/sys$common/syshlp/helplib.hlb Sys Parameters, SHADOW_MAX_COPY  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Use this parameter for Phase II shadowing only. The value of
    SHADOW_MAX_COPY controls how many parallel copy threads are
    allowed on a given node.

    Carefully consider the needs of each shadowed VAX node when you
    set this parameter. Too high a value for SHADOW_MAX_COPY can
    affect performance by allowing too many copy threads to operate
    in parallel. Too low a value unnecessarily restricts the number
    of threads your system can effectively handle.

    See Volume Shadowing for OpenVMS for more information about
    setting system parameters for volume shadowing.

    SHADOW_MAX_COPY has the AUTOGEN and DYNAMIC attributes.