Volumes = n

    Allows you to specify that concurrent tape access is to be used
    to accelerate the restore operation.

    The Volumes qualifier indicates concurrent tape access and
    specifies the number of tape volumes in the backup file. The
    number of volumes must be specified accurately for the restore
    operation to complete.

    If you are restoring from a multidisk backup file, the value of
    "n" indicates the number of disk devices containing backup files
    needed for the restore operation.

    If you do not specify the Volumes qualifier, the restore
    operation does not use concurrent tape access.