Dell S4048-ON fantray missing


We got several Dell S4048-ON switches, on which we have a State Sensor Critical for fantray 4.
However, if I’m correct it only fits 3 fantray’s… So it shouldn’t say the 4th is missing as this isn’t even an option.

How would I correct this?

Hi @JimKlapwijk
You can have a look at the SNMP replies of the device (play with snmpwalk), and check if there is a way to find out that the Sensor of FanTray 4, which does not exist in that device, can be identified in it.

*************************** 4. row ***************************
                sensor_id: 860
           sensor_deleted: 0
             sensor_class: state
                device_id: 70
              poller_type: snmp
               sensor_oid: .
             sensor_index: 2.1.4
              sensor_type: dellNetFanTrayOperStatus
             sensor_descr: Fantray 4
                    group: Fans
           sensor_divisor: 1
        sensor_multiplier: 1
           sensor_current: 3
             sensor_limit: NULL
        sensor_limit_warn: NULL
         sensor_limit_low: NULL
    sensor_limit_low_warn: NULL
             sensor_alert: 1
            sensor_custom: No
         entPhysicalIndex: NULL
entPhysicalIndex_measured: NULL
               lastupdate: 2019-09-03 17:16:28
              sensor_prev: NULL
                user_func: NULL

That’s the above sensor ID…

So far, if LibreNMS discovers it, it means that :

  • Either LibreNMS does not catch the information “this fantray is not installed, you should not display it”
  • Or the device does not provide this information at all. Which means we cannot find out.

The idea is to search into the MIB file and the snmpwalk replies of the device if we are in the 1st situation, and how to identify a fantray that is not installed.