Structure of the Trace File

The Trace file is used for the following primary purposes:

• to track updates of the Media Database

  This information is used to facilitate recovery of the Media Database when necessary.

• to serve as a queue for requests to be performed by the IOA Functional monitor

The Trace file is automatically maintained by Control‑M/Tape mechanisms that handle the Media Database and the requests to the IOA Functional monitor.

The length of logical records in the Trace file can vary, depending on the type of information in the record.

Logical records in the Trace file are composed of a header (mapped by macro CTTARC) followed by the record data (mapped by the macro relevant for the type of traced action).

The Trace file is processed as a cyclic file. When the file is full new records overwrite the oldest logical records. When the physical end‑of‑file is reached, the next record is written on the first physical record.

Note: The Trace file is not a database and it therefore is not managed as an IOA Access Method database.

Fields in the Trace File

The following table lists some of the more important fields in the Trace file. For a comprehensive list of these fields, see Logical Field Names for the Control-M/Tape Repository and the IOA MAC library.

Table 231 Fields in the Trace File

Note: The Trace file can be copied to a sequential variable-blocked file, enabling the output to be formatted in a number of different ways. (For more information, see the description of the CTTACP utility in the INCONTROL for z/OS Utilities Guide.)