Subject: Re: MFS over ISO-9660 union mounted with no swap space?
To: Erik E. Fair <>
From: Mike Cheponis <mac@Wireless.Com>
List: tech-kern
Date: 05/19/1999 13:42:18
On Mon, 17 May 1999, Erik E. Fair wrote:
> I've been reading this, and I've come to the conclusion that the
> fundamental question has to do with deterministic system behavior.
> ...
> However, if you posit a single-user system (as in, just one user; not
> single user mode), then the OS shouldn't care so much about preventing the
> user from doing things we might otherwise consider unwise; it's his
> computer, let him thrash it as he sees fit (though a few "do you really
> want to do this?" warnings wouldn't be out of place).
> If we're going to support the widest uses of NetBSD, we need to develop
> more clear, distinct models of use and system settings for those models,
> e.g. single-user workstation, versus multi-user system, versus Internet
> server. Each has its own requirements and tradeoffs, and I think we can
> partition system behavior in such a way that both Mike and his opponents
> can be happy.

I do think this is bullseye right-on.  Single-person Workstation, Timesharing
System, Internet (HTTP/FTP) server, File Server, etc.: These have different
tuning knob settings for optimum performance.

(Incidentally, Mike's Law of Analog Hardware Design is: "The Goodness of a
Design is Inversely Proportional to the Number of Tweaks."  Similarly,
to the extent that the system can "out of the box" be used for a
wide variety of applications, this is better than having specific

> For my part, Mike, what you're suggesting gives me the same concern as most
> of the rest of the people arguing against you. However, I have no problem
> with supporting the behavior you want, provided that it defaults to "off".
> I would be happier if you could show that, as part of your implementation
> of that dynamism, you handled all the edge cases cleanly.

That's very fair and impartial.  This is one of the things that attracts me
to NetBSD: smart and experienced people trying to get the best possible
performance for a wide variety of platforms and usage models.  

When I can demonstrate some of the stuff I'm talking about, then we can
discuss which parts get distributed.


Incidentally, last night I was reading some of the "Open Source" book:

In <>
in the "authors" section, the blurb about McKusick mentions:

    "His particular areas of interest are the virtual-memory system and the
     filesystem. One day, he hopes to see them merged seamlessly."

Wow!  This is -exactly- what I was thinking about, with the addition that
the VM system could be seamlessly extended to the network.  I think I
need to talk with Kirk to see what he's been up to...