The z/OS operating
system issues messages from z/OS elements
and features, and from program products and application programs running
on the system. The system issues messages in different ways and to
different locations:
- WTO and WTOR macros: Most messages are issued through WTO
and WTOR macros to one of the following locations:
- Console
- Operations log(OPERLOG)
- System log (SYSLOG)
- Job log
- SYSOUT data set
Routing codes determine where the messages are displayed or printed. The routing codes for messages issued by the operating system are included with each message.
- WTL macro or the LOG operator command: Some messages are issued through the WTL macro or the LOG operator command to the system log (SYSLOG).
- Dumping services routines: Dump messages are issued through
the Dumping services routines and can appear in one of the following
locations:
- SVC dumps, stand-alone dumps, or SYSMDUMP ABEND dumps formatted by the interactive problem control system (IPCS)
- Trace data sets formatted by the interactive problem control system (IPCS)
- ABEND dumps or SNAP dumps produced by the dumping services
- DFSMS/MVS access methods: Some messages are issued through
DFSMS/MVS access methods directly to one of the following locations:
- Output data set
- Display terminal
Messages are sent to different locations to meet some specific
needs. For example, messages routed to a console usually shows the
result of an operator command and sometimes require an operator reply,
while messages recorded in the hardcopy log permanently are often
used for auditing. Understanding the locations where you receive messages
can help you manage your message flow.
- Console
- Messages sent to a multiple console support (MCS) console, an
SNA multiple console support (SMCS) console, an extended MCS (EMCS)
console,
or an HMC multiple console support (HMCS)
console
are intended for the operators. Operations can control
which messages are displayed. See z/OS MVS Planning: Operations for
information about controlling message display. The system writes in the hard-copy log all messages sent to a console, whether the message is displayed or not.
- Operations log
- The operations log (OPERLOG) records all message traffic from
each system in a sysplex that activates the OPERLOG. The operations
log consists of the following data:
- Messages to and from all consoles
- Commands and replies entered by the operator
- System log
- The system log (SYSLOG) is a SYSOUT data set that stores the messages
and commands from the current system. SYSOUT data sets are output
spool data sets on direct access storage devices (DASD) provided by
the job entry subsystem (either JES2 or JES3). An installation usually
prints the system log periodically. The system log consists of:
- All messages issued through WTL macros
- All messages entered by operator LOG commands
- Usually, the hard-copy log
- Any messages routed to the system log from any system component or program
- Job log
- Messages sent to the job log are intended for the programmer who submitted a job. The job log is specified in the system output class on the MSGCLASS parameter of the JCL JOB statement.
- SYSOUT data set
- Messages sent to a SYSOUT data set are intended for a programmer. These messages are issued by an assembler or compiler, the linkage editor and loader, and an application program. If the SYSOUT data set and the MSGCLASS parameter on the JCL JOB statement specify the same class, all messages about a program will appear in the same SYSOUT listing.