Path: utzoo!utgpu!news-server.csri.toronto.edu!clyde.concordia.ca!mcgill-vision!quiche!utility
From: utility@quiche.cs.mcgill.ca (Ronald BODKIN)
Newsgroups: comp.os.misc
Subject: Re: (Free) book on the Amoeba distributed system available
Message-ID: <2629@quiche.cs.mcgill.ca>
Date: 26 Mar 90 07:56:20 GMT
References: <6067@star.cs.vu.nl> <2604@quiche.cs.mcgill.ca> <6106@star.cs.vu.nl>
Reply-To: utility@quiche.cs.mcgill.ca (Ronald BODKIN)
Organization: SOCS, McGill University, Montreal, Canada
Lines: 30

In article <6106@star.cs.vu.nl> ast@cs.vu.nl (Andy Tanenbaum) writes:
>I thought QNX was basically a UNIX-clone.  You log into one specific machine
>and work there, with access to others via rlogin and explicit file motion.
>Correct me if I am wrong.  
	You are wrong.  You can access another machine this simply:
[2] ls
	This would perform (on machine 2) an ls command.  If your current
directory is on a remote machine, it is totally invisible to you that you
are not using a local directory.  For example, if your user directory is
on machine 1 and you login through machine 2, ls will list the directory
on machine 1 automatically.

>In Amoeba you just log in.  When you say the equivalent of ls -l, you see
>a bunch of files.  Some might be in your machine room, and the rest might
>be spread over a dozen sites in as many countries.  You can't even tell
>where they are unless you look hard.  When you start make, it runs all
>the compilations on as many processors as it can find, in parallel.  This
>is what I mean by a distributed system--there is no concept of a home machine
>where work is done by default.  There is just a big pool of resources which
>the system allocates automatically.  Is QNX like that?
	QNX is essentially like this.  The file structure is invisible, one
does have an open pool of resources (tasks spawn and communicate across the
network as easily as they would on one machine -- the same set of tasks that
work on a single machine will distribute across a network with no
modification) but there is a very tiny amount of defaulting of work due to
the way of some applications are written.  There is no reason to have it be
so, for example QNX does support a parallel make facility, and any
application can be written so that it distributes automatically, if this is
desired.
		Ron