How To Create a Panic?

[carl_...@hotmail.com]

We have panic woes and too much memory to save a dump in swap. Later
today we will mount a new disk and leave a raw partition which will
become the default dump device. I am putting together a procedure for
on-site operators to save the image when the system panics. I want to
test my procedure on another very similar system. How can I induce a
panic that will write to this default dump area? Any other ideas or
suggestions?

Details:
SCO OSR 5.0.4
2 gig RAM

Thanks lots to everybody!

Carl S.

PS - Don't tell me to "Shout FIRE in a crowded theater"!! (It's a
joke, son.)

[Jean-Pierre Radley]

carl_...@hotmail.com propounded (on Sun, Feb 10, 2002 at 10:40:49PM +0000):
| How can I induce a panic ... ?

| Details:
| SCO OSR 5.0.4
| 2 gig RAM

Have you tried TA 103679?

--
JP

[carl_...@hotmail.com]

On Sun, 10 Feb 2002 23:13:25 GMT, Jean-Pierre Radley <j...@jpr.com>
wrote:

I did not find this TA when I went searching. You are always there
for me, JP. Thanks Much!
C

[Bela Lubkin]

Carl Sawyer

> We have panic woes and too much memory to save a dump in swap. Later
> today we will mount a new disk and leave a raw partition which will
> become the default dump device. I am putting together a procedure for
> on-site operators to save the image when the system panics. I want to
> test my procedure on another very similar system. How can I induce a
> panic that will write to this default dump area? Any other ideas or
> suggestions?
>
> Details:
> SCO OSR 5.0.4
> 2 gig RAM

Add the following to the end of /etc/conf/node.d/mm:

=============================================================================
# The following devices are not normally enabled.
#
# /dev/io[bwl] provide byte, word and longword access to I/O space. The
# semantics may be somewhat unexpected, as the kernel automatically
# seeks forward after I/O. For best results, always lseek() the desired
# address before reading/writing. Access must be restricted as these
# devices can be used to crash the system, take it over, or worse.
#
# /dev/panic causes a deliberate kernel panic when read from or written
# to.
#
# mm iob c 3 root sys 600
# mm iow c 4 root sys 600
# mm iol c 5 root sys 600
# mm panic c 6 root sys 600
=============================================================================

If you uncomment (remove the "# " from) the lines that start with
"# mm", then relink the kernel, /dev/panic will be created. Reading or
writing that device panics the system. (Only root can open it.)

The other devices provide access to I/O device space, might be useful
for programmers. /dev/io[bwl] apply to releases back to SCO Unix 3.2.0,
probably also SCO Xenix. /dev/panic applies to OpenServer 5.0.4 and
later.

Meanwhile, you might find this useful. You can deliberately boot your
system with less RAM than is physically present. Run `divvy /dev/swap`
and see how big swap is. Convert to megabytes. Then reboot and, at the
boot prompt, enter:

Boot
: defbootstr mem=1m-256m

Replace "256" with the actual size of swap, in megabytes. You might
want to err a bit on the small side to avoid arithmetic errors due to
the mass confusion about what a megabyte is.

Once booted this way, a panic should successfully write a dump to swap.
Of course this is only helpful if your swap is big enough for the system
to work with that little RAM...

>Bela<