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	Sun, 15 Jun 1997 12:34:17 -0500 (EST)
From: "John S. Dyson" <toor@dyson.iquest.net>
Message-Id: <199706151734.MAA00300@dyson.iquest.net>
Subject: Re: Reasonable diagnosis?
In-Reply-To: <Pine.BSI.3.96.970615110245.11599B-100000@pompano.pcola.gulf.net> from Nick Johnson at "Jun 15, 97 11:11:46 am"
To: spatula@gulf.net (Nick Johnson)
Date: Sun, 15 Jun 1997 12:34:17 -0500 (EST)
Cc: freebsd-questions@FreeBSD.ORG
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> 
>    My analysis of these events leads me to believe that most of my
> problems are the result of a flaky disk controller; the page faults could
> very well have been a result of reading bad data off the swap partition on
> the disk, which could conceivably make the OS go berzerk, resulting in any
> number of strange things happening, such as the video spasm I got last
> night (which had also happened a few months ago before either partition
> crashed.  at that time it looked like a program mistakenly thought its
> stack belonged in my video ram).
> 
>    The disk controller is a WDC AC31600H on a WD Caviar drive.  I've been
> told that the WD controllers beginning with a 3 cause problems.  Can
> anyone share experiences of this?
> 
>    Any insight or corrections to my hypothesis are most welcome and
> appreciated.
>   
Not regarding the drive, but regarding the kernel...  If ANY swapping
occurs, the upages can be corrupted, the kernel will likely crash.
In essence, if you have a system that SIG-11's at all due to hardware
problems, your system will be much more vulnerable if you swap.

John