There are two types of PDomain configurations available for the compute servers:
Base configuration PDomain – Two or four PDomains, on either one or two severs, where one DCU is associated with each PDomain. Base configuration PDomains allow for greater flexibility around availability.
Extended configuration PDomain – Two PDomains, on either one or two servers, where two DCUs are associated with each PDomain. Extended configuration PDomains allow for more resources (CPU, memory, IB HCAs, 10GbE ports and internal hard drives) to be concentrated in one of the LDoms in that configuration.
Both configuration types support from 1 to 4 LDoms each. See Understanding PDomains for more information.
The following table provides information on the amount of resources that's available at the overall PDomain level for the different configurations. Keep the following information in mind when reviewing the information in the following table:
A fully-populated DCU contains four CMUs, and a half-populated DCU contains two CMUs
Each CMU contains two processors
Each CMU contains 64 DIMM slots
How these resources are divided between LDoms within these PDomains depends on the type of LDom configuration you choose. See Understanding LDoms for more information.
When determining which PDomain configuration that you want for your system, consider if you need a configuration where one of the LDoms would have one or more of the following characteristics:
More than eight processors
More than 4 TB of memory (16 GB DIMMs) or 8 TB of memory (32 GB DIMMs)
More than four IB HCAs
If you want an LDom with any of the characteristics listed above, then you should choose one of the extended configuration PDomains. If none of the LDoms in your system needs to have any of the characteristics listed above, then you should choose one of the base configuration PDomains.