Date: Tue, 16 Sep 2003 16:13:17 +0200
From: Stephan von Krawczynski <skraw@ithnet.com>
To: root@chaos.analogic.com
Cc: marcelo.tosatti@cyclades.com.br, neilb@cse.unsw.edu.au,
       linux-kernel@vger.kernel.org
Subject: Re: experiences beyond 4 GB RAM with 2.4.22
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On Tue, 16 Sep 2003 09:55:36 -0400 (EDT)
"Richard B. Johnson" <root@chaos.analogic.com> wrote:

> Can you explain what you mean by "network connections go bogus".

Sure. Do this:

Use a controller (like 3ware) that cannot DMA beyond a 4 GB range. Now put some
GBs of data onto that and start to tar the data around on the same disk. While
doing this you can watch network go crazy and drop packets at will. You can of
course force the whole setup further by (trying) additional nfs-action, but
this is really not needed.
Just about the same thing can be experienced if you do a simple find all over
the disk. CPU load explodes and network is _dead_.
To try this you need some GBs of data, a box with more than 4 GB ram, 3ware
controller and a usual SuSE 8.2. Wait until after midnight for "updatedb" to
run and try to login during that time ;-)
"Works" with out-of-the-box equipment and distro :-)

Regards,
Stephan
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