When using multiple LPARs on a single Power System, it can be important to understand the overall utilization of processing capability, across all LPARs in the shared processor pool. Utilization data can be viewed from the LPARs using the
lparstat command. However, for this to work, the LPAR properties must be configured appropriately.
Collecting the Data
Enabling the collection of this performance data requires the setting of a configuration parameter on the HMC for the LPAR. On the HMC, there is an ‘Allow performance information collection’ checkbox on the processor configuration tab. Select this checkbox on the LPAR that you want to collect this data.
Displaying the Data
You can use the
lparstat command from the AIX command line to view the data collected. For example, if the LPAR is not configured to collect shared processor pool statistics, the
lparstat command will not show the ‘available physical processors in the shared pool’ (app) column in its output, as shown below:
On the HMC, we need to change the properties of the LPAR (in this case nim2) so that we can view the app data. To do this we click on the LPAR name from the LPAR view on the HMC, as shown below.
Once the ‘Partition Properties’ box appears, we select ‘Hardware.’ As shown in the following image, on the ‘Processors’ tab, the ‘Allow performance information collection’ box is not checked by default.
We check the box and then click on OK.
On the nim2 LPAR, we run the
lparstat command again and we find that the app column is now displayed in the output as desired. Based on this output we can easily determine that of the 16 processors in the shared pool (psize=16), 15 processors are still available for use. Essentially, the processor pool has plenty of available CPU capacity.
You may also wish to refer to the following articles for other methods of monitoring shared processor pool usage:
Chris Gibson is an AIX enterprise systems engineer for Southern Cross Computer Systems. Follow him on Twitter: @cgibbo.