Activating the VIT

You must activate the VIT to record the trace data of the specific events.

You do not need to activate the trace data of the following events, because the data is always automatically recorded in the internal table:
  • API
  • CIO
  • MSG
  • NRM
  • PIU
  • PSS (You can deactivate this internal trace option to stop automatic recording)
  • SMS (You can deactivate this internal trace option to stop automatic recording)
  • SSCP

To activate the internal trace, do one of the following actions:

If you want to use VIT to record 32, 64, 96, or 128 bytes of user-generated information in an SNAP trace, see Recording SNAP traces.

Note:
  1. To prevent the VIT table from being overwritten, VTAM disables the internal VIT when it issues SDUMP and when an FFST™ probe is tripped.
  2. The minimum trace table size is 4 megabytes. Because the eight trace option default values are always running, the table might wrap many times.
  3. CIDCTL FIND macro invocations that are invoked during the process of sending or receiving data are not traced with CDHF or CDNF trace entries unless they result in a nonzero return code.
Parent topic: Using the VTAM internal trace