Logical Partitions - Uncapped Processors
The following scenario explains how uncapped partitions can exceed their current processing capacity when the shared processor pool has unused processing power.
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 that 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. The number of processing units that the partition can use is limited by the virtual processor settings.
Partition 1 is assigned 1.00 processing units and is running at 100% utilization. The partition could use more resources, but the partition is in capped mode and cannot access unused processing resources in the shared processor pool.
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 3 now has more activity and is using all of its assigned resources.
Partition 3 is now running at 100% utilization and is in need of more processing resources.
Partition 2 is not using all of its processing resources making 0.25 processing units available.
Partition 2 now needs more processing resources to complete a task.
The processing units distributed to partition 3 automatically return to partition 2, providing enough processing resources to complete the task.