Subject: Re: Physical memory tests?
To: Jonathan Stone <jonathan@DSG.Stanford.EDU>
From: Luke Mewburn <>
List: port-i386
Date: 08/05/1996 10:52:42
Jonathan Stone writes:
> Is there a NetBSD/i386 memory-tester that can run at boot?  If so, how
> can I enable it?  I want to do this on machines that're installed as
> routers.  Booting into DOS to do a check isn't really an option; the
> machines are in wiring closets.

I found that even stuff like checkit wouldn't find dodgy memory in one
of my machines (that I *know* had bad memory - the machine just needed
to run for a day or two and once it had heated up long enough and
programs would start up and start paging, it would crash at random

The most sure-fire way I found to detect dodgy memory was to run, of
all things, a Linux install disk that uses a ram disk for installation
and compressed kernel image. I learnt this trick from a linux-using
friend, and I have a such a disk just for this purpose. If I want to
rule out the memory, I boot the disk.

As much as this doesn't seem feasable, there *does* appear to be
something about the way that the ram disk image is built and the way
the kernel is uncompressed that will trigger a memory fault if your
memory 'in the middle' of the address range is dodgy. 

I'm sure someone has an explanation...