Re: kdump/kexec/crash on vmcore file

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

Hi, Vivek.  Thank you very much for the tips.  I went back to check my
command to load the crash/capture kernel and found out that I loaded
the wrong kernel.  I then tried again with the correct kernel and now
I was able to use crash to analyze the vmcore kdump file.

Thank you once again.

On 10/13/06, Vivek Goyal <vgoyal@in.ibm.com> wrote:
> On Thu, Oct 12, 2006 at 02:50:33PM -0700, Steven Truong wrote:
> > Hi, all.  This is my first attempt to troubleshoot a kernel panic so I
> > am quite newbie in this area. I have been able to obtain a kdump when
> > my box had kernel panic.
> >
> > I set up Kdump and Kexec and then the captured/crash kernel to boot
> > into Level 1 and then copy /proc/vmcore file to the disk for later
> > analysis.  However, after the server booted back to Level 3 and I
> > utilized the crash command to analyzed the vmcore file.  I got error
> > message:
> >
> > ./crash /boot/vmlinux ../vmcore.test
> >
> >
> > crash: read error: kernel virtual address: ffffffff8123d1e0  type:
> > "kernel_config_data"
> > WARNING: cannot read kernel_config_data
> > crash: read error: kernel virtual address: ffffffff813b5180  type: "xtime"
> >
>
> Hi Steven,
>
> which vmlinux are you using for analysis? First kernel's vmlinux or
> second kernel's vmlinux. You should be using first kernel's vmlinux.
>
> crash is trying to read some symbols from the core file and crash thinks
> that virtual address for kernel_config_data is ffffffff8123d1e0. I think
> this is too high a address. I guess this will be the address if you
> compile your kernel for physical address 16MB. So my first guess is that
> you are using second kernel's vmlinux for analysis.
>
> Which kernel version and kexec-tools version are you using?
>
> I am also copying the mail to crash-utility mailing list where folks
> keep a watch on crash related issues.
>
> Thanks
> Vivek
>