Logical Partitions - Capped Processors
The following scenario explains how unused resources in a capped partition are used by uncapped partitions in the shared processor pool.
Server firmware is the code that resides in system flash memory. Server firmware includes a number of subcomponents, one of them being the logical partition firmware.
The shared processor pool is a group of physical processors that provide processing capacity that can be shared among multiple logical partitions.
In this example we have three logical partitions on the server.
Partition 1 is using the capped mode. This means the logical partition can never exceed its assigned processing capacity.
Partition 2 and 3 are using the uncapped mode. This means that the logical partitions can exceed their assigned processing capacity when the shared processor pool has any unused processing power.
Partition 1 is assigned 1.00 processing units and is running at 99% utilization.
Partitions 2 and 3 have been assigned 0.50 processing units each and are using only 50% of their assigned resources (0.25 processing units each).
Partition 1 is not using all of its processing resources. The unused processing resources from partition 1 will be used by the uncapped partitions in the shared processor pool.
Partition 2 and 3 now have more activity and are using all of their assigned resources.
Partition 3 is now running at 100% utilization and needs more processing resources.
Processing units from partition 1 are now used by partition 3, ensuring all activity is processed. The processing units from partition 1 are still committed to partition 1 and can be taken from partition 3 at any time.
The processing units now return to partition 1 when they are needed. However, partition 1 cannot use more processing units than those that are committed to partition 1.