RMFOM0 - Monthly LPAR MSU Use and Capacity Limits
The RMFOM0 inquiry shows the monthly z/OS LPAR MSU use at the ZONE (Time Zone) level.
micsrm140
All z/OS LPARs are accounted for. For each ZONE within each month, three vertical bars show the minimum, average, and maximum MSU use in the time range. The inquiry generates two separate files. One for z/OS LPARs that have defined capacity limits, and the other for z/OS LPARs with no defined capacity limits. One of the uncapped LPARs for each CPC is the PHYSICAL LPAR that captures PR/SM overhead.
The inquiry produces a clustered vertical bar chart where one bar represents the average number of consumed MSUs, one bar represents the minimum number of consumed MSUs and another bar represents the maximum number of consumed MSUs.
The example shows the minimum, average, and maximum MSU usage chart for a z/OS LPAR (PRSMLPNM=’SYSE’) running on an IBM zEC12 2287-615 CPC. Four ZONES have been defined to
MICS
. The title of the chart specifies the day and time ranges that are associated with each ZONE.
Uses
The processing capacity of mainframe CPCs is expressed in MSUs (Millions of Service Units per Hour). One of the characteristics of a specific CPC model is its MSU capacity. This capacity is indicative of its workload processing capability and is directly related to the number of general-purpose CP engines configured. Each LPAR that is assigned logical CP processors uses some amount of the available CPC MSUs. The MSU capacity of a CPC and of individual LPARs can influence the cost of software licensed to run on LPARs. Some software licensing costs can be lowered by defining a capacity limit for an LPAR. The limit prevents the LPAR from using the full MSU capacity associated with the logical processors assigned to it.
The RMFOM0 charts are useful for visualizing longer term resource usage trends for your z/OS LPARs. The average MSU usage bar is the most important. The MIN and MAX represent singular extremes, while the average MSU use is the average of all RMF intervals over each time period charted.
Charts
Monthly MSU Use for Capped LPARs
All LPARs in this data extract have defined capacity limits. If no LPARs in any CPCs have defined capacity limits, a single chart is produced with a CPCID of ‘NO Capped LPARS’ and an LPAR name of ‘NADA.’

Left Y-axis
LPCMNMSU
Avg Number of Consumed MSUs
LPCUAVMSU
Avg Number of Consumed MSUs
LPCMXMSU
Avg Number of Consumed MSUs
LPCDEFLM
Partition Defined Capacity Limit
X-axis
YYYYMMZZ
Year : Month : Zone
Data element YYYYMMZZ is derived by concatenating the 4-digit year, colon ":", and 2-digit month, with the literal " - Zone ", and the 1-digit ZONE value (for example, 2010:08-Zone 1).
Monthly MSU Use for Uncapped LPARs
All LPARs in this data extract have no defined capacity limits. There is always at least one LPAR in this data extract for each CPC -- the ‘PHYSICAL’ LPAR which shows PR/SM overhead.

Left Y-axis
LPCMNMSU
Avg Number of Consumed MSUs
LPCUAVMSU
Avg Number of Consumed MSUs
LPCMXMSU
Avg Number of Consumed MSUs
X-axis
HHMM
Hour : Minute
Data element YYYYMMZZ is derived by concatenating the 4-digit year, colon ":", 2-digit month, with the literal " - Zone ", and the 1-digit ZONE value (for example: 2010:08-Zone 1).
Inquiry Defaults
- HARLPC at the MONTHS timespan file: Cycles 00 - 06
- Filters: PRSMLPTP EQ ‘CP’ or ‘PHYSICAL’ (Only CP using LPARs or PR/SM overhead (PHYSICAL)
- Derivations:
CPCID
%CPCID ;
YYYYMMZZ
PUT(YEAR4,Z4.) || ':' || PUT(MONTH,Z2.) || '-Zone ' || SUBSTR(ZONE,1,1);
Modifications
Modification considerations:
- You can increase or decrease the number of cycles to look at more or few months.
- You can use a filter statement to restrict data to focus on a particular time zone (for example, ZONE EQ 1).
- Using the following CPC Identification data elements, you can filter on CPC:
- fffMOD - Processor Model Family (where fff is the file identifier -- for example., CPU, LPC, and so on.)
- CPCMODID - CPC Model Identifier
- CPCSEQNB - CPC Sequence Number
- If you want to focus exclusively on the important Average MSU use value, you can remove the MIN and/or MAX MSU use data elements from the chart display.