IBM System Management Facilities
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IBM SMF is a component of IBM's z/OS for mainframe computers, providing a standardised method for writing out records of activity to a file (or data set to use a z/OS term). SMF provides full "instrumentation" of all baseline activities running on that IBM mainframe operating system, including I/O, network activity, software usage, error conditions, processor utilization, etc.
One of the most prominent components of z/OS that uses SMF is the IBM Resource Measurement Facility (RMF). RMF provides performance and usage instrumentation of resources such as processor, memory, disk, cache, workload, virtual storage, XCF and Coupling Facility.
RMF is technically a priced (extra cost) feature of z/OS. BMC sells a competing alternative - CMF. RMF is the more popular of the two.
SMF forms the basis for many monitoring and automation utilities. Each SMF record has a numbered type (e.g. "SMF 120" or "SMF 89"), and operators have great control over how much or how little SMF data to collect. Records written by software other than IBM products generally have a record type of 128 or higher.
Here is a list of the most common SMF record types:
- RMF records are in the range 70 through to 79. RMF's records are generally supplemented - for serious performance analysis - by Type 30 (subtypes 2 and 3) address space records.
- DB2 writes type 100, 101 and 102 records, depending on specific DB2 subsystem options.
- CICS writes type 110 records, depending on specific CICS options.
- Websphere MQ writes type 115 and 116 records, depending specific Websphere MQ subsystem options.
SMF records are written to SMF data sets when they are created. These are then periodically dumped to sequential files using the SMF Dump Utility (IFASMFDP). IFASMFDP can also be used to split such sequential files and copy them to other files.
