VMS Help Sys Parameters, RMS_DFMBFSUR  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    RMS_DFMBFSUR establishes the default multibuffer count for unit
    record devices.

    You can set this system parameter with the DCL command
    SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
    DEFAULT.

    RMS_DFMBFSUR is an AUTOGEN and DYNAMIC parameter.