Standard SMF record header

Each record written to the SMF data set by the SMF writer routine contains the standard SMF record header. Each user record written to the SMF data set, by user-written routines, should include the standard record header. The length and field types for the record header vary with the kind of record writer. Table 1 shows the header for records without subtypes; its length is 18 bytes. Table 2 shows the header for records with subtypes; its length is 24 bytes.

The header contains information about the record, such as; record type, record subtype (if the record includes subtypes), record length, and the time and date the record was written to the data set. The time in the header record is based on the LOCAL TIME. Record subtypes are used to group related data and control record types. For example, one record might contain three separate subtypes, each reporting different kinds of data. By using those subtypes you can eliminate the need for three separate record numbers.

The header section must include the record descriptor word (RDW). The RDW is a 4-byte field that must introduce each SMF record when it is written to the SMF data set by the SMFWTM macro instruction. The first two bytes of the RDW must contain the length of the logical record (including the four bytes of the RDW). The second two bytes are used for variable blocked spanned records; that is, records that contain more than 32,756 bytes. This field (the second two bytes) is set to zero if the record is not spanned. The remainder of the record immediately follows the RDW.

Because the record formats include the RDW, it is not necessary to add four bytes to the offset listed in the record; however, depending on the access method used to read the record from the SMF data set, these fields might not be present in your SMF record. You might have to subtract four bytes from the offsets listed in your record.

Table 1. Standard SMF Record Header for Records without Subtypes
Offsets	Name	Length	Format	Description
00	00	SMF`x`LEN	2	binary	Record length (maximum size of 32,756). This field and the next field (total of four bytes) form the record descriptor word (RDW). The first two bytes (this field) must contain the logical record length including the RDW.
02	02	SMF`x`SEG	2	binary	Segment descriptor provide by SMF. Initialize with zeros.
04	04	SMF`x`FLG	1	binary	System indicator: Bit Meaning when set 0-2 Reserved 3 MVS/SP Version 4 and above. Bits 3, 4, 5, and 6 are on.* 4 MVS/SP Version 3. Bits 4, 5, and 6 are on. 5 MVS/SP Version 2. Bits 5 and 6 are on. 6 VS2. Bit 6 is on. 7 Reserved. * IBM® recommends that you use information located elsewhere in this record to determine the MVS™ product level.
05	05	SMF`x`RTY	1	binary	Record type (hexadecimal values are 0-FF).
06	06	SMF`x`TME	4	binary	Time since midnight, in hundredths of a second, record was moved into the SMF buffer. In record types 2 and 3 this field indicates the time that the record was moved to the dump data set.
10	0A	SMF`x`DTE	4	packed	Date when the record was moved into the SMF buffer, in the form 0`cyydddF` (where `c` is 0 for 19xx and 1 for 20xx, `yy` is the current year (0-99), `ddd` is the current day (1-366), and `F` is the sign). In record types 2 and 3, this field indicates the date that the record was moved into the dump data set.
14	0E	SMF`x`SID	4	EBCDIC	System identification (from the SID parameter).

Table 2. Standard SMF Record Header for Records with Subtypes
Offsets	Name	Length	Format	Description
00	00	SMF`x`LEN	2	binary	Record length (maximum size of 32,756). This field and the next field (total of four bytes) form the record descriptor word (RDW). The first two bytes (this field) must contain the logical record length including the RDW.
02	02	SMF`x`SEG	2	binary	Segment descriptor provided by SMF. Initialize with zeros.
04	04	SMF`x`FLG	1	binary	System indicator Bit Meaning when set 0 Reserved. 1 Subtypes are valid. 2 Reserved. 3 MVS/SP Version 4 and above. Bits 3, 4, 5, and 6 are on. (IBM recommends that you use record type 30 to obtain the MVS product level.) 4 MVS/SP Version 3. Bits 4, 5, and 6 are on. 5 MVS/SP Version 2. Bits 5 and 6 are on. 6 VS2. Bit 6 is on. 7 Reserved.
05	05	SMF`x`RTY	1	binary	Record type (hexadecimal values are 0-FF).
06	06	SMF`x`TME	4	binary	Time since midnight, in hundredths of a second, that the record was moved into the SMF buffer. In record types 2 and 3, this field indicates the time that the record was moved into the dump data set.
10	0A	SMF`x`DTE	4	packed	Date when the record was moved into the SMF buffer, in the form 00`yydddF` or 0`cyydddF` (where `c` is 0 for 19xx and 1 for 20xx, `yy` is the current year (0-99), `ddd` is the current day (1-366), and `F` is the sign). In record types 2 and 3, this field indicates the date that the record was moved to the dump data set.
14	E	SMF`x`SID	04	EBCDIC	System identification (from the SID parameter).
18	12	SMF`x`SSI	4	EBCDIC	Subsystem identification. This field is a four byte character value set by the SUBSYS=option specified in the SMF macros.
22	16	SMF`x`STY	2	binary	Record subtype (hexadecimal values are 0-FF). See SYS and SUBSYS with TYPE and NOTYPE — Selecting subtypes for SMF recording for a description of subtype selectivity.