z/OS Diagnostic Data Collection and Analysis

3.1. Diagnostic data sources

The main sources of diagnostic data are contained in the messages provided by the system in the following logs:

• Console log

  Messages sent to a console with master authority are intended for the operators. The system writes in the hard-copy log all messages sent to a console, regardless of whether the message is displayed.

• SYSLOG

  The SYSLOG is a SYSOUT data set provided by the job entry subsystem (either JES2 or JES3). SYSOUT data sets are output spool data sets on direct access storage devices (DASD). An installation should print the SYSLOG periodically to check for problems. The SYSLOG consists of the following:

  - All messages issued through WTL macros

  - All messages entered by LOG operator commands

  - Usually, the hard-copy ...