/MV_INTVL=n

    Overrides the system-wide setting of the MVSUPMSG_INTVL system
    parameter with the value specified by n (seconds) for the
    specified device only. If /MV_INTVL=0, the value for MVSUPMSG_
    INTVL is used instead. If MVSUPMSG_INTVL=0 or MVSUPMSG_NUM=0,
    all mount verifications are announced. For more information about
    MVSUPMSG_INTVL, see Sys_Parameters online help.