Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utcs!mnetor!seismo!husc6!harvard!cmcl2!acf4!tihor
From: tihor@acf4.UUCP
Newsgroups: net.unix
Subject: Re: Favorite operating systems query (UNIX vs VMS flaming!!!)
Message-ID: <9250002@acf4.UUCP>
Date: Sat, 12-Jul-86 16:29:00 EDT
Article-I.D.: acf4.9250002
Posted: Sat Jul 12 16:29:00 1986
Date-Received: Sat, 12-Jul-86 23:21:55 EDT
References: <1000@ttrdc.UUCP>
Organization: New York University
Lines: 22

>/* acf4:net.unix / davidsen@steinmetz.UUCP /  1:46 pm  Jul  8, 1986 */

I believe that Mr. Steinmetz has misunderstood the term "Transparent
file sharing" in his comment:

> File sharing under VMS is about as non-transparent as you can get! 
>If I want a file on another machine, I type
	othermach::device:[many.sub.directories]file.typ

The term has most often been used to mean Transparent to the application
using the file, not "syntacticly invisible to the use" (although that
property has considerable appeal in many cases.)  In this sense 
DECnet file access as implemented in VMS and some other DECnet libraries
is indeeed highly transparent.  Very few operations on XYZ::FRED.LIS are
forbidden that wouldbe permitted on FRED.LIS.

W/R/T VAXcluster they should be viewed as loosely coupled multiprocessors
which currently share (principly) their file systems.  In the long run they
seem to be evolving into full if loosely coupled multiprocessors.  The
fact that they share separate but cooperating system images that can fail 
separately is an important characteristic and very different from some 
tightly coupled multiprocessors which will only fail together.