Hello,

I saw this line when I booted up one of our servers:
WARNING: Red Hat Enterprise Linux ES release 4 (Nahant Update 6) requires no more than 16384MB RAM to run as a supported configuration. (32137MB detected)

The kernel version of the server is: 2.6.9-55.ELsmp

What does it mean exactly?
Do we need to update to the hugemem kernel?
Do we need to update to RHEL AS?

Thank you
Jocke

As far as I understand message and its source (and the fact that it is a warning) it means the following:
1) run "free" command, it will report that all your 32GB RAM is accessible;
2) it is not about technical limitations at all, so package updates are not needed/will not fix it
3) your support contract states the range of configurations where you can run RHEL and get the support. So if you try to get support for some non-trivial problem from RedHat, you will have to bring the box down, take half of RAM from it, reproduce problem in this configuration and only then seek support. Another option is paying some more for support contract upgrade (sorry, I cannot say anything more specific)

I think this message mean that RHEL-ES not supporting more than 16GB and 2cpu, so if you will use HW more than 16GB or 2cpus you shall buy RHEL-AS.
talk a look there https://www.redhat.com/rhel/compare/