Normally, the correct volume is already mounted on the tape device if the VOLUME operand of the FILE macro or the VOLUME operand of the CREATE-FILE, IMPORT-FILE or CREATE-TAPE-SET command was specified correctly.
However, in exceptional cases, the operator may have mounted the “wrong” tape. The message “RETRY WITH ANOTHER VOLUME” is then issued during label checking.
The user can now retry label processing in interactive mode. If the error recurs, the user is requested to enter a new VSN so that a different tape is mounted. In the case of output and foreign files, the catalog entry is updated with this new VSN as soon as the mount operation has been completed.
Before the operator answers the error message on the console for continued tape processing, he/she can change the tape in the event of an error. The VSN of the new tape is normally identical with the VSN in the catalog entry.
If the VSN of the new tape differs from that in the catalog entry, the catalog entry is updated. This happens in the following cases:
the file was created (OPEN OUTPUT/OUTIN) with or without specification of a TSET, and is being used for the first time or after tapes have been changed
the file is being imported (STATE=FOREIGN or IMPORT-FILE command)
the file is being extended onto a new tape since the existing tapes are full.
In these cases, an “acknowledge VSN” is issued at the console as soon as the operator has answered the “RETRY” message.