Microsoft Windows Server 2003 only supports NUMA configurations with PAE enabled - IBM eServer xSeries

Resolving The Problem

RETAIN Tip: H177860

Microsoft Windows Non-Uniform Memory Access (NUMA) application programming interface (API) calls return a single node configuration, irrespective of the number of hardware nodes present, if Physical Address Extensions (PAE) support is not enabled.
 
Note: This behavior occurs on systems configured with NUMA and with with PAE disabled.
 
For example, a 4 node NUMA system configuration with 4GB or more of memory installed, and not running the PAE kernel. (because it is under the "above 4GB" requirement)
 

The system may be any of the following IBM eServer xSeries servers:

• x450, type 8688, any model
• x440, type 8687, any model
• x445, type 8870, any model

The following network operating systems are affected:

• Microsoft Windows .NET 2003, Standard Edition
• Microsoft Windows .NET 2003, Enterprise Edition
• Microsoft Windows .NET 2003, Web Edition
  

Enable the PAE Kernel.

Enabling the PAE kernel

1. Edit the boot.ini file in your system's Windows root installation directory
2. Add the switch /PAE to the line of text under the operating system reference.
   
   For example, before editing:
    
   multi(0)disk(0)rdisk(0)partition(1)\WINNT="Microsoft
   Windows 2003 XXX" /fastdetect
    
   and after editing:
    
   multi(0)disk(0)rdisk(0)partition(1)\WINNT="Microsoft
   Windows 2003 XXX" /fastdetect /PAE
   
   
3. Save your changes and exit.