iCan Blog Archive

In last week’s blog, I mentioned that with the latest Performance Data Investigator enhancements, IBM i now provides physical system charts that display the overall CPU utilization for the physical box and all partitions, regardless of operating system.

This is an exciting enhancement that many of our customers have asked for, so I want to tell you more about it and how you enable this feature.

Many IBM i customers are using logical partitioning with their systems. When using multiple partitions, many customers want to understand the overall utilization of their processing capability, across all partitions, regardless of whether the partition is running IBM i, AIX or Linux. To do this, many have created their own customized solutions by querying Collection Services data from each partition and pulling together an overall view of CPU utilization; but if you have AIX or Linux partitions, there’s missing information unless you have the skills to collect and understand the performance data from those partitions as well.

Starting with POWER6 hardware and IBM i 6.1, you’ve been able to collect CPU utilization information for the physical system since firmware level xx340_061 was introduced late last year. However, that just enabled the collection of the data; IBM provided no way to view it. With the updates to the Performance Data Investigator I reviewed last week, additional charts are now available for Physical System views of CPU utilization that now let you easily view this data.

However, there are some specific configuration requirements. As I’ve already said, you must be running on POWER6 hardware with a minimum firmware level of xx340_061. You also must be using the IBM i 6.1 release or later.

You must also enable the collection of this performance data for the desired partition. You only need to collect this data on one partition and it must be an IBM I partition if you want to view the data with the Investigate Data task. The CPU utilization information collected will reflect work done in partitions running AIX and Linux as well as IBM i.

To enable 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’s 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. It’s not quite as simple with IVM; if you’re using IVM, you use the lssyscfg command, specifying the all_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 files QAPMLPARH and QAPMSYSPRC

The latest update to the Performance Data Investigator includes additional perspectives in the Collection Services content package for this data in a folder called “Physical System.” It also includes the following charts:

  • 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

Here’s an example of the Logical Partitions Overview chart, which shows configuration data and CPU utilization for all logical partitions on the system:

Logical Partitions Overview
Logical Partitions Overview

You can read more about this feature in Collecting and displaying CPU utilization for all partitions.

This blog post was edited for currency on January 26, 2020.

This blog post was originally published on IBMSystemsMag.com and is reproduced here by permission of IBM Systems Media.