adding swap partition

[Rick Stevens]

Ajai Khattri wrote:
> On Fri, 11 Jun 2004, Rick Stevens wrote:
> 
> 
>>Yes, but that's just a rule of thumb.  It can vary widely, depending
>>on what you ask the machine to do.  If you run a lot of big programs
>>simultaneously, you'll want more swap.
> 
> 
> True, it depends on the server usage. If you're planning memory upgrades
> you may want to make it less (or more if you're running a big database
> and dont have enough RAM). I suppose stuff like this falls under "fine
> tuning" of a system and is a subject unto itself.

Precisely.  One of the nice things about swap _files_ is the ability to
create them "on the fly" if you need them.  If you're stuck with swap
_partitions_, you have to futz with your disk layouts.  Ugh!

> [In certain situations it may even make sense to have no swap at all - I
> have NetBSD running off a 256Mb CF Card on an NEC MobilePro 780 (WinCE)
> machine where you probably *dont* want constant swap writes wearing out
> the flash card! (Mind you I configured that machine to run almost
> nothing - at boot it has maybe 5 processes running and nothing else, not
> even any virtual consoles. I have a wireless card in it and use it as a
> very portable wireless ssh terminal ;-) ]

Yes, that's true, but PDAs and the like are "special cases".  For most
users and servers (note I said "most"), a single swap partition or file
that's 2x your RAM is enough.  If you need more, use the stuff I posted
before to create a swap file and activate it.  Simple.
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- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
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