Path: utzoo!mnetor!uunet!husc6!mailrus!ames!oliveb!sun!sluggo!melohn
From: melohn%sluggo@Sun.COM (Bill Melohn)
Newsgroups: comp.dcom.lans
Subject: Re: NFS vs RFS (actually, vs Sprite and Andrew)
Message-ID: <46253@sun.uucp>
Date: 21 Mar 88 06:05:26 GMT
References: <10370@ut-sally.UUCP> <720@uel.uel.co.uk> <1695@uoregon.UUCP> <45660@sun.uucp> <8428@tut.cis.ohio-stRe: NFS vs RFS (actually, vs Sprite and Andrew) <3af44ad7.b8ab@apollo.uucp>
Sender: news@sun.uucp
Reply-To: melohn@sun.UUCP (Bill Melohn)
Organization: Sun Microsystems, Mountain View
Lines: 53
Keywords: NFS, ANDREW, TOCS, consistency

In article <3af44ad7.b8ab@apollo.uucp> rees@apollo.uucp (Jim Rees) writes:

>I've never used a large NFS system, but I'm currently using a system
>that includes about 2000 machines sharing a single file system.  Any
>file name can be used interchangeably by any machine.  I have a hard time
>imagining how this would work with NFS.

I'm not sure I understand why; there is nothing intrinstically more
complex about a NFS based distributed file system than one based on
propritary operating systems. On the contrary, scaling up tends to
show off many of NFS's design strongpoints; for example stateless
becomes much more important when you have a large number of file
servers which can be potentially down at any given point.

>For example, we have a few hundred people in R&D.  Almost all of them
>will at some time want to look at the kernel sources.  If you use NFS,
>how does this work?  Does everyone mount the file system containing the
>kernel sources all the time?  Do you just mount it when you want to
>look at the sources?  What happens when the sources move to a different
>machine?  Is it possible for 2000 clients to each mount a couple dozen
>servers?  How do you keep track of where the servers are?

Typically communities of interest will mount filesystems of interest
from a common set of servers. With NFS, these servers can be anything
from a lowly MicroVAX up to a Cray, and the client can be a
workstation, PC, or any one of some hundred odd vendor
implementations. Last time I checked, the Domain file system was only
available on a single family of processors from a single vendor. This
is fine if you happen to have a lot of these machines around (:-)),
but most big NFS users have a variety of machines from several
different vendors with which they would like to build a distributed
enviornment.

>If I write a trip report, and want to send it to a large group of people,
>I put it in a file and send the file name out via email (or news).  Then
>the people who want to look at it just read that file.  How would you do
>this with NFS?  E-mail the whole thing?  Send out the file name and let
>people mount your disk as needed?

Again, the difference between explicitly mounting a remote file system and
merely referring to it in a global name space seems fairly trivial. The
mount command under Unix is a super-user only command, but it would be
pretty easy to write a service that would mount a remote file system for
you (like the "on" command does) using NFS and the mount protocol.

>How does uucp work with NFS?  Does every machine mount the uucp lib and
>spool, or is there a single "uucp machine" that I rlogin in to when I
>want to uucp something?

At Sun, many users remotely mount the file system that contains newsgroups
from a central server, and then use the NNP to send posted articles to this
machine for centralized distribution. It is also possible to rlogin to
this machine directly.