Are fileservers a waste of money?

[Paul Elliott]

We currently have network running SunOS 4.0 consisting of:

fileserver	Sun3/260	16M memory	xylogics 451
						1 x fujitsu eagle
						1 x fujitsu swallow
With the following diskless clients.

1 x client	Sun3/60		12M memory	(lisp programming)

3 x clients	Sun3/50		4M memory	(lisp programming)

2 x clients	Sun3/50		4M memory	(C & fortran)

The performance of the above network can deteriorate markedly as swapping
activity increases. This is especially so as more lisp processes are
running. Even the 3/60 with 12 Meg suffers poor response times when there
are two or more lisp processes running.

The problem is getting access to swap space on the disk.

We will be adding some extra clients over the next few months and wish to
upgrade the existing hardware and/or buy a more powerful server.

What we would like to know is where to spend the money.

The alternatives appear to be :

1. New high speed disk for existing server.

2. New more powerful fileserver with high speed disk.

3. Providing 3/60s or equivalent with 20 Megs for the lisp programmers
   and upgrading the 3/50s.

4. Providing local SCSI disks giving each client local swap space
   (dataless client configuration)

5. Some combination of the above.

We would especially like to hear from sites that have a similar
configuration to ours and also run memory intensive applications.

Looking at the alternatives above we could spend money on a more powerful
fileserver or a similar amount on additional memory and local disks for
each client. For money spent which alternative gives the best performance
improvement.

I personally feel that a more powerful fileserver is still going to suffer
a bottleneck at the disk with clients fighting for access to swap space,
even if a new server provided twice the disk I/O speed compared to the
existing server.