[comp.dcom.lans] Question about running multiple Mac's off 1 Mac 'server' using TOPS

jeff@drexel.UUCP (Jeff White) (08/23/88)

   In our department office, we have 5 Mac Pluses: 3 have external drives
and ImageWriters connected to them, another has an HD20 (probably SC) and
an external drive, and the last an Hyperdrive FX20 and ext. drive.  With the
growth of the Macintosh System ('System', 'Finder', as well as other 
applications, ie. MacWrite 5.0 w/ dictionary is about twice the size as 4.6),
it's getting very difficult to have even a standard application disk with a
separate data disk.  Also, size limitations prevents access to all the fonts,
and the correct ones as well (I forgot to mention that all the machines are
connected to Apple (oops, LocalTalk), right now basically to share a 
LaserWriter+ printer.
  I mentioned to our dept. head that using TOPS, one machine (or really, as
many as you want) could be set up as a nondedicated server, so that everyone
wouldn't need their own copies of applications (their data files would
most likely be kept on floppies, though).  In addition, I mentioned that using
TOPS, it was possible to double click on the Finder on that server, and 
effectively have it become the startup disk (the benefit being that you could
load up one System with all the fonts, DA's that you needed, and have 
everyone access it).
  Now, three questions.  Would this work as I would like it to, ie., can a 
single System and Finder support mutliple users?  It doesn't get written to, and
a partial copy (or at least data from it) is kept in RAM in everyone's machine,
so I wouldn't think there should be a problem?  Second, would printing still
work properly?  If you had three people, each running the same System and 
Finder, the same application (ie. MacWrite), and accessing the same LW and 
LWPrep files, would things still be okay?  Last, how would applications that
write or modify data files work?  A specific example would be MacWrite 5.0 with
it's spelling dictionary.
  I should probably mention a few other things.  First, we have an old Lisa
around, with a 10 Mbyte interal and 5 Mbyte external drive that could be
upgraded to function as a dedicated server if neeeded.  I'd rather not go the
dedicated server route unless necessary.  Second, the server would be an
application and System server, not really a (data) file server, so something
like AppleShare (with separate logins, user directories and heavy permissions)
would probably not be necessary.  Lastly, we have a Sun 4 which I can point
out at least has the potential to be Tops server (after getting the Tops Unix
software and a Kinetics gateway box), maybe an additional selling point of Tops.
  I would very much appreciate any information you could provide.

									
						Jeff White
						Drexel University - ECE Dept.
						rutgers!bpa!drexel!jeff

Ps.   One additional question about TOPS I'd like to ask.  I know that TOPS
    is serialized, so that you have to buy a separate copy for each user.
    Is there any way that it can be configured so that each TOPS user disk
    has copies of the other serial numbers?  Here's an example.
      Suppose you 5 Mac's (1-5) on LocalTalk, but you only buy three copies of
    TOPS (A-C), ie. you only want 3 people to be able to use it at once.
    Ordinarilly, user 1 would get disk A, 2 gets B, and 3 gets C.  Users 4 and 
    5, who would use it less frequently, would get copies of A and B (4 gets A
    and 5 gets B).  Now, if users 1 (A), 2 (B), and 3 (C) were on, users 4 and
    5 wouldn't gain access (the message, 'Already in use', or something like
    that, would probably come up).  But suppose only user 1 (A) was on.  User
    4 (who has a copy of serial disk A) still wouldn't be able to get on, even
    though (in a roundabout way) you paid for 3 users.  It would be nice if
    4's boot disk had copies of the other serial codes, so that when it tried
    to load TOPS using serial code A (and found it was already in use), it would
    then try B and C, basically hunting through all of the available codes.
       I can't see giving users 4 and 5 three separate disks (ie. they boot up
    with serial code A, see if it's available, if not, reboot with B, and so
    on).  This is probably what I think would have to be done, but I would
    like to knew whether my way is possible.

phil@mit-amt (Phil Sohn) (08/24/88)

	The answer to all your questions is no, I'm afraid.

	No, you can not have different people running the same system
and finder.  You would have to have a seperate folder for each. 
(i.e. for five users you would need five system folders on the "server."
You would also have to have five copies of most programs as very few
are multi-launch.

	No,{you can not get by easily with only bying three disks.  The
only way I can think of would be to try booting from different floppies.
There maybe a way around this thought.  I think the serial number is in
an INIT and perhaps you could have multiple copies of the init in the
system folder.  (I am not sure of this.  I am also not sure what would
happen if you had three copies in you system folder and no one else was
using the system.  Perhaps all three copies would become busy?)

	Another problem would be that that one person how has a 
"non-dedicated server" would have serious performance problems if
several people were using his hard disk.

	It has been almost a year since I played with Tops, so it is
possible that my info may be way out of date.  Give them a call.