32.3. Analyzing the Core Dump
To determine the cause of the system crash, you can use the crash utility, which provides an interactive prompt very similar to the GNU Debugger (GDB). This utility allows you to interactively analyze a running Linux system as well as a core dump created by
netdump, diskdump, xendump, or kdump.
Important
To analyze the
vmcore dump file, you must have the crash and kernel-debuginfo packages installed. To install the crash package in your system, type the following at a shell prompt as root:
yum install crash
To install the kernel-debuginfo package, make sure that you have the yum-utils package installed and run the following command as
root:
debuginfo-install kernel
Note that in order to use this command, you need to have access to the repository with debugging packages. If your system is registered with Red Hat Subscription Management, enable the
rhel-6-variant-debug-rpms repository as described in Section 8.4.4, “Viewing the Current Configuration”. If your system is registered with RHN Classic, subscribe the system to the rhel-architecture-variant-6-debuginfo channel as documented here: https://access.redhat.com/site/solutions/9907.
32.3.1. Running the crash Utility
To start the utility, type the command in the following form at a shell prompt:
crash/usr/lib/debug/lib/modules/kernel/vmlinux/var/crash/timestamp/vmcore
Note that the kernel version should be the same that was captured by
kdump. To find out which kernel you are currently running, use the uname -r command.
Example 32.2. Running the crash utility
~]#crash /usr/lib/debug/lib/modules/2.6.32-69.el6.i686/vmlinux \/var/crash/127.0.0.1-2010-08-25-08:45:02/vmcorecrash 5.0.0-23.el6 Copyright (C) 2002-2010 Red Hat, Inc. Copyright (C) 2004, 2005, 2006 IBM Corporation Copyright (C) 1999-2006 Hewlett-Packard Co Copyright (C) 2005, 2006 Fujitsu Limited Copyright (C) 2006, 2007 VA Linux Systems Japan K.K. Copyright (C) 2005 NEC Corporation Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc. Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc. This program is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Enter "help copying" to see the conditions. This program has absolutely no warranty. Enter "help warranty" for details. GNU gdb (GDB) 7.0 Copyright (C) 2009 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "i686-pc-linux-gnu"... KERNEL: /usr/lib/debug/lib/modules/2.6.32-69.el6.i686/vmlinux DUMPFILE: /var/crash/127.0.0.1-2010-08-25-08:45:02/vmcore [PARTIAL DUMP] CPUS: 4 DATE: Wed Aug 25 08:44:47 2010 UPTIME: 00:09:02 LOAD AVERAGE: 0.00, 0.01, 0.00 TASKS: 140 NODENAME: hp-dl320g5-02.lab.bos.redhat.com RELEASE: 2.6.32-69.el6.i686 VERSION: #1 SMP Tue Aug 24 10:31:45 EDT 2010 MACHINE: i686 (2394 Mhz) MEMORY: 8 GB PANIC: "Oops: 0002 [#1] SMP " (check log for details) PID: 5591 COMMAND: "bash" TASK: f196d560 [THREAD_INFO: ef4da000] CPU: 2 STATE: TASK_RUNNING (PANIC) crash>
