Re: [gentoo-user] <OT> How many GB for / partition?

[jarry@gmx.net]

Uwe Thiem <uwix@iway.na> wrote:

> There are too damn many myths about swap out there. Like this one:
> Always configure twice as much swap as you have ram. Why?

<OT>
Well, it depends on how swap is handled by system. In linux, your
total memory = physical memory + swap (as you wrote)

A couple years ago I got answer from HP, where they said with hp-ux:
total memory = physical memory + (swap - physical memory)
only if swap > physical memory !

and
total memory = physical memory
if swap < physical memory
(in other words, it was completely useless to have swap < phys.memory,
 and optimum was really swap = 2 * physical memory)

They explained to me, that hp-ux 11 (or at least that early version)
allocates part of swap of the same size as physical memory and mirrors
the whole image of ram into swap for performance reasons: when more
memory is needed, it can be immediatelly made free, because it is
already paged to disk. 

So when I had 1GB RAM and 2GB swap, even right after system boot-up
only 1GB of swap were free (in the other half of swap there was already
mirror of physical memory), and I could not start any process which
needed more than 2GB total memory.

It seemed to me to be a complete vaste, and I was really angry, because
it was time when 4 GB disk was a luxury (and e.g. irix did not have
this strange "feature"). But things might have changed since then...
</OT>

Jarry

-- 
Telefonieren Sie schon oder sparen Sie noch?
NEU: GMX Phone_Flat http://www.gmx.net/de/go/telefonie
-- 
gentoo-user@gentoo.org mailing list