Use VTVIT to determine which VIT options were in effect at the time of a dump, and whether the trace was running internally (MODE=INT), externally (MODE=EXT), or internally and externally.

If the VIT was running externally, no further processing occurs. IPCS symbols are created for the beginning and end of the internal VIT table, and for the current, oldest, and last VIT entries.

An option is available to produce an unformatted listing of the entire VIT table. Use VTBASIC to format the VIT table.

To extract a VIT from a dump for use with the VIT analysis tool, use VITAL.

Operands

Search argument

Scan displays the VIT entries containing a specified search argument. Enter 1–8 alphanumeric characters or 1–16 hexadecimal digits in the form X'x…' for the search argument.

If the hexadecimal data string is not an even number of digits, the high-order half-byte is set to 0.

List VIT

The default is N. Specify Y to list the entire VIT table. The internal VIT table is processed in the following order:

1. From the oldest trace entry in the trace table in 64-bit common (HVCOMMON) storage to the end of the trace table.
2. From the beginning of the trace table in 64-bit common (HVCOMMON) storage to the current entry.

This results in "unwrapping" the trace table so the trace entries are processed and listed in chronological order (that is, the oldest trace entry is listed first at the top of the output, and the newest trace entry is listed last at the bottom of the output). A message is included in the output to indicate where the physical end of the trace table was encountered.

Equated symbol

Symbol

Description

VIT

The beginning of the VIT table

VITC

The current VIT entry

VITO

The oldest VIT entry

VITE

The end of the VIT table.

Use the following syntax as an alternative to the panel interface.

Additional information

The beginning of the trace table is mapped by ITTRC in z/OS Communications Server: SNA Data Areas Volume 1. It contains the present-wrap time stamp, last-wrap time stamp, current-entry address, and last-entry address. The current entry is the most recent entry (that is, the last entry to be written before the dump was taken). The last entry is the one that was written in the last position of the in-storage trace table before wrapping to the beginning of the trace table.