Preface[edit | edit source]
Beginning with MVS through OS/390 to z/OS the "IBM System Management Facilities (SMF)" allows us to store both hardware und software diagnostic data into so called SMF Records. SMF Records are organized as VSAM Datasets. There are many numbered SMF record types organized in different data structures containing distinct diagnostic data values in the appropriate record fields. The SMF record types are numbered in the range between 0 to 255 whereby the range 0 to 127 is reserved for IBM products. Independent Software Vendor products may use record types between 128 and 255 for their diagnostic data. The different record structures and fields of the IBM reserved record types are described in "z/OS MVS System Management Facilities (SMF)" (see L11 or L12 ). Descriptions of other record types apply to the appropriate Independent Software Vendors.
Although almost all questions regarding historical behavior of mainframe usage could be satisfied by using the diagnostic data within the SMF records, it is considered very difficult to extract the appropriate data. In the spring of 2013 George Ng published a wonderful series of articles (a1, a2, a3, a4) in "IBM Systems Magazine" showing how easy it is to pick almost any value out of SMF record fields using the REXX language (see also References).
But although there are a few fields with directly useable, useful values in the SMF records most of the data contained needs to be combined in more or less complicated formulas to produce more meaningful content.
That is the intention of this book. The first chapter describes how to extract SMF record field values using REXX. The remaining chapters are intended to be a growing collection of formulas from the community for the community, to get the most out of SMF records. With respect to the different record structure, each SMF record type should have a chapter of its own with a table of formulas and a principal REXX example. The table should contain formulas together with all used SMF record fields and a description of the derived values.