The display tells the operator to use the DISPLAY TRACE command to obtain status for system and component trace.
Remember: Supply a reasonable value to the nnnM or nG parameter after considering the available central storage and the actual storage required for system trace. Supplying a large value for nnnM or nG might cause a shortage of pageable storage in the system.
If you omit the nnnM or nG parameter, the system assumes 1M for each processor, or the size established by the last TRACE command that specified a table size during the IPL. If the value specified exceeds a system determined safe amount, the command will be rejected and message IEA135I will display the maximum amount allowed per processor. The maximum value depends on real frame usage at the time the TRACE command is issued, and can vary each time the TRACE command is issued.
Restriction: You cannot specify the BR= parameter if you specify ST=OFF.
You can run the SYSTRACE_BRANCH check to make sure that your installation does not run with BR=ON for longer than desired. See SYSTRACE_BRANCH in IBM Health Checker for z/OS User's Guide.
Restriction: You cannot specify the MODE= parameter if you specify ST=OFF.
You can run the SYSTRACE_MODE check to make sure that your installation does not run with MODE=ON for longer than desired. See SYSTRACE_MODE in IBM Health Checker for z/OS User's Guide.
Remember: Supply a reasonable value to the BUFSIZE parameter after considering the available central storage and the actual storage required for system trace. Supplying a large value for BUFSIZE can cause shortage of pageable storage in the system.
After you enter a TRACE CT,WTRSTART command, you should turn the trace on and connect the writer with a WTR parameter in the reply for a TRACE CT command or in a parmlib member, if specified.
If the WTRSTART parameter on the CTncccxx parmlib member or TRACE CT command specifies NOWRAP, the system uses the primary and secondary extents of the data set or sets. If the WTRSTART parameter specifies WRAP or omits the parameter, the system uses only the primary extent or extents.
If you specify or default FLUSH, the writer will stop when it has finished writing out its current buffers. If you specify NOFLUSH, the writer stops immediately.
If the trace is not turned off or disconnected from the writer, message ITT121I informs the operator of the condition and the writer will not stop.
Whenever a trace that has sublevel traces is changed, all sublevel traces currently in the LIKEHEAD state will also be changed. Therefore, a change may cascade down a number of levels.
A head trace may have been defined so that it is not allowed to be changed (HEADOPTS=NO on the CTRACE DEFINE macro). If this is the case, the trace is really just a place holder for options for other traces.
nnnnK is the buffer size in kilobytes, where nnnn is a decimal number from 1 to 9999. nnnnM is the buffer size in megabytes, where nnnn is a decimal number from 1 to 2047.
When the size is not specified, the system uses the component-defined default or the size specified in a CTncccxx parmlib member.
The size specified for an installation-supplied application trace must be within the range specified on the CTRACE DEFINE macro for the trace; see the programmer for the size value.
Some components do not turn tracing completely off. Instead, they reduce the tracing activity to the minimum required for serviceability data in a dump. If the CTRACE DEFINE macro that defined the trace specified the MINOPS parameter, tracing is reduced to a minimum and component trace writes a message to the operator.
If a component level trace has sublevel traces that are defined with the LIKEHEAD parameter on the CTRACE DEFINE macro, the sublevel traces will either be reduced to the minimal tracing or turned off, in the same manner as their head level component trace.
The SUB parameter is limited to a single subname; multiple subnames are not supported.
If the sublevel trace name contains any national characters ($ # @), you must enclose the name in quotation marks. Otherwise, quotation marks are not required. In all cases you may specify the alphabetic characters in upper or lower case.
If subname is a head level, all of the head's sublevel traces that are defined with a LIKEHEAD=YES parameter inherit the options specified in the reply to this command. Therefore, the options you specify for a head level can affect many sublevel traces.
Omitting the SUB parameter for a head level that is defined with HEADOPTS=YES affects all sublevel traces with the LIKEHEAD attribute.
Any option specified on the TRACE command overrides the option specified in the parmlib member.