VMS Help MOUNT, Qualifiers, /WINDOWS  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /WINDOWS=n

    Specifies the number of mapping pointers to be allocated for file
    windows.

    The parameter, n, specifies a value from 7 to 80 that overrides
    the default value specified when the volume was initialized.

    When a file is opened, the file system uses the mapping pointers
    to access data in the file. Use MOUNT/WINDOWS to override the
    default value specified when the volume was initialized. If no
    value was specified at volume initialization, the default number
    of mapping pointers is 7.

    You must have the operator user privilege (OPER) to use the
    /WINDOWS qualifier.

    Example

    The following command makes the volume labeled GONWITH on DKA2
    available systemwide and assigns the logical name THE_WINDOW. You
    override the default number of mapping pointers by specifying a
    value of 25 for the /WINDOWS qualifier.

    $ MOUNT/SYSTEM/WINDOWS=25 DKA2: GONWITH THE_WINDOW