The following list contains some general information about SMF
records.
- To write any SMF-formatted records (except record types 2, 3,
and 7) to the SMF data set, specify the ACTIVE parameter. To write
record type 17 for temporary data sets, specify REC(ALL).
- The method of entry to a particular SMF record type determines
whether installation-exit routine IEFU83, IEFU84, or IEFU85 receives
control before control is returned to the caller of the SVC routine.
A branch entry by a cross-memory caller causes IEFU85 to receive control.
A branch entry by a non-cross-memory caller causes IEFU84 to receive
control. An SVC 83 call causes IEFU83 to receive control.
- Many current SMF records contain variable sections. The user of
these records should be aware that the record pointers must be updated
by the length of each variable section of the record when the record
data is being manipulated. Failure to do the address calculation will
result in writing over valid data in previously processed sections.
Other SMF records, (types 23, 30, 32, and 90), contain offsets that
point directly from the record header to the data section.
- Unless otherwise specified, all EBCDIC fields within the SMF records
are left-justified and right filled with blanks.
- Detailed information about the device type and device class, within
a record, can be found in z/OS® MVS™ Data Areas in z/OS Internet library.
- In JES2 and JES3 records, information found in the ‘Common Section’
and the ‘Identification Section’ is defined in JESPARMS.
- In a loosely-coupled multiprocessing environment (such as JES2
shared spool or JES3), it is possible for the job START/LOGON time
to be greater than the STOP/LOGOFF time because the installation does
not synchronize the CPU clocks. The difference occurs when the START/LOGON
time is initialized on processor A and the job is then processed on
processor B. The STOP/LOGOFF time is recorded from processor B.
- SMF records created by IBM® components
never exceed 32,756 bytes. If the data required in a record causes
the record to exceed that length, the component responsible for creating
the record can, instead, create multiple (continuation) records, none
of which exceed 32,756 bytes. See Record Type 22 (16) — Configuration for
an example that uses a continuation section and Record Type 24 (18) — JES2 Spool Offload for
an example that uses bit mapping to indicate continuation.
- SMF records are written as spanned (VBS) in order
to conserve storage space by ensuring that each block of data is as
full as possible. If you specify DCB parameters on any of the input
or output DD statements for IFASMFDL, you must specify RECFM=VBS.
- You should not specify LRECL=X for reading or writing
SMF dump data, because LRECL=X signifies that a single record may
be larger than 32,756 bytes, which is not the case for SMF data.
- You can specify LRECL=32760 instead of 32767. You
can also specify any block size from 4096 to the maximum allowed for
the chosen device.