Re: HARDWARE HELL - POSSIBLE LINUX BUG AND/OR HARDWARE FAILURE ?

[Theodore Y. Ts'o]

Something that you might want to do is to check the temperature of
various parts of your system on the motherboard.  There have been cases
where memory that's been certified by a major CPU manufacturer as being
Good Stuff was, when run under a really good memory torture test
(written by Larry Augustine), was observed to reach surface temperatures
of over 90 degrees centigrade.  (And this was in an otherwise well
ventilated chasis!)  The guess is that it worked fine in Windows sytems,
because it never agressively accessed the memory that hard, so the
manufacturer never noticed the fundamental design flaw.  Obviously, we
decided not to use that particular memory in our systems.  :-)

Given that your problems started (and restarted) when you ran GNU shred,
I would suggest running it, and then when your system crashes, take some
temperature measurements and see if anything seems unusually hot.  From
your description, it sounds suspiciously like a thermal problem.  Do the
problems seem to go away (or lessen) if you let the computer cool down
for a while?

If you have some temperature probes, try attaching them to various parts
of the motherboard (especially the CPU, memory, and cache), and then run
your system with the cover on.  The problem may also be exacerbated by a
bad chasis design so that there are "hot spots" in certain parts of your
motherboard.  Then, when a program agressively exercises the system,
it's enough to cause some component (probably memory or cache, given
your symptoms) to fall over.  Oh, I'd also put a thermal sensor on your
disk drive; some disk drives can get *really* hot when you exercise them
a lot.  (The Seagate Barracudas come to mind as a good example.)

Finally, I'll give a plug for VA Linux's "burn-in" software, which can
be found at "ftp://ftp.valinux.com/pub/software/Cerberos".  You might
find it a good way to torture test a system (sometimes to failure, if
it's dodgy on ventilation, power, etc.; read the warnings before you use
it.)

						- Ted