Record Type 41 (29) — DIV Objects and VLF Statistics

Reference information

COFVLFxx parmlib member is described in z/OS MVS Initialization and Tuning Reference.

Record type 41 provides resource usage information regarding data-in-virtual (DIV) objects and VLF statistics. This record is written when a DIV object is accessed, and when the object is unaccessed.

Note: ACCESS and UNACCESS is similar to OPEN and CLOSE. This record is also written to record VLF statistics.

Record type 41 has the following subtypes; each contains a common section with header and product information portions, and a subtype section unique for each record. The subtypes are:

Subtype 1 — ACCESS record. The ACCESS data section is written when a DIV object is accessed.
Subtype 2 — UNACCESS record. The counts for the I/O Activity Section are accumulated by data-in-virtual while the object is in use and are reported at the time of the UNACCESS request. The subtype 2 record is written whenever a data-in-virtual object is unaccessed.
Subtype 3 — collects virtual lookaside facility (VLF) statistics. It is written every 15 minutes. The data is repeated for each VLF class defined in the COFVLFxx parmlib member.