Path: utzoo!attcan!uunet!munnari.oz.au!uhccux!ames!elroy.jpl.nasa.gov!david
From: david@elroy.jpl.nasa.gov (David Robinson)
Newsgroups: comp.protocols.nfs
Subject: NeFS overkill?
Message-ID: <1990Jun1.231507.13779@elroy.jpl.nasa.gov>
Date: 1 Jun 90 23:15:07 GMT
Sender: david@elroy.jpl.nasa.gov (David Robinson)
Organization: Image Analysis Systems Grp, JPL
Lines: 36

Having read the NeFS specification I consider it an interesting
approach to creating a networked filesystem between heterogenous
operating systems.  But I wonder how useful it will be in the real
world.

Looking at the current implementations of NFS clients the vast majority
use some sort of virtual filesystem or filesystem switch to provide a
mostly transparent access to remote files with minimal changes to
user level code.  For example: Sun VFS, AT&T FSS, PC-NFS redirectors,
VMS ACPs, and others. Few actually bury network specific code into
user level applications.  If you examine each of the methods currently
used, most gain very little from using an interpreter on the server.  The
example in the draft of implementing the Unix "du" facility is a nice
elegant example of NeFS.  Unfortunately without a completely new,
high level system interface, all the underlying OS 
and NeFS are going to see is a bunch of readdir and getattr
function calls. The interpretive nature of a server gains very little
functionality.

In addressing the hetrogenous nature, PostScript dictionaries are very
nice for providing the ability to have extensible and varying attributes
between systems.  But this can almost as easily be handled with
extensible data structures without the overhead of an interpreter.

With the exception of a minority of machines such as LISP machines
there is a great lack of technology to take advantage NeFS while
preserving the transparency of user level code.  NeFS is an interesting
technology but is it appropriate to solve the problems of the existing
NFS?

	-David
-- 
David Robinson	david@elroy.jpl.nasa.gov 	{decwrl,usc,ames}!elroy!david
Disclaimer: No one listens to me anyway!
"Once a new technology rolls over you, if you're not part of the steamroller,
 you're part of the road." - Stewart Brand