Using IFASMFDP — the SMF data set dump program

When the current recording data set cannot accommodate any more records, the SMF writer routine automatically switches recording from the active SMF data set to an empty SMF data set, and then passes control to the IEFU29 SMF dump exit. The operator is then informed that the data set needs to be dumped. For more information about the IEFU29 exit, see z/OS MVS Installation Exits.

SMF data sets cannot be shared across systems. IBM® does not recommend that the SMF data set dump program be run from one system in an attempt to clear a SMF data set used by another system.

When notified by the system that a full data set needs to be dumped, the operator uses the SMF data set dump program (IFASMFDP) to transfer the contents of the full SMF data set to another data set, and to reset the status of the dumped data set to empty so that SMF can use it again for recording data.

The SMF data set dump program dumps the contents of multiple VSAM or QSAM data sets to sequential data sets on either tape or direct access devices. The SMF data set dump program allows the installation to route different records to separate files and produce a summary activity report. This report is described in Summary activity report. The job control language (JCL) to execute the SMF data set dump program is described in Running the SMF data set dump program.

The SMF data set dump program copies the input data sets to the output data sets. During the copy process, the SMF data set dump program creates two SMF records and writes them to every output data set: a dump header (record type 2) at the beginning of the data set and a dump trailer (record type 3) at the end of the data set.

If problems are encountered, the SMF data set dump program writes messages, as required, to the SYSOUT data set. The messages describe the following problems:
  • The operator must not clear a data set that is being filled. If the operator attempts to clear the active SMF data set, the SMF data set dump program returns a code of X'08' in register 15. The operator can, however, dump the active or alternate data set without clearing it.
  • If the SMF data set dump program is unable to open either the input or output data sets, it writes an error message indicating which data set was not successfully opened.
  • If all SMF data sets and the SMF buffers become full, SMF will be in a data lost condition (unable to record) until dumping takes place. When this condition occurs, SMF tracks the number of lost records in record type 7 and the operator receives a message stating that data is being lost.

The SMF data set dump program writes a message to the SYSPRINT data set for all input and output data sets and includes the names of the data sets in the message.