6. DATA SOURCES › 6.8 PR/SM LPAR Concepts › 6.8.5 Data Analysis › 6.8.5.2 LPAR Level Analysis › 6.8.5.2.1 General Purpose LPA/Rs › 6.8.5.2.1.1 z/OS LPARs Without Specialized Processors

6.8.5.2.1.1 z/OS LPARs Without Specialized Processors

If a z/OS logical partition does not use any zAAP, then the
only type of CPU resources it can consume comes from the
standard CP pool of processors of the CPC.  Your ability to
accurately track its utilization depends on two key factors:
does it use shared or dedicated processors, and is the wait
assist facility enabled?

Shared Standard CP Processors
-----------------------------

If the LPAR is configured with shared standard CP processors
and wait assist is disabled (Wait Completion = No), the time
the logical processors are dispatched, from PR/SM management
routines, is equal to the actual busy time as seen from
inside the LPAR.  In other words, the value of LPCTODTM in
the HARLPC file is the same as CPUTODTM as well as CPUTOBTM
in the HARCPU file.

Although, in theory, you could choose to report from either
the HARCPU or the HARLPC files, we recommend you use the
HARLPC file measurements.  The main reason for this is that
the HARCPU file will only contain information for logical
partitions running RMF and whose SMF type 70 subtype 1
records are processed by CA MICS.  For example, the HARCPU
file should not be used for non z/OS LPARs, or if you input
to CA MICS the SMF records from only one of your z/OS LPARs.
This problem does not apply to the HARLPC file because, as
long as one or more logical partitions has its SMF type 70
subtype 1 records processed by CA MICS, it will contain
information about all LPARs defined in the configuration.

However, care must be taken when using the HARLPC file
because, if multiple z/OS systems are active in the complex,
each one can record the activity of the others.  It is
therefore necessary to select only one system (SYSID) from
the HARLPC file, in order to avoid data duplication.  We
recommend that you select the SYSID that is most often active
during the day.  If you have 3 LPARs defined and one is a
production machine that will be active all the time, and the
other 2 are test machines that come up and down, use the
production machine's SYSID.

Listed below are examples for your shared LPARs analysis:

o To know how much of its allocated CPU resources an LPAR
  consumed, use the following data element from the HARLPC
  file:

  LPCPCVPU - LPAR CP Processors Utilization

o To know how many of the resources of the pool of standard
  CP processors were used by one LPAR, use the following data
  element from the HARLPC file:

  LPCPCTSU - LPAR Total CP Processors Utilization

  Note:  If all processors from the standard CP pool are
  shared, this element is equal to LPCPCSSU (LPAR Shared CP
  Processors Utilization).

Dedicated Standard CP Processors
--------------------------------

When the logical processors of an LPAR configured with
dedicated standard CP processors are dispatched, the
resources they use are unavailable for other use whether they
are actually executing instructions or are in the wait state.
From PR/SM perspective, the dispatch time is equal to the
measurement interval time, regardless of actual processor
utilization, and the LPAR appears as being used 100% of the
time in the HARLPC file.

In order to determine the actual utilization, the total time
in seconds that the logical processors were not busy (wait
time) must be subtracted from the total dispatch time.
Since this wait time is not available in the HARLPC file,
dedicated LPARs' utilization must be tracked from the HARCPU
file.  However, in regards to the amount of total CPU
resources allocated to these LPARs, and thus unavailable to
others, you can still use information from the HARLPC file.

Listed below are examples for your dedicated LPARs analysis:

o To know how much of its allocated CPU resources an LPAR
  consumed, use the following data element from the HARCPU
  file:

  CPUPCBSY - Pct CP Processors Busy

o To know how many of the resources of the pool of standard
  CP processors were dispatched to one LPAR, use the
  following data element from the HARLPC file:

  LPCPCTSU - LPAR Total CP Processors Utilization

Wait Assist Enabled
-------------------

When the Wait Assist function is enabled, it indicates that
the LPAR's logical processors remain dispatched until the end
of the user-specified interval, called time slice, even when
they are in the wait state. In this case dispatch time
includes wait time.

Dedicated LPARs do not use the wait-assist feature because
they are dedicated to specific physical processors and have
them whether or not they wait.

Shared LPARs are where the wait-assist feature comes into
play.  As for dedicated LPARs, if the feature is enabled,
although you can still use the information from the HARLPC
file to get the amount of total CPU resources allocated to
such an LPAR, you must look into the HARCPU file to get the
actual LPAR utilization.

o To know how much of its allocated CPU resources an LPAR
  consumed, use the following data element from the HARCPU
  file:

  CPUPCBSY - Pct CP Processors Busy

o To know how many of the resources of the pool of standard
  CP processors were dispatched to one LPAR, use the
  following data element from the HARLPC file:

  LPCPCTSU - LPAR Total CP Processors Utilization