I completely missed the birthday of my blog. I started 3 years ago - on February 6, 2013. In between I posted more than 650 blog entries and got good feedback.
Today I have a technical topic:
In the past I had several blog entries related to the Attention Routine (AR) command SIR (System Information Report). Just use the tag "sir" and use "Find a tag" on your right to locate such blog entries.
With SIR HELP you can list all possible parameters. So far I discussed the CPU information, the I/O counts, the latest APAR information, ... of the SIR output.
Today I want to give some more details about the Logical-Partition Capability Adjustment Factor (Cap.).
The red arrow in below picture marks the SIR output line, that displays the configured CPU count which is further subdivided into the dedicated CPU (Ded.) and shared CPU (Shr.) counts and the Logical-Partition Capability Adjustment Factor (Cap.).
"Cap" specifies the amount of the underlying level-1-configuration CPU capability that is allowed to be used for this level-2 configuration (z/VM or z/VSE in LPAR) by the LPAR hypervisor.
It represents the maximum capacity available to the LPAR, compared to the capacity of the CEC, based on the CEC's total number of shared CPUs. The factor is displayed as a percentage value.
The factor calculates as the minimum of the following:
- number of online shared CPUs in LPAR divided by number of shared CPUs in CEC.
- LPAR Weight divided by Total Weight, if Initial Capping is enabled for the LPAR - defined in the LPAR configuration panel of the Hardware Management Console (HMC). The Total Weight is the sum of the weights of the active LPARs.
- Absolute Capping value of the LPAR divided by number of shared CPUs in CEC, if an Absolute Capping value is specified for the LPAR.
- Absolute Capping value of the LPAR group divided by number of shared CPUs in CEC, if an Absolute Capping value is specified for the LPAR group to which the LPAR belongs to.
Example: LPAR has 2 online shared CPUs and an LPAR Weight of 90, CEC has 10 shared CPUs, Total Weight of all active LPARs is 600.
- Without any capping: Cap. = 20% (2 / 10)
- With Initial Capping enabled: Cap. = 15% (90 / 600)
- With Absolute Capping of the LPAR set to 1.00: Cap. = 10% (1.00 / 10)
- With Absolute Capping of the LPAR Group set to 0.50: Cap. = 05% (0.50 / 10)
You will also find this description in the upcoming "Hints and Tips for z/VSE 6.1" book. It will be available soon on our z/VSE documentation page. I will keep you posted, when it is there.