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Fall COMMON and Past Blog Entries

September 26, 2012

This week, I've been busy with Fall COMMON and haven't had time to write a new blog article. In the absence of a new blog this week, I wanted to recommend that if you haven't read some of the past blogs, you should. Some of the early ones published in the fall of 2009 are still very pertinent and of interest.

One example is the ability to Display CPU Utilization for All Partitions, which is republished here this week:

i Can .... Display CPU Utilization for all Partitions 

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.

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. Then, 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. The CPU utilization information collected will reflect work done in partitions running AIX and Linux as well as IBM i, but AIX and Linux don’t support collecting this data. Only IBM i has this data collection capability.

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 in a file named QAPMLPARH

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:


If you’re on POWER6 hardware, but have not yet installed IBM i 6.1, you may want to think about creating a small i partition and experimenting with this new capability to manage your machine's processor utilization across all partitions.


Posted September 26, 2012| Permalink