64GB RAM Problem

[Mark Clarkson]

Hi,
I'm having problems with a Dell R900 with 64 GB RAM.
I can't create a 40GB file without Out Of Memory errors,
usually followed by a system hang (due to killing init).

This only happens with 32bit RHEL, which is what I need,
64bit is okay. The file stops growing at 22GB when the
cache memory reaches 22.5GB. This problem doesnt happen
with 32GB RAM.

Has anyone been able to create a big file on 32bit RHEL
on different hardware with 64GB RAM?

I used:
  dd if=/dev/zero of=bigfile.delme bs=1k count=$((24*1024*1024))

Cheers
Mark.