kdump not writing any vmcore

Neil Horman nhorman at redhat.com
Fri Feb 12 10:57:55 EST 2010

On Fri, Feb 12, 2010 at 03:42:20PM +0100, Gallus wrote:
> On 11 February 2010 19:06, Neil Horman <nhorman at redhat.com> wrote:
> > On Thu, Feb 11, 2010 at 05:26:50PM +0100, Gallus wrote:
> >
> > > Does someone have any experience with such problems? Is there
> > > something left to try out?
> > >
> > Yes, this is what I fix all the time.  despite your comments above, a console
> > log would still be helpful.  It will give us the bet pointer to whats going
> > wrong.
> > Neil
> Can you share some thoughts about such problems? Any suggestion may be helpful.
> Gallus

I can, but its just blind guessing until you provide details of the error
(preferably in the form of a log file from the time the kdump kernel booted).

It could be that the kernel has a legitimate bug that it encounters during boot
up, and never makes it to the initramfs.  That would be evident if the end of a
console log showed a panic with a backtrace

It could be that your nic driver isn't initalizing the ethernet card properly,
and you're not sending frames, so you can't establish a connection to your
ftp/ssh/nfs/etc server.  A console log would show dhcp or other network errors
in this case

It could be that the kernel was unable to parse the elf headers that kexec wrote
into the kernel before the crash, and as such, can't deliver the core to any
user space apps for reconding, this would show up as write errors on the

The list goes on.  But the central theme is that we can't diagnose it without at
minimum a console log.


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