(Alpha and Integrity servers) MPDEV_POLLER enables polling of
    the paths to multipath set members when set to ON (1).  Polling
    allows early detection of errors on inactive paths. If a path
    becomes unavailable or returns to service, the system manager is
    notified with an OPCOM message. When set to OFF (0),  multipath
    polling is disabled. The default is ON. Note that this parameter
    must be set to ON to use the automatic failback feature.