From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keir Fraser Subject: Re: trying to debug xen4 & qemu-dm, Xen reports "core dump failed" Date: Tue, 26 Jan 2010 22:30:18 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: 0bo0 <0.bugs.only.0@gmail.com> Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On 26/01/2010 22:12, "0bo0" <0.bugs.only.0@gmail.com> wrote: > On Tue, Jan 26, 2010 at 1:38 PM, Keir Fraser > wrote: >> As root: >> echo '/var/core/core.%e.%u.%p' > /proc/sys/kernel/core_pattern >> >> Now try starting your guest. It fails, and hopefully you have a core file in >> /var/core/. You can load it into gdb as 'gdb /usr/lib/xen/qemu-dm >> /var/core/name-of-core-file' and then execute bt command at the gdb prompt. >> That hopefully tells us where qemu-dm crashed. > > bash > ulimit -c unlimited Actually that probably only enable core dumps for the shell you are running. Qemu-dm will inherit its ulimits from xend. So you need to enable core dumps by running 'ulimit -c unlimited' before you start xend, or put it in the startup script that starts xend. You could also script the echo to /proc/sys/kernel/core_pattern, but it's definitely safe to do that later from a shall, as it's a global value, rather than per-process. -- Keir