Collecting and displaying CPU utilization for all partitions

When using multiple partitions, it can be important to understand the overall utilization of processing capability, across all partitions, regardless of whether the partition is running IBM® i, AIX®, or Linux®. IBM i provides a way to collect and display this data.

Collecting the data

To collect CPU utilization for the physical system, you must meet the following configuration requirements:

  • POWER6® hardware with IBM i 6.1 and a firmware level of xx340_061 or later.
  • Enabled the collection of performance data for the partition you want it collected on. You only need to collect this data on one partition, and this partition must be an IBM i partition. The CPU utilization information that is collected will reflect work done in partitions that are running AIX and Linux as well as IBM i, but AIX and Linux do not support collecting this data.

    Enabling the collection of this performance data requires the setting of a configuration parameter on the HMC or Integrated Virtualization Manager (IVM). On the HMC, there is an "Allow performance information collection" checkbox on the processor configuration tab. Select this checkbox on the IBM i partition that you want to collect this data. If you are using IVM, you use the chgsyscfg command, specifying the allow_perf_collection (permission for the partition to retrieve shared processor pool utilization) parameter. Valid values for the parameter are 0, do not allow authority (the default) and 1, allow authority.

Once the performance data collection support is enabled, Collection Services will collect this additional information. At each collection interval, Collection Services will collect partition configuration and utilization information from the hypervisor. The data is stored in the Collection Services database file QAPMLPARH. You also have the ability to get physical processor utilization in the Collection Services database file QAPMSYSPRC.

Displaying the data

You can use the Performance Data Investigator tool found in IBM Navigator for i to view the data collected graphically on the web. These charts can be found in the "Physical System" folder under the Collection Services content package. Some examples of charts using this data are:

  • Logical Partitions Overview
  • Donated Processor Time by Logical Partition
  • Uncapped Processor Time Used by Logical Partition
  • Physical Shared Processor Pool Utilization
  • Physical Processors Utilization by Physical Processor
  • Dedicated Processor Utilization by Logical Partition
  • Physical Processors Utilization by Processor Status Overview
  • Physical Processor Utilization by Processor Status Detail