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From: Joe Greco <jgreco@brasil.moneng.mei.com>
Message-Id: <199610291728.LAA24544@brasil.moneng.mei.com>
Subject: Re: Request to add this to FAQ re: swap space
To: bsdcur@shadows.aeon.net (mika ruohotie)
Date: Tue, 29 Oct 1996 11:28:03 -0600 (CST)
Cc: dyson@FreeBSD.org, dtc@scrooge.ee.swin.oz.au, current@FreeBSD.org
In-Reply-To: <199610291340.PAA24942@shadows.aeon.net> from "mika ruohotie" at Oct 29, 96 03:40:25 pm
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> somehow, i've learned the formula for swap space to be 3.5 * ram

The real formula for swap space is "more than you can possibly imagine
needing"...

Solaria, my venerable old Sun 3/60 (maxxed out at 24MB RAM):

(solaria.root.q4-2) 11:24am ~ 80 # pstat -s
16984k allocated + 1592k reserved = 18576k used, 177656k available
(solaria.root.q4-2) 11:24am ~ 81 # 

Showing that "8x RAM" is not unthinkable :-)

> wasnt that the "old" unix way? or something.
> 
> is there _any_ disadvantages from having a _lots_ of swap? since on "small"
> machines i tend to use, depending the amount of drives, swap from 24 to
> 72 megs... on each drives. on servers i tend to use 128 megs on each drive,
> and i always have atleast two drives... assuming i'd have 6 drives i would
> have some 700+ megs of swap, and probably "just" 128 megs ram, would i run
> into troubles? (with 2gig drive it's "easy" to give out 128 megs for swap)

Yes it is, and these days I would do it.

> what i mean, is there a number above which i'd get into troubles? (like say
> 1024 megs)
> 
> what kinds of swap spaces one needs on a news server? 

You do not really want to swap on a news server.  On my news servers I try
to go min 4x RAM but I have a fit if I see any substantial percentage being
used (I don't mind if daemons get swapped out).

> on a web server? i
> rather would not swap at all, but i'm not the one who pays the ram... =)

Boy do I ever hear that :-)

... JG