[rhelv6-beta-list] 32-bit PAE Low Memory

[Bryan J. Smith]

Brian Long <brilong at cisco.com> wrote:
> Worst case, I could remove half the RAM and I'm sure
> LowTotal would increase.  I had 48GB RAM in this server and
> LowTotal was around 256MB.  :(

Yepper.  The i686 PAE kernel eats portions of the 1GiB of RAM until
it's exhausted as it closes in on 64GiB, for the paging.  At 48GiB,
you will be using 768MiB for paging.

This was the reason for the Red Hat 4G/4G model kernel in earlier releases,
which was a significant performance hit as the entire kernel-user paging
occurred in their own 4G areas.

It was not included in release 5.  I believe there are well-documented
recommendations on what is and is not supported, memory-size wise, for
release 5, because of the move to x86-64 by most enterprises to remove
these issues.

> Unfortunately I've been unable to get a certain 32-bit tool
> working on the x86_64 platform and for now I'm stuck running on a
> 32-bit PAE kernel.

This is really an ideal area where virtualization should be considered.


-- 
Bryan J  Smith             Professional, Technical Annoyance 
Linked Profile:           http://www.linkedin.com/in/bjsmith 
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