fixed disk error

[Mark Dornfeld]

In article <497 at scovert> stephm at sco.COM (Stephen P. Marr) writes:
>romwa at gpu.utcs.toronto.edu (Mark Dornfeld) writes:
>>
><...>Can anyone help with this Xenix error message?
>>
>>error on fixed disk (minor 40), block=16544
>>Error Type 0, Code 3, Unit 0
>>Write/Drive Fault
>>
>><...>
>>
>>Mark T. Dornfeld
>>
>><...>
>>
>>mark at utgpu!rom      - or -     romwa at utgpu
>
>A Write/Drive Fault means that the controller went bye-bye.
>I'm responsible for running some 35+ machines here at SCO,
>and I've seen this error on two machines in the last 2.5 years.
>
I've gotten some good advice on this problem and in general
everybody's experience is with a bad controller or disk.

But here's an update:  I noticed a pattern of the times of the
bad writes and all except two of them occur between 9 and 10
AM and between 5 and 7 PM.  This machine is in a high security
collection room in the Museum and there is some type of
security device with motion scanners and whatnot very near the
computer. ( I learned this after the trouble started
happening.)  When the doors are either unlocked in the AM or
locked in the PM, the security company sends some signals into
the security system for verification.  The clustering of these
bad writes leads me to suspect some high frequency
interference triggering an error message or, in fact, a bad
write to disk.

This is only the current theory and I will suspect everything
until I find the problem, but the plot of the times sure isn't
anywhere near random.

There are no cron processes scheduled during these times so
nothing should be writing to disk anyway. 

Any more help/ideas are welcome.

Mark T. Dornfeld
Royal Ontario Museum
100 Queens Park
Toronto, Ontario, CANADA
M5S 2C6

mark at utgpu!rom      - or -     romwa at utgpu