MPDEV_AFB_INTVL specifies the automatic failback interval in
    seconds. The automatic failback interval is the minimum number
    of seconds that must elapse before the system attempts another
    failback from an MSCP path to a direct path on the same device.

    MPDEV_POLLER must be set to ON to enable automatic failback. You
    can disable automatic failback without disabling the poller by
    setting MPDEV_AFB_INTVL to 0. The default is 300 seconds.