Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!rose!nowicki
From: nowicki%rose@Sun.COM (Bill Nowicki)
Newsgroups: comp.dcom.lans
Subject: Re: NFS vs RFS (actually, vs Sprite and Andrew)
Message-ID: <45660@sun.uucp>
Date: 16 Mar 88 01:05:29 GMT
References: <10370@ut-sally.UUCP> <720@uel.uel.co.uk> <1695@uoregon.UUCP>
Sender: news@sun.uucp
Lines: 43
Keywords: NFS, ANDREW, TOCS, consistency
Summary: NFS and beyond....

In article <1695@uoregon.UUCP>, jqj@uoregon.UUCP (JQ Johnson) writes:
> The latest issue of TOCS (Feb. 1988) contains 2 papers from the 1987
> SIGOPS Symposium that are directly relevant to a comparison of network
> file systems.  A paper by John Howard et al discusses the VICE system
> (part of the C-MU Andrew project), and a paper by Nelson et al discusses
> Sprite, a network file system being developed at Berkeley.  
> 
> Problems sited with NFS seem to fall into 2 categories:
> 1/	scalability to large systems, because of excessive network
> 	traffic, excessive server cpu loading, or difficulty in 
> 	administration;

Well of course the authors of systems are going to prefer their own.
This is called the "Not Invented Here" syndrome.  As for scalability,
I would estimate about 100,000 installed systems running NFS.
Last I heard, about 500 run Andrew, and perhaps a few dozen run Sprite.

Don't get me wrong: these were good papers and have significant
research contributions.  NFS is a commercial product developed four
years ago, so of course the research has to be done first. Note that
Sprite explicitly gives up heterogeneity and crash recovery, and VICE
assumes a local disk.  Both of these projects were done on
Sun workstations, so we are happy to see good results.

> 2/	problems with consistency semantics.  For example, under
> 	SUN NFS if processes on different workstations perform
> 	interleaved write to a file the result is indeterminate.

Sure -- if two timesharing users perform interleaved writes on the same
file the result is also indeterminate.  "transparency" :-)

We are working on further revisions of the NFS specification.
Copies were distributed at the recent "Connectathon" for all
NFS licensees (and anyone else who wanted to show up).

The problem (feature?) is that we are a small group, so do not
necessarily rush out and implement the fad of the week. On the
other hand (please pardon the plug) we are hiring. Send resumes.

	-- Bill Nowicki
	   Sun Microsytems

(not an official spokespeon!)