(Alpha and Integrity servers) This parameter allows a system
    manager to define a site value, which Volume Shadowing uses to
    determine the best device to perform reads, thereby improving
    performance.

    The system manager can now define the site value to be used
    for all shadow sets mounted on a system. This parameter is an
    arbitrary numeric value coordinated by the system manager of
    disaster tolerant clusters. Reads from devices that have site
    values matching the shadow set's site value are preferred over
    reads from devices with different site values. For detailed
    information, see the description of the $SET DEVICE/SITE in the
    VSI OpenVMS DCL Dictionary and VSI Volume Shadowing for OpenVMS.

    SHADOW_SITE_ID is a DYNAMIC parameter.