DUMP

DUMP={NO          }
     {DASD        }
     {(DASD,xx-yy)}

This parameter specifies whether SYS1.DUMP data sets on direct access devices are to be made available at IPL time. SVC dump options are not included in IEASYSxx. The installation can specify the options, if it so desires, through the CHNGDUMP operator command, either in the COMMNDxx parmlib member or from the console.

When planning for dump data sets the installation should be aware the dump data sets can sometimes contain privileged data. By using protected data sets (through passwords or other security methods), the installation can limit access.

Note: You can also allow the system to create dump data sets dynamically. For details, see z/OS MVS Diagnosis: Tools and Service Aids.

Operand Descriptions:

NO

specifies that no dump data sets will be made available for SVC dump at IPL time.

Note: Dump data sets can be specified after IPL by using the DUMPDS command or by adding the DUMPDS command to COMMNDxx.

DASD

specifies that the all currently cataloged SYS1.DUMPnn data sets (if any), on permanently resident direct access volumes, are to be used. The catalog will be scanned for SYS1.DUMP00 through SYS1.DUMP99. DASD is the default if the DUMP parameter is omitted.

Note: Specifying DASD is equivalent to specifying DUMPDS ADD,DSN=ALL in the COMMNDxx parmlib member.

(DASD,xx-yy)

specifies that the currently cataloged SYS1.DUMPnn data sets (if any), on permanently resident direct access volumes, are to be used. The catalog will be scanned for SYS1.DUMPxx through SYS1.DUMPyy, where xx and yy are decimal digits in the range 00 through 99.

Note: Specifying DASD is equivalent to specifying DUMPDS ADD,DSN=(xx-yy) in the COMMNDxx parmlib member.

Indicating which dump data sets are to be used by a particular system avoids unnecessary scanning of the possible 100 cataloged dump data sets and the possibility of more than one system using the same data sets.

Examples of Valid DUMP Statements:

   DUMP=NO
   DUMP=DASD
   DUMP=(DASD,00-05)

How Dump Data Sets Are Used: Dump data sets can only reside on direct access devices. Space for direct access data sets must be pre-allocated, and the data sets must be cataloged. Eligible device types consist of any direct access device supported by the system that has a track size of at least 4160 bytes (4160 bytes equals 1 SVC dump output record).

As many as 100 dump data sets may be allocated. They must be in the form SYS1.DUMPnn, in which nn may be digits 00 to 99.

Note: Specify both primary and secondary allocations for SYS1.DUMPnn data sets. IBM® suggests using the DUMPDS ADD command in COMMNDxx and DUMP=NO in IEASYSxx to make the allocated dump data sets available to SVC dump. If you do this, MVS™ provides better diagnostic messages, which indicate which dump data sets were added, which were not added, and why.

For more information about allocating SYS1.DUMPxx data sets, see z/OS MVS Diagnosis: Tools and Service Aids .

Processing of Dump Data Sets: The status and type of each dump data set is maintained by the system. The system records the data set status as empty or full. An empty data set is available for use by the system. A full data set can be printed (and emptied), or made empty by the DUMPDS CLEAR command.

A DASD data set is empty only if the first record is an end of data record. Otherwise, the data set is considered full.

When an SVC dump is requested, an empty data set is selected and that data set is then marked as being in use. When the DUMPDS CLEAR command is issued for a dump data set, that data set is marked as being available.

When an SVC dump is requested and there are no data sets marked as being available, the system reads the first record of each data set to see if it has been emptied (printed). If so, the first record is an end of data record. When the system finds such a data set, it uses it for the requested SVC dump.

Note: Tape data sets are not supported.

Value Range: Not applicable

Default Value: DASD

Associated Parmlib Member: None