/sys$common/syshlp/helplib.hlb SET, DEVICE, Qualifiers, /ENABLE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /ENABLE
       /NOENABLE

    Enables or disables a path to a multipath device; the affected
    path is the one named in the /PATH qualifier. All paths are
    initially enabled; the current path cannot be disabled.