Extracting VIT information from a dump

Use one of the following methods to analyze dumps.

• Use the dump analysis tools for the VIT:

  VITAL

  Extracts an internal VIT from a dump for use with the VIT analysis tool.

  VTBASIC

  Displays the VIT table.

  VTVIT

  Displays the VIT options that were in effect at the time of the dump and whether the trace was running internally, externally, or both.

  See "Using VTAM® dump analysis tools" in z/OS Communications Server: SNA Diagnosis Vol 1, Techniques and Procedures for more information about the VTAM dump analysis tools.

• Use this procedure:
  1. Examine the internal trace table by taking a dump of VTAM with the appropriate storage area.
  2. Find the internal trace table in the dump by first locating the ATCVT.
     • If low-storage location X'408' is available in the dump, the pointer to the ATCVT (ATCLCPTR) is at this low-storage location.
     • If low-storage location X'408' is not available in the dump, use the pointer in the MVS™ CVT control block extension (CVTATCVT) to find the VTAM control block AVT. Location hex 00 in the AVT points to the ATCVT.
  3. In the ATCVT, field ATCITTBL contains a 64-bit pointer to the trace table. ATCITTBL is located at offset X'8'. The internal trace table contains a 64-byte header followed by 32-byte trace records.