Cores Available for Domains and Zones

The number of cores available for LDoms, and for zones within those LDoms, varies depending on the following factors:

• The number of DCUs in each compute server

• The number of CMUs in each DCU

• The type of configuration PDomain that you have on each compute server

• The type of LDom configuration that you have on the PDomain

Each CMU contains two CMPs, and each CMP contains one twelve-core SPARC M6 processor. The number of CMUs and CMPs that are associated with a specific domain varies, depending on the type of configuration PDomain that you have on each compute server and the type of LDom configuration that you have on the PDomain.

When you first install the operating system instances on an LDom, that LDom is automatically designated as the global zone. When creating zones on Database Domains, the Database Domain is designated as the global zone. The zones created on that Database Domain are designated as nonglobal zones.

A certain number of cores are always set aside for the global zone, and the remaining cores in the Database Domain are available for the nonglobal zones (the zones in the Database Domain). The number of cores that are set aside for the global zone varies, depending on the factors mentioned previously.

The following tables provide information on the number of cores that are available for specific LDoms and zones that are created within those LDoms. See Understanding LDoms for more information on the different types of PDomain and LDom configurations.

Table 33 Cores Available for Extended Configuration PDomains (Fully-Populated DCU Configurations)

Table 34 Cores Available for Extended Configuration PDomains (Half-Populated DCU Configurations)

Table 35 Cores Available for Base Configuration PDomains (Fully-Populated DCU Configurations)

Table 36 Cores Available for Base Configuration PDomains (Half-Populated DCU Configurations)

When using the information in the tables, keep in mind that the number of cores that are set aside for the global zone applies only when you are creating nonglobal zones on that Database Domain. In that case, a certain number of cores are reserved for the Database Domain (the global zone) and the remaining cores are available for the zones on that Database Domain (the nonglobal zones). If you have a Database Domain with no zones, then all the cores are available for that Database Domain.

For each zone that you create, use a minimum of one core per zone. However, depending on the workload that you expect on a zone, a larger number of cores per zone might be preferable, thereby reducing the total number of zones in that domain. Carefully consider the expected workload on each zone that you create, so that you allot the appropriate number of cores to those zones.