Your SP system has a particular configuration defined by its frames and nodes. The SP comes with a set of predefined system partition layouts for each standard configuration. These layouts have been selected in a way which meets minimal throughput capabilities. In addition, the SP comes with the System Partitioning Aid software that allows you to construct your own layouts. If none of the predefined layouts meets your system partitioning needs, you can define your own using the System Partitioning Aid or you can submit a Request for Price Quote (RPQ) to IBM to request additional layouts. See your IBM representative for more information on the RPQ process.
Taking advantage of system partitioning is something you do by choice. However, the partitioning atmosphere is always present to some extent. In the beginning, when you have installed the PSSP software, but before you intentionally partition your system, there is one system partition that contains all of the nodes and its name is the same as the name of the control workstation. This is the default or persistent system partition. It always exists. When you choose a different partition layout, one of the resulting partitions is this default system partition. A new system partition is formed by taking nodes from existing system partitions and collecting them as a new group.
You gain several benefits from using system partitions. You can:
You can test new levels of AIX, PSSP, other IBM licensed programs, local application programs, or other software on a system currently running a production workload without disrupting that workload. Such a system partitioning solution assumes that there are spare nodes available to set aside in a test system partition. This solution lets you run migration scenarios on the test partition nodes without interfering with day-to-day operations on the rest of the system. You can form and manage system partitions and then customize the partitions with software.
You might also need to create multiple production environments with the same non-interfering characteristics as in Change management and non-disruptive migration. With system partitions these environments are sufficiently isolated so that the workload in one environment is not adversely affected by the workload in another environment. This is especially true for services whose usage is not monitored and for which there is no charge, but which have critical impact on performance of jobs, such as the SP Switch. System partitions let you isolate SP Switch traffic in one system partition from the SP Switch traffic in other system partitions.