Examples of traces

This information shows examples of traces you can do.

Starting a trace while Download for z/OS is running

To obtain a full external trace and direct the trace data to a Generalized Trace Facility (GTF) data set, follow this procedure:

Start GTF, requesting USR records of type FD0 and FD4.
In the Download for z/OS startup procedure, specify PARM=(,INTR) on the EXEC statement and TRACE=YES on the PRINTDEV statement for the FSA you want to trace so that you obtain an internal trace that starts at FSS initialization. These are the default values, so you can omit the PARM parameter and the TRACE parameter. For information about tracing parameters in the startup procedure, see Startup procedure JCL statements.
Start the Download for z/OS FSA.
Enter this PSF operator interface command to start a full external trace:
```
MODIFY fss_name,TRACEON,fsa_name,FORMAT=GTF,MODE=FULL
```
where fss_name is the name of the Download for z/OS FSS, and fsa_name is the name of the FSA you want to trace.
Run the failing job.
Enter this PSF operator interface command to end the trace:
```
MODIFY fss_name,TRACEOFF,fsa_name
```
where fss_name is the name of the Download for z/OS FSS, and fsa_name is the name of the FSA.
Stop GTF.

Starting a trace at initialization of Download for z/OS

To obtain a full external trace that begins during the startup procedure for Download for z/OS and direct the trace output to a PSF trace data set or zFS file, follow this procedure:

In the Download for z/OS startup procedure, specify TRACE=YES on the PRINTDEV statement for the FSA you want to trace so that tracing starts during FSS initialization. TRACE=YES is the default, so you can omit the TRACE parameter. For information about tracing parameters in the startup procedure, see Startup procedure JCL statements.
In the startup procedure, include a DD statement to allocate a PSF trace data set or zFS file. The name of the DD statement must match the name of the FSA to be traced. For more information, see Allocating a PSF trace data set or zFS file.
For some problems, IBM® support might ask you to also include a DD statement to allocate an FSS trace data set or zFS file (also called an NST trace data set or zFS file). Specify the name of the DD statement in the PARM parameter, as shown in Step 4. For more information, see Allocating an FSS trace data set or zFS file.
In the startup procedure, specify the PARM=(,FULL) parameter on the EXEC statement:
```
//stepname EXEC PGM=APSKAFPD,PARM=(,FULL)
```
If you allocated an FSS trace data set or zFS file, also specify the name of the DD statement for the data set or file:
```
//stepname EXEC PGM=APSKAFPD,PARM=(FSSddname,FULL)
```
where FSSddname is the name of the DD statement for the FSS trace data set or zFS file.
Run the failing job.
Enter this PSF operator interface command to end the trace:
```
MODIFY fss_name,TRACEOFF,fsa_name
```
where fss_name is the name of the Download for z/OS FSS, and fsa_name is the name of the FSA.

Note: Download for z/OS does not require a PRINTDEV statement to work correctly. Download for z/OS works correctly with just the following 2 statements in the writer procedure:

//PRT01    CNTL
//PRT01    ENDCNTL

However, the full external trace for Download for z/OS is truncated if only those 2 statements exist for PRT01. You need the PRINTDEV statement as well for the trace to be complete. The following is needed for the trace to be complete, as in this example:

//PRT01    CNTL
//PRT01    PRINTDEV
//PRT01    ENDCNTL