Disk errors

[Keith Price <PRICE%DWORKIN.usc.edu@OBERON.USC.EDU>]

I would like to know if anyone else has ever seen the following
type of error and, if so, what hardware was replaced to fix it.
(We have replaced everything except the disk.)  The error is 
"random," and the printed system error varies (illegal instruction 
51207 or 0, or an array access error).  The error only occurs when 
opening files with :direction nil (as occurs when reloading a system),
only for files on the local machine, and only on one of our machines.
One of the continuation options on the errors is to retry the open.
The retry always works and reading the file (:direction :input) always
works.  For example, the following simple program:

;;; -*- Mode: LISP; Syntax: Common-Lisp -*-

(defun test-error ()
  (dolist (f (cdr (fs:directory-list ">**>*.*")))
    (with-open-file 
      (str (car f) :direction nil :error nil :element-type :default))))

will sometimes give an error on a few files (in three tries: 2 files, 
4 files, and many files (approx. 50% of them)) out of several hundred.
I think it is hardware because it is occasional, inconsistent, and
may be temperature sensitive.  Going across the network also eliminates
the error (i.e. only a local machine opening local files will "fail").

	Keith Price
	price@dworkin.usc.edu
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