Re: Linux Kernel Dump Summit 2005

[Carsten Otte <cotte@de.ibm.com>]

Andrew Morton wrote:
> I was rather expecting that the various groups which are interested in
> crash dumping would converge around kdump once it was merged.  But it seems
> that this is not the case and that work continues on other strategies.
> 
> Is that a correct impression?  If so, what shortcoming(s) in kdump are
> causing people to be reluctant to use it?
On 390, we have standalone dump. That is a tool you can install on a disk
with zipl (like lilo) and that you boot when your server has crashed.
Newer machines also have a hardware feature built-in that does this from the
service element (that is a laptop computer mounted to the big box).
When running on z/VM, there is a command you can enter on z/VM's console
which causes z/VM to create a dump of Linux' memory.
Different from kdump we can even take a dump if our system is so badly
corrupted that you don't even get a panic message. As far as I know, kdump
would require to reserve memory for the extra kernel prior to crash, which
is not the case with our soloutions.
-- 

Carsten Otte
IBM Linux technology center
ARCH=s390