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From: albert@krakatoa.ccs.neu.edu (Albert Cahalan)
Newsgroups: comp.unix.bsd.freebsd.misc,comp.os.linux.development.system
Subject: Re: The better (more suitable)Unix?? FreeBSD or Linux
Date: 23 Feb 1996 03:01:17 GMT
Organization: Northeastern University, College of Computer Science
Lines: 35
Message-ID: <ALBERT.96Feb22220117@krakatoa.ccs.neu.edu>
References: <4er9hp$5ng@orb.direct.ca> <4f9skh$2og@dyson.iquest.net>
	<4fg8fe$j9i@pell.pell.chi.il.us> <311C5EB4.2F1CF0FB@freebsd.org>
	<4fjodg$o8k@venger.snds.com> <4fo1tu$n31@news.jf.intel.com>
	<DMrCE4.3HF@pe1chl.ampr.org> <4ftjt9$fjs@park.uvsc.edu>
	<DMv8w7.8H4@pe1chl.ampr.org> <4g5ivp$28m@park.uvsc.edu>
	<4gejrb$ogj@floyd.sw.oz.au> <Dn67EK.3nB@pe1chl.ampr.org>
	<4gilab$97u@park.uvsc.edu>
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In-reply-to: Terry Lambert's message of 22 Feb 1996 20:56:43 GMT
Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:14222 comp.os.linux.development.system:17844

>>>>> "T" == Terry Lambert <terry@lambert.org> writes:

T> rob@pe1chl.ampr.org (Rob Janssen) wrote: ] Don't bother to tell Terry about
T> your experiences, he will just declare ] your system obsolete and your
T> tools out-of-date.  ] Remember: sync metadata updates only work well on
T> *his* system.  ] On all others, it is just a drag.

T> Imagine that... I must have a lot of gall to declare obsolete a file system
T> implementation that doesn't properly conform to the design documents from
T> which it purports to be dervied.

T> Silly me.

T> Apparently, not having read the documents, you don't realize that it is
T> *impossible* for a conforming implementation to result in the errors you
T> want to attribute to UFS -- short of a unrecoverable hardware failure.  Do
T> you not believe that finite state automatons are deterministic?  I can
T> assure you that they are.

Proofs are great for filesystem development.
They are useless for testing; you should know this.

You can "prove" that something works, but how can you be sure
that the code matches your proof?  Yeah, you read it.  So what.
People make bad proofreaders because they see what they expect to
see.  You can prove that a fictional filesystem works, but you
can only test, test, and retest a real filesystem.  We're not
talking about hello_world.c here.  Even if the code really is
good (only God knows for sure), you can hit compiler bugs.
Maybe you will make a mistake in your reasoning.  You can _never_
prove that your filesystem is correct, but you can test it.
--

Albert Cahalan
albert@ccs.neu.edu