I don't have good info handy, but a while we saw problems when running
Oracle 8.1.7.x on a >4 GB RAM Linux box in the past (which some late
version of the 2.4.x kernel). I think it had to do with running out
of "low memory".
It was pointed out to me that Red Hat's
Linux 2.6 vs. RHEL 3
kernel feature summary has some relevent info.
This RHEL feature, which apparently is not in the 2.6 kernel,
might be the correct fix for the "low memory" problem:
- 4GB-4GB memory split: Greatly increased x86 physical memory
support and larger application address space
And these, all of which are in both the RHEL 3 and Linux 2.6 kernels,
might be related:
- Reverse Map Virtual Memory (rmap VM): Performance improvement in memory constrained systems
- HugeTLBFS: Performance improvement for large virtual memory applications (e.g. Databases)
- Remap_file_pages: Kernel memory optimization for shared memory applications
