Device containing system roots:

    Configuring cluster satellites involves finding the system root from
    which the satellite boots.  Normally, this is SYS$SYSDEVICE:,
    although it is possible to install system roots to a different
    volume.

    The device given in response to this question will be searched for
    all system roots.  Those that are found which do not contain a
    checksum database are assumed to be Phase IV nodes, and are
    candidates for being flagged for Phase V autoconfiguration.