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

[Tom Sightler <ttsig tuxyturvy com>]

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 ?

Better is always a relative term.  I would say that RHEL4 is more
"tunable" and handling swap, but in most cases RHEL3 could be tuned to
handle most situations as well by increasing memory reclaim and lowering
the page cache.

RHEL4 has a "swappiness" setting that can be used to tune the overall
systems likelyness to swap when under memory pressure (as opposed to
reclaiming memory from pagecache).  I found this makes it easier to tune
for almost all of our cases than tuning RHEL3.  

Later,
Tom