How to diagnose kernel panic?

[Mark Copper <mcopper@titaninterface.com>]

I have a server that is brought down by a kernel panic every two weeks
on average.  Nothing untoward gets in the logs and the on-screen panic
message starts with something like
   Kernel panic - not syncing: Fatal exception in interrupt
   
   Call trace:
   [<c026bc42>] scsi_request_fn+0xf610x294
I wasn't able to get any more at the data center...

So I brought the machine home and am running folding@home on it and so
far I have not been able to induce the panic.  The replacement machine
is similar, but not identical.  The main difference being a switch from
software to hardware RAID1.  Also, the new machine, except for the
hardware driver, uses stable while the problematic machine uses testing.
And the replacement has run so far without problem.

The only other thing I can add is that the bad machine would seem to
start getting "sluggish" before it froze, but for the life of me, I
couldn't see why.

I am posting because I'm hopeful that list participants might have
suggestions how I might start to chase down or, better yet, eliminate
this problem.

Is there a way, perhaps, to manufacture the possible interrupts that
occur?  

Thanks.

Mark