For Control-M/Tape to instruct the operating system to fast position a tape to a data set, all of the following conditions must be met:
A rule is defined with an appropriate DO FASTPOS statement.
The tape device supports Fast Positioning. Tape devices 3480, 3490, 3490E, and 3590 all support Fast Positioning.
The tape is a standard label tape.
Either:
You are reading or rewriting a data set whose position Control-M/Tape has stored in the Media Database, or
You are adding a data set to a tape, and Control-M/Tape has stored the position of the logical end of tape in the Media Database.
If you are rewriting a data set, you are not appending to the data set (that is, the JCL does not include the expression DISP=MOD, and the program does not open the data set with an option that implies that expression).
