[TUHS] RFS was: Re: UNIX of choice these days?

George Ross gdmr at inf.ed.ac.uk
Sat Sep 30 01:22:04 AEST 2017


> I dunno why all the hating on diskless.  They actually work, I used the
> heck out of them.

The issue we (initially) had with Suns wasn't the stateful/stateless debate,
or indeed that they were discless.  It was that horrible "UNIX
authentication" that NFS used.

We had been using discless "workstations" and fileservers since around the
late '70s / early '80s, basically ever since we discovered that virtual
DECtapes were a whole lot faster than the real thing.  Our "filestores"
didn't trust their clients -- they did the authentication themselves -- so
we could let the students loose doing bare-metal practicals without having
to worry about them breaking in.  That model didn't work for us with NFS.

However, Sun were keen to sell us kit (and DEC didn't seem to be), and they 
could sell us things for less than we could build them ourselves, so we 
eventually ended up with a couple of hundred or so of the things.  And they 
swapped like mad and thrashed the network into the ground.

We split subnets, and split subnets (and had some interesting amd maps as a 
result of trying to keep traffic local) and eventually ended up with so 
many that we couldn't run them all through all the offices as the cable 
bundle was too big, which was a nightmare for the admin staff trying to 
allocate people to desks.  Twisted pair, and then switches, saved us from 
that problem!

(We also had an X-terminal lab for a while, with a couple of beefy Suns as 
CPU servers.  That had its own, different, contention issues.  We learned 
from that not to arrange things in neat blocks, as the students would come 
in after lectures and go for the first free machine nearest the door, so 
using the naive approach we could end up with one CPU server being totally
overloaded and the other practically idle.)

Now everything is a PC with a ginormous disc, and the contention has moved 
to CPU cores and GPUs.  The more you throw at it the more the academics 
will come up with some way to saturate the thing...

(<http://history.dcs.ed.ac.uk/archive/os/APM-filestore/FS.1976/> for my 
rewrite of the original Interdata filestore code, btw, and 
<http://history.dcs.ed.ac.uk/archive/docs/dcs-inf-network-history.pdf> for 
a bit more on our network history.  There was also a filestore version that
ran on VMS and served files from that out to the network, but I haven't
been able to get a copy of that back off tape yet.)
-- 
George D M Ross MSc PhD CEng MBCS CITP
University of Edinburgh, School of Informatics,
Appleton Tower, 11 Crichton Street, Edinburgh, Scotland, EH8 9LE
Mail: gdmr at inf.ed.ac.uk   Voice: 0131 650 5147 
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The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.




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