On Sat, 3 May 2008, Woodchuck wrote:

> On Sat, 3 May 2008, Morton D. Trace wrote:
> 
> > For the  4.2 version of open BSD, how large should the swap partition
> > ideally be?
> > 
> > is the size the same for i386 and amd64 ?
> > it depends only on physical RAM, please?
> 
> It depends on your needs...  You don't need swap, and won't
> use swap, until your machine is running enough processes that
> it runs out of physical ram.  This can be due to a single
> pig of a process (notoriously, mozilla/firefox), or to many
> smaller processes.  Some servers need lots and lots of memory
> (swap is part of that), some need no swap at all.

a little addendum:

I'm looking now at a site at freeshell.org, running NetBSD on an
"AlphaServer DS10L 466 MHz", where the top command gives: (format
slightly different from OpenBSD)

load averages:  2.39,  1.97,  1.40                                     00:05:23
211 processes: 1 runnable, 208 sleeping, 1 stopped, 1 on processor
CPU states: 67.5% user,  0.0% nice, 32.2% system,  0.2% interrupt,  0.0% idle
Memory: 472M Act, 254M Inact, 2152K Wired, 34M Exec, 434M File, 84M Free
Swap: 1024M Total, 242M Used, 782M Free

This machine appears to have 1 GB of RAM and 1GB swap.  Currently, 52
interactive shell users are active.  Mostly these people are
running email, IRC or text-based web-browsers, nearly all are connected
by ssh, so I imagine a major part of CPU load is with crypto. The
site also has fourteen instances of the httpd daemon active (probably
clones), a mysql server, sendmail and a couple other of the usual
services.  This is a typical load for this host.

vmstat and "systat vmstat" is another good monitor of swapping.

Observe the PAGING  and SWAPPING  part of the display, (top center
on OpenBSD).

Swap statistics from top seem to be a high water mark, not an
indicator of current swapping activity.

On older systems you can tell when it's swapping from the sound
of the disk drive.  But drives are getting quieter these days.
A machine actively swapping on a 14" (35cm) disk sounded like
a washing machine on "spin".

Dave
_______________________________________________
Openbsd-newbies mailing list
[email protected]
http://mailman.theapt.org/listinfo/openbsd-newbies

Reply via email to