Reference Guide › Performance Metrics › CA IBM LPAR Performance Metrics › Processor Pools Support › CPU Metrics › Capacity Metrics

Capacity Metrics

Shared-processor pools provide control of the processor capacity that a specific set of partitions can consume from the physical shared-processor pool. Each partition within a processor pool is guaranteed its processor entitlement. The uncapped partitions may be allocated additional capacity from the reserved pool capacity. If some partitions in a processor pool do not use their capacity entitlement, the unused capacity is ceded. Other uncapped partitions within the same pool are allocated the additional capacity according to their uncapped weighting. The following metrics characterize the utilization of the processor capacity within a shared-processor pool:

Entitled pool capacity

Represents the sum of the entitlement capacities of the partitions in the shared-processor pool plus the reserved pool capacity.

Available pool capacity

Indicates the available physical processors (app) in the shared pool, that is, the unused part of the shared pool.

Example: The relation between available physical processors and the CPU utilization

The "lparstat" command shows the available physical processors (app) in the shared pool. The lparstat command can be run from any logical partition that has enabled the shared processor pool utilization authority. The size of the shared pool is 8 CPUs (psize). The available processors for each sample interval are shown under the "app" column. System configuration is as follows: type=Shared, mode=Uncapped, smt=4, lcpu=4, mem=1024 MB, psize=8, ent=0.10. For the value of 7.92 available processors, the CPU utilization is 1.0 percent and is calculated as follows: ((8.0 - 7.92) / 8.0).