VMS Help Sys Parameters, MC_SERVICES_P2  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    (Alpha only) MC_SERVICES_P2 specifies whether to load the
    PMDRIVER (PMA0) MEMORY CHANNEL cluster port driver.

    PMDRIVER is a new driver that serves as the MEMORY CHANNEL
    cluster port driver. It works together with MCDRIVER (the
    MEMORY CHANNEL device driver and driver interface) to provide
    MEMORY CHANNEL clustering. If PMDRIVER is not loaded, cluster
    connections are not made over the MEMORY CHANNEL interconnect.

    The default value is 1, which causes PMDRIVER to be loaded when
    you boot the system. When you run CLUSTER_CONFIG.COM and select
    the MEMORY CHANNEL option, PMDRIVER is loaded automatically when
    you reboot the system.

    Compaq recommends that this value not be changed. This parameter
    value must be the same on all nodes connected by MEMORY CHANNEL.