From mboxrd@z Thu Jan 1 00:00:00 1970 From: 0bo0 <0.bugs.only.0@gmail.com> Subject: Re: trying to debug xen4 & qemu-dm, Xen reports "core dump failed" Date: Tue, 26 Jan 2010 14:47:38 -0800 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 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: Keir Fraser Cc: "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org On Tue, Jan 26, 2010 at 2:30 PM, Keir Fraser wrote: >>> 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. bash ulimit -c unlimited echo '/var/core/core.%e.%u.%p' > /proc/sys/kernel/core_pattern mkdir -p /var/core cat /proc/sys/kernel/core_pattern /var/core/core.%e.%u.%p service xend restart xm create /etc/xen/vm/test.cfg ls -al /var/core/ | grep core -rw------- 1 root root 4542464 2010-01-26 14:36 core.qemu-dm.0.7772 gdb /usr/lib64/xen/bin/qemu-dm /var/core/core.qemu-dm.0.7772 ... /usr/lib64/xen/bin/qemu-dm: Too many levels of symbolic links. Missing separate debuginfo for the main executable file Try: zypper install -C "debuginfo(build-id)=9326caa0db4accd719f10b02a9a41a40c10b662a" Core was generated by `/usr/lib/xen/bin/qemu-dm -d 4 -serial pty -domain-name test -videoram 4 -k en-u'. Program terminated with signal 11, Segmentation fault. #0 0x000000000047b974 in ?? () (gdb) quit zypper install -C "debuginfo(build-id)=9326caa0db4accd719f10b02a9a41a40c10b662a" Loading repository data... Reading installed packages... 'debuginfo(build-id)=9326caa0db4accd719f10b02a9a41a40c10b662a' not found. Resolving package dependencies... so where/how do I get the debug symbols?