From: evansmp@uhura.aston.ac.uk (Mark Evans)
Subject: Re: Distributed computing under Linux?
Organization: Aston University
Date: Fri, 13 Nov 1992 09:23:51 GMT

Bill.Saunders@launchpad.unc.edu (Bill Saunders) writes:
: Hello all,
: 	I'm wondering if anyone has thought of trying to get a
: multiprocessing system working under Linux?  Last night I was
: trying to compile something while talking on the modem.  I only 
: have a 386-40mhz machine and the constant disk access was making
What speed modem were you using?
: things go slowly.  I thought about speeding things up by setting
: up a network in my home with just a 386 motherboard and a hard
: drive and ethernet card.  Then using X and Linux I would be able
: to transfer the source over to the second machine and compile it
: there without a speed loss.  

If you want to be able to access files on another machine NFS might be better.

: 	Then I thought about going to the minimal.  What if all
: I had was the 386 and memory and ethernet card?  It wouldn't speed
: up disk access(in fact it would slow it down-across the ethernet),
: but I could run another program over there and basically not 

Untill mmap(2) is finished you cannot do this, as you need to have
executables on a local disk (minix/extfs) to be able to run them currently
under linux.

: slow down my machine.  Could this be done?  Does X running on the
: remote machine need a video card?  A pretty inexpensive system 

The X server needs to be running on a machine with a display, the X clients
can be running on anything which can connect to the server.

: with just a 386mb,4meg RAM, and a ethernet card coud be made. Probably
: less than $400 bucks.  Would this be practical?  Is it cheaper to 
: get a 486-33mhz or two or three 386-40's?

Stick a 20M hd on these then you can run some X clients on them, if that
is what you are thinking.

: 	Then my brain had a massive surge of thought, what if
: someone rewrote the kernel and made it distributed?  Networks
: are getting faster and faster.  FDDI(fiber optics) can push 100Mb
: compared to 10Mb(not sure of units but sure of values) on 
: ethernet.  This would be a complicated job but it has been done.
: 	It would be easier to write a set of routines to do remote
: procedure calls.  The benefit of rewriting the kernel would be
: that less memory would be required on the remote(slave) computers.

They have already been written, check out the sunrpc.

: If we use X or remote procedure calls then the whole Linux kernel
: needs to be running on the remote machine.

That is because neither really support the concept of a slave system
only of clients (slave processes)

Both X and RPC support loosely coupled distributed systems.
I don't see where you get the idea of less memory.

: 	AnywayS, the main question is - is it possible to hook up
: a 386 Mb, 4Meg RAM, a remote booting ethernet card and run Linux 
: and X on it?????

If your question is can you run a 'diskless workstation' using linux
the answer is not yet (there are still problems to be sorted out
with executables)

What you could do is take mother board and HD, take the display and 
keyboard bits out of linux (use com 1 as the console).
You then simply have a 386 (or 486) unix box (most of your cost savings
are in not having a monitor or a display) you can then do just about
anything you like, except run an X server on this machine.

For an X client you need something running a transport protocal (e.g. 
TCP/IP) which the X server understands and a network connection to
the machine running the X server.
-- 
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Mark Evans                                   |evansmp@uhura.aston.ac.uk
+(44) 21 565 1979 (Home)                     |evansmp@cs.aston.ac.uk
+(44) 21 359 6531 x4039 (Office)             |