kexec / kdump kernel panic

["Steven Truong" <midair77@gmail.com>]

Hi, I have a dual Xeon 3.2 GHz with Cent OS 4.3 and this box is in a
cluster. It keeps bailling out with kernel panic type of error and I
can not determine for sure what type of kernel or hardware problem. I
have tried to play with kexec and kdump with the hope to set up and
capture the kernel dump to debug.

I have followed the instruction in linux-2.16.18
Documentation/kdump/kdump.txt closely but still have not been able to
get it to work for loading the caputured kernel for panic kernel
situation.

I have the system kernel with Linux 2.16.18 booted up and set with
crashkernel=128M@16M. I compiled this system kernel with KEXEC, SYSFS,
DEBUG_INFO and CRASH_DUMP enabled. When this box is up with this
system kernel and can see that the total memory is 128 MB less than
the physical memory.

For the crash/captured kernel, I had SMP disable and KEXEC,
CRASH_DUMP, and VMCORE enabled.  PHYSICAL_START=0x1000000.

I first tested with the following command and saw that the
crash/captured kernel booted up the box without going through the BIOS
initialization.

/usr/sbin/kexec -l /boot/vmlinux
--initrd=/boot/initrd-2.6.18-kdump.img --args-linux
--append="root=/dev/sda3  init  1"

However, when I tried to load the crash/captured kernel for kernel
panic situation, I just got failed to load kernel /boot/vmlinux error
message. I used the following command to load :

/usr/sbin/kexec -p /boot/vmlinux
--initrd=/boot/initrd-2.6.18-kdump.img --args-linux
--append="root=/dev/sda3  irqpoll init 1"

I did make sure that vmlinux is not a bzImage file by using this command

readelf -h /boot/vmlinux

and I was able to see the output of this command. If I used this one
with bzImage file, I won't see anything. So I am pretty sure the
kernel file vmlinux is ok.

I did strace the second command but did not gain any special knowledge
here and no error message could be found in any log files.

I used kexec-tools-1.101 and kexec-tools-1.101-kdump10.patch.