some information about the failing write. I guess we'd need some iterations with my diagnostic patch and it wouldn't be any better than ad-hoc hacks done by yourself. >> By the way and completely off-topic: Have you already tried to use the >> VHD patches? I would really like to know if they fix your problems. > > Are those patches in kvm-83? I still have the image that was causing > problems way back, and I'm converting it to raw now with kvm-83 to see > if it now matches the raw image produced by VPC's own tool. Avi mentioned the patches in the kvm-84 announcement yesterday, so it seems they are not in kvm-83. Kevin