[RFC] Kdump: Dump Capture Mechanism

From: Vivek Goyal
Date: Wed Mar 09 2005 - 01:46:06 EST


Well this discussion has been going on for quite sometime now that
what's the best way to capture the dump? There seems to be two lines of

Export ELF view through /proc/vmcore
This basically involves retrieving saved core image headers and
exporting those through /proc/vmcore interface. Further user space
applications can be built on top of it to do advanced processing.

Do Everything in user space
The whole idea is that do all the processing from user space (preferably
from ramdisk or so).

When it comes to requirements, Distros and developers seem to be having
somewhat different requirements.

- Fully automate the dump generation/capture process.
- Configure everything in advance (like, dump storage location).
- Upon crash, store dump image at pre-configured location and reboot
into production kernel ASAP.

- Keyword is simple and easy to use solution.
- Should work well in a development environment where, not necessarily
all the components (user space, kernel space) are in perfect harmony
and things are yet to be stabilized.

IMO, exporting /proc/vmcore is a good idea. It offers wide variety of
choices to both developers and distros.

- It provides the basic dump capturing mechanism in kernel.

- Developers can store the dump image locally (cp) or transfer it over
network (scp, ftp) using standard utilities and don't have to deal
with additional user space utilites specifically designed for this

- Developers can directly run gdb on /proc/vmcore generated image and
do the limited debugging without need of any other dump
capture/analysis utility.

- Distros can build additional fully automated dump saving solutions on
top of /proc/vmcore. Be it a init script or a custom initial ramdisk
or something else.......

So the whole idea is, that /proc/vmcore and user space solutions can co-
exist. And let the user/distros choose between these based on their

I was planning to implement /proc/vmcore. Do you have any comments or


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