[P1] To Partition or...! Virtual Memory

[Joost van de Griek]

On 2003-06-01 19:26, Tom R. no spam wrote:

> Well, looking more closely I saw the 34 pageouts.  (I don't
> know why the "(0)" after the "34", and that's what my eye
> glanced at before.)

The 34 is the total number of pageouts since the system was started. The (0)
is the number since the top listing was last refreshed. Basically, it says
that VM has been hit since you last rebooted, but that you are not using it
right now.

>  As I said before, I don't know why
> there would be any pageouts in my system as setup and running
> at this time, unless OSX has some memory use scheme different
> from what I know about unix.

OS X is very different from UNIX in this regard. It doesn't use a scratch
partition, for starters, but scratch files, and can easily use more than one
of them. Therefore, the usual "scratch partition == 2 * physical RAM"
rule-of-thumb doesn't hold up on OS X, either.

You can be running relatively few apps, and suddenly experience peageouts
when one of them decides it needs a ton of RAM all of a sudden.

But when your top reading stays at (0) for a while, things have calmed down
and VM isn't doing much, if anything. Besides that, 34 is a very low
reading, so nothing to get hung up over. I usually hit something like 40,000
by lunchtime, doing Java/JSP development on my iBook. Yes, that's with 640
MB RAM.

,xtG
.tsooJ
-- 
Real programmers always mix up Halloween
and Christmas, because Oct 31 == Dec 25
-- 
Joost van de Griek
<http://www.jvdg.net/>