Re: RHEL 4 improvement in use of swap? (compared to RHEL 3)

[Arjan van de Ven <arjan infradead org>]

On Thu, 2005-10-27 at 15:20 -0700, robert infotility com wrote:
> Hello,
> 
> First of all I've used Redhat distributions for several years and
> Linux has been almost entirely a pleasant and productive environment
> for me. Thanks to all responsible parties for the hard work which
> goes into every release.
> 
> My question is, is RHEL 4 known to be better at handling
> virtual memory (swapping in particular) than RHEL 3 ?
> 
> I have an ageing Dell box (2 x 450 MHz cpu, 256 M memory) running
> RHEL 3 update 6 (last updated circa 2005/10/01).
> Today it was running several Java programs, Mozilla, and various
> daemons, and perking along OK. The Java programs are terrible
> memory pigs but GUI apps response to mouse clicks and command line
> response to keyboard input was OK.


at some point... the VM subsystem only deals with VIRTUAL memory..
that's no substitue for real memory. If you really need more than 256 Mb
then it will suck always. Disk is just over 1000 times slower as ram,
and no amount of kernel hacking can fix that.

RHEL4 behaves different than RHEL3, better in a lot of cases. But
again.. once you're over the edge in requirements, there's not a whole
lot the kernel can do other than trying to keep the box alive.