Subject: Re: Swap sizes vs. physical memory.
To: Manuel Bouyer <bouyer@antioche.lip6.fr>
From: Richard Rauch <rkr@rkr.kcnet.com>
List: netbsd-help
Date: 09/09/1999 01:04:50
First, thanks to all who gave me feedback.  As the preponderance of
replies said, there appears to be no problem with having more RAM than
swap.  I'm not sure where I got the notion that there might be a
problem---but I'm glad that my concerns were misplaced.


> > 2) Is there a lower limit on swap space for normal systems? The boot
> >    floppy may have an unusual system.
> 
> No, you can run without swap space at all if you want. It's just that sometimes
> it convenient to have a core dump from a crash.

I was more or less aware that you could shut it off completely, but until
this thread came up I didn't think about the core issue.  I don't think
that this is addressed in the docs.  And, in the same breath, it may be
worth explicitly stating in the docs that the amount of swap-space that
you have can be adjusted totally independant of the amount of memory.

Offhand, the only system docs that I know to look at are the swaptctl(8)
man pages.  On v1.4, there is the following warning, which tends to imply
that swap-space is ``eventually'' necessary for everyone:

> > 3) Is there a document out there with more intelligent quidelines than
> >    'four times physical memory'?
> 
> don't know :)

The ``four times physical memory'' figure comes from the default
configuration.  I'm not sure that there are any docs that suggest that
figure.

Some kind of advice about this during (or before) installation might be
nice.


  "I probably don't know what I'm talking about."  --rkr@rkr.kcnet.com