You can configure the server with PDomains or Bounded PDomains.
A Bounded PDomain can have from zero to four CMUs, using any combination of CMU slots in a DCU.
By default, factory configurations use PDomains, where DCUs are either fully-populated (four CMUs), half-populated (two CMUs), or empty (zero CMUs). For half-populated DCUs, the factory installs CMUs in the first and fourth CMU slots in a DCU (for example, CMU0 and CMU3 in DCU0).
For more information about PDomains and Bounded PDomains, refer to Server Administration, DCU, CMU, and CMP Guidelines.
Other half-populated configurations are supported on PDomains but have these limitations.
In a PDomain, if a CMU fails in a half-populated DCU, the DCU can lose access to PCIe slots, EMS slots, and SSBs. Refer to Server Administration, PCIe and EMS slot information.
Caution - To prevent overheating, fill unused CMU slots with CMU filler boards. This rule does not apply to a DCU that has been temporarily halted for service.