HI everyone,

I'm trying to look into kernel core dump,

the core dump is placed in /var/crash

to use kdump it needs vmlinux in centos coud not find it also there is no directory debug as suggested in one of links

crash /usr/lib/debug/lib/modules/crashed-kernel-version/vmlinux /path-to-the-vmcore

Do i need to make a fresh kernel code compilation with debug mode set on? or can i download from any source the vmlinux for i386.

I could see in boot directory vmlinz can i generate the vmlinux is both same.

Please provide your valuable inputs
Thanks
Santosh

You need a debuginfo kernel equivalent to your running kernel (uname -r) - and the common. With luck you'll find it already built for you at debuginfo.centos.org - I did when I needed one on an older system
A quick google found this - seems worth a look.

1 members found this post helpful.

Thanks for that info, the link helped for installing the kernel-debug's

well i'm facing issue, not matching version with my vmcore.


[root@12]# crash /usr/lib/debug/lib/modules/2.6.18-128.el5.centos.plus/vmlinux /var/crash/2010-06-03-12\:47/vmcore

The following error i'm facing,

----
CRASHTIME=1275549346
cannot determine relocation value: not a live system
gdb /usr/lib/debug/lib/modules/2.6.18-128.el5.centos.plus/vmlinux
GNU gdb 6.1
Copyright 2004 Free Software Foundation, Inc.
GDB 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.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "i686-pc-linux-gnu"...

cpu_possible_map:
cpu_present_map: 3 12 13 16 17 22 30 31
cpu_online_map: 1 2 3 5 6 7 8 11 12 13 16 17 18 19 21 22 30 31
crash: cannot determine base kernel version
linux_banner:
��b���b���b���b
crash: /usr/lib/debug/lib/modules/2.6.18-128.el5.centos.plus/vmlinux and /var/crash/2010-06-03-12:47/vmcore do not match!

!
---

Verified the core image's linux version as below, moreover i'm using the same host for analysis where the core is dumped.

[root@localhost 2010-06-03-12:47]# strings vmcore | grep "Linux version"
Linux version 2.6.18-128.el5PAE (mockbuild@builder16.centos.org) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-44)) #1 SMP Wed Jan 21 11:19:46 EST 2009

Following is the rpm list have installed.

[root@localhost ~]# rpm -qa | grep -i kernel.*debug
kernel-debug-devel-2.6.18-128.1.6.el5
kernel-debuginfo-2.6.18-128.el5.centos.plus
kernel-debug-2.6.18-128.1.6.el5
kernel-debuginfo-common-2.6.18-128.el5.centos.plus
kernel-PAE-debuginfo-2.6.18-128.el5.centos.plus
[root@localhost ~]#

Please help with your inputs am in correct path of analysis or anything i'm missing ?

- Santosh

Why aren't you using the PAE debuginfo ?.