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From: std-unix@ut-sally.UUCP (Moderator, John Quarterman)
Newsgroups: mod.std.unix
Subject: Re: The POSIX file system
Message-ID: <6236@ut-sally.UUCP>
Date: Wed, 5-Nov-86 10:05:40 EST
Article-I.D.: ut-sally.6236
Posted: Wed Nov  5 10:05:40 1986
Date-Received: Wed, 5-Nov-86 22:18:40 EST
References: <6193@ut-sally.UUCP>
Organization: IEEE P1003 Portable Operating System for Computer Environments Committee
Lines: 42
Approved: jsq@sally.utexas.edu
Summary: No matter where the layer, the layers idea is good.

From: seismo!hadron!jsdy@sally.utexas.edu (Joseph S. D. Yao)
Date: Tue, 4 Nov 86 23:03:27 est
Organization: Hadron, Inc., Fairfax, VA

In article <6193@ut-sally.UUCP>:
>From: rgenter@labs-b.bbn.com (Rick Genter)
>Date: 30 Oct 86 09:57:13 EST (Thu)
>
>... various flavors of Unix (such as MERT, Unix' real-time cousin), 
>implemented the file system completely outside the kernel, I suppose as a
>library of routines.  ...
>     If any sort of fundamental change is to be made to the file system for
>POSIX, I'd prefer moving towards a non-kernel file system.  In addition to
>simplifying the design of the operating system, it also allows users to
>implement layers on top of the file system, such as case insensitivity,
>wildcard expansion, network file systems, access methods, etc.  Gee, is this
>starting to sound like streams?

The details of implementation, such as in or out of the kernel,
and streams, are really irrelevant.  Having the file system as
a separate, layerable part of the system interface as a whole
is a wonderful idea.  This conforms with ideas of modularity,
motherhood, apple pie, and so forth.  Both 4bsd and s5 have, in
succeeding implementations, tried to isolate FS code at least
by file in the os:sys directories.

Recent versions of the Unix(R) operating systems even implement
file system switches, which are the next great step, and would
probably do everything that Rick or anyone else would like, even
to mounting MS-DOS, VMS, TOPS-20, or whatever file systems.  (Yes,
even 4.2+ FS's on traditional Unix FS's!)  But I haven't seen much
about them since they were first ballyhooed; and AT&T even seems
to be withdrawing theirs.  (They won't document it, saying that
they don't want anyone to use it because it might go away.)  Perhaps
this just means that they're thinking of adopting the Sun version
as a "standard"?  Does anyone know anything about this?
-- 

	Joe Yao		hadron!jsdy@seismo.{CSS.GOV,ARPA,UUCP}
			jsdy@hadron.COM (not yet domainised)

Volume-Number: Volume 8, Number 39