multipath returns error message: multipath.conf line XX, invalid keyword: XXXX

Issue

• Configured multipath for the Dell MD3660fc storage device and connected to 4 RHEL 5.9 servers but running multipath it returns this error:

multipath.conf line 25, invalid keyword: prio

• The multipath.conf file looks like this:

defaults {
        user_friendly_names yes
        max_fds max
        polling_interval        5
}

devices {
        device {
                vendor                  "3PARdata"
                product                 "VV"
                no_path_retry            12
                features                "0"
                hardware_handler        "0"
                path_grouping_policy    multibus
                path_selector           "round-robin 0"
                rr_weight               uniform
                rr_min_io               100
                path_checker            tur
                failback                immediate
        }

• After editing multipath.conf for new storage array, multipath retuns error message multipath.conf line XX, invalid keyword: XYZ. What need to be reviewed?