kexec/ kdump setup problem

[Sachin P. Sant]

Mrunal Gawade wrote:
> Hi,
>
> I just checked /sys/kernel/kexec_crash_loaded file after giving the 
> kexec -p command for loading panic kernel. And the value was 1. So it 
> was loaded successfully. I then crashed kernel and it hanged. I 
> rebooted manually and checked the value in the file again and it was 
> "0". So across reboot it got reset. So if I assume that the kernel 
> loading was successful, the question remains if it got loaded 
> successfully at the designated space 65M at 16M. How do I know that? 
The file /sys/kernel/kexec_crash_loaded will have value 1 if the kdump kernel has been
loaded successfully. In your case when you executed kexec -p the kernel was loaded at
the designated space and value 1 in kexec_crash_loaded reflects that. This value won't
be retained across reboots. One will have to again execute the kexec -p command to
load the kdump kernel after reboot. [ If kdump service is enabled (chkconfig kdump on)
kexec -p will get executed after every reboot. ]

I think in your case the problem is that after a successful load, the kdump kernel
does not boot on a system crash.[alt-sysrq-c]. you could try adding console
related options to the kexec command and see if that will give some information
on where the kernel hangs.

Thanks
-Sachin