Using SMF Record Type 99

SMF record type 99 provides detailed audit information for work run on z/OS®. You can use the type 99 records for analyzing the performance characteristics of work. The records contain performance data for each service class period, a trace of SRM actions, the data SRM used to decide which actions to take, and the internal controls SRM uses to manage work. This can help you determine in detail what SRM is doing to meet your work's goals with respect to other work, and the types of delays the work is experiencing.

You should write SMF type 99 records only when you want this detailed information. For general reporting and tuning information for a system, you can use SMF type 72 records.

SRM writes type 99 records for each policy interval, or approximately once every 10 seconds.

There are the following type 99 record subtypes:

Subtype 1

Contains system level data, the trace of SRM actions, and data about resource groups. A subtype 1 record is written every policy interval.

Subtype 2

Contains data for service classes. A subtype 2 record is written every policy interval for each service class if any period in the service class had recent activity.

Subtype 3

Contains service class period plot data. A subtype 3 record is written every policy interval for each service class if any period in the service class had recent activity and plot data.

Subtype 4

Contains information about a device cluster. A device cluster is a set of service classes that compete to use the same DASD devices. A subtype 4 record is written every policy interval for each device cluster in the system.

Subtype 5

Contains data about monitored address spaces. A subtype 5 record is written each policy interval for each swapped in monitored address space.

Subtype 6

Contains summary information about each service class period, including the resource control settings for the next policy interval. A subtype 6 record is written each policy interval.

Subtype 7

Contains summary information for the Enterprise Storage Server® (ESS) with Parallel Access Volume (PAV) feature. A subtype 7 record is written every third policy interval.

Subtype 8

Contains summary information for LPAR CPU management. A subtype 8 record is written each policy interval, when in LPAR mode.

Subtype 9

Contains summary information for dynamic channel path management. A subtype 9 record is written each policy interval.

Some fields are used as input to adjust the policy. Those fields contain the data collected during the policy interval just prior to policy adjustment. Other fields are altered when the policy is adjusted. Those fields contain the data resulting from the policy adjustment. For example, a service class period dispatch priority field contains the dispatch priority for the next policy interval not the dispatch priorities from the previous policy interval.