NL/BLP

For NL/BLP requests, the operator can be prompted to confirm that the mounted volume is the volume requested by the user (by JCL, dynamic allocation, and so on). Installation parameters determine whether or not confirmation is required. Nonspecific (SCRATCH) tape requests always result in a prompt.

After mounting a scratch NL tape in response to a user request for a nonspecific NL/BLP tape, the operator is prompted by Control-M/Tape twice (or more, if necessary) to confirm the volser of the mounted volume. Control-M/Tape does not accept the mounted tape until the operator replies two consecutive times with the same volser. Once the operator replies two consecutive times with the same volser, that volser is used by Control-M/Tape for processing Media Database access and by the operating system for cataloging, keep message, and so on.

After mounting a tape in response to a user request for a specific NL/BLP tape, the operator is prompted by Control-M/Tape to confirm the volser of the mounted volume.

If the operator replies with the same volser that was requested by the user, Control-M/Tape accepts the request and processing continues.

If, however, the operator replies with a volser that is different from the volser requested by the user, Control-M/Tape keeps prompting the operator for the volser of the volume mounted until the operator provides two consecutive identical replies. Once two identical, consecutive replies have been received, Control-M/Tape proceeds as follows:

• If the volser specified in the reply is identical to the volser requested by the user, processing continues.
• If the volser specified in the reply is different from the volser requested by the user, the current volume is rejected (by normal MVS reject). The mount request is issued again and this entire process repeats.

The message ID of the mount message (IEF233 or IEC501) is changed by Control-M/Tape to CTT100A. If a pool name is inserted in the message the message ID is changed to CTT101A. For more information, see "Scratch Processing" in this chapter.

Because Control-M/Tape is responsible for data integrity, the operating system expiration protection message IEC507D, "E ... REPLY ‘U’-USE OR ‘M’-UNLOAD," is usually suppressed. This message is not suppressed when:

• Control-M/Tape is operating in Global Test or Phased mode.
• A rule specifies that the current data set is managed in Test mode.
• The volume is not controlled by Control-M/Tape (meaning, the volume is not registered in the Media Database, even if the volume is to be defined dynamically to Control-M/Tape).

If the volume is marked as in a remote vault, this indication is corrected at this time, and the tape is returned from borrowed status.