CVAF component trace

The CVAF component traces the following events:

CVAF entry and exit
All output of VTOC index I/O operations
All output of VTOC I/O performed by CVAF
All modifications of a VTOC index and space maps

CVAF captures information in ctrace format in the Device Manager address space (devman). The trace data can optionally be connected to a ctrace output writer using the component name SYSDMO. The devman buffer containing CVAF trace data is included in any system dumps that are taken by the CVAF recovery routines. In addition, the system operator can request that devman take a dump that includes the CVAF trace data. CVAF trace data provides diagnostic information that improves the first failure data capture of CVAF errors.

CVAF recording of trace events must be requested. It is not the system default. By default, no trace data is recorded by CVAF. When requesting this trace data, you can specify up to 16 job names and up to 16 ASIDs. If either the job name or ASID matches, the record will be traced. Not specifying the job name or ASID results in all records being traced. To capture CVAF trace data, enable tracing as follows:

TRACE CT,ON,COMP=SYSDMO
*07 ITT006A SPECIFY OPERAND(S) FOR TRACE CT COMMAND
R 7,OPTIONS=(CVAF1,DADSM1),END

Request all component trace records for specific job names and ASIDs as follows:

TRACE CT,ON,COMP=SYSDMO                                                   
*02 ITT006A SPECIFY OPERAND(S) FOR TRACE CT COMMAND.  
R 2,OPTIONS=(CVAF1,DADSM1,DADSM2)  
*03 ITT006A SPECIFY OPERAND(S) FOR TRACE CT COMMAND.                      
R 3,JOBNAME=(JOBA,JOBB,JOBC)
*04 ITT006A SPECIFY OPERAND(S) FOR TRACE CT COMMAND.                      
R 4,ASID=(1001,1002,1003),END

Note: To capture DADSM OSVTOC recorded records, you must add DADSM2 to the list of OPTIONS parameters.

When tracing is no longer required, it can be disabled with the following commands:

TRACE CT,ON,COMP=SYSDMO
*07 ITT006A SPECIFY OPERAND(S) FOR TRACE CT COMMAND
R 7,OPTIONS=(CVAF0,DADSM0),END

Use the following command to request a devman dump that includes the CVAF ctrace data:

F  DEVMAN,DUMP=DUMP1

To display the CVAF ctrace records use the following IPCS command:

CTRACE COMP(SYSDMO)  FULL  LOCAL

For additional information on the use of IPCS, see z/OS MVS Diagnosis: Tools and Service Aids.