Maintaining the T640 Fan Trays

Purpose

For optimum cooling, verify the condition of the fans.

Action

On a regular basis:

• Monitor the status of the fans. The fan trays each contain multiple fans that work in unison to cool the router components. If one fan fails, the host subsystem adjusts the speed of the remaining fans to maintain proper cooling. A red alarm is triggered when a fan fails, and a yellow alarm is triggered when a fan tray is removed.
• To display the status of the fans, issue the show chassis environment command or show chassis fan command.

  For the standard front fan trays and standard rear fan tray with eight fans, the output for the show chassis environment command is similar to the following:

  user@host> show chassis environment

  Class Item                    Status  Measurement
  ...
  Fans  Top Left Front fan             OK         Spinning at normal speed
        Top Left Middle fan            OK         Spinning at normal speed
        Top Left Rear fan              OK         Spinning at normal speed
        Top Right Front fan            OK         Spinning at normal speed
        Top Right Middle fan           OK         Spinning at normal speed
        Top Right Rear fan             OK         Spinning at normal speed
        Bottom Left Front fan          OK         Spinning at normal speed
        Bottom Left Middle fan         OK         Spinning at normal speed
        Bottom Left Rear fan           OK         Spinning at normal speed
        Bottom Right Front fan         OK         Spinning at normal speed
        Bottom Right Middle fan        OK         Spinning at normal speed
        Bottom Right Rear fan          OK         Spinning at normal speed
        Rear Tray Top fan              OK         Spinning at normal speed
        Rear Tray Second fan           OK         Spinning at normal speed
        Rear Tray Third fan            OK         Spinning at normal speed
        Rear Tray Fourth fan           OK         Spinning at normal speed
        Rear Tray Fifth fan            OK         Spinning at normal speed
        Rear Tray Sixth fan            OK         Spinning at normal speed
        Rear Tray Seventh fan          OK         Spinning at normal speed
        Rear Tray Bottom fan           OK         Spinning at normal speed...

  Top Left and Top Right refer to fans in the upper front fan tray. Bottom Left and Bottom Right refer to fans in the lower front fan tray. Rear refers to the fans in the rear fan tray.

  For the quiet fan trays, the output for the show chassis environment command is similar to the following:

  user@host> show chassis environment

  Class Item                    Status  Measurement
  Fans  Top Left Front fan             OK         Spinning at normal speed
        Top Left Rear fan              OK         Spinning at normal speed
        Top Right Front fan            OK         Spinning at normal speed
        Top Right Rear fan             OK         Spinning at normal speed
        Bottom Left Front fan          OK         Spinning at normal speed
        Bottom Left Rear fan           OK         Spinning at normal speed
        Bottom Right Front fan         OK         Spinning at normal speed
        Bottom Right Rear fan          OK         Spinning at normal speed
        Rear Tray Top fan              OK         Spinning at normal speed
        Rear Tray Second fan           OK         Spinning at normal speed
        Rear Tray Third fan            OK         Spinning at normal speed
        Rear Tray Fourth fan           OK         Spinning at normal speed
        Rear Tray Fifth fan            OK         Spinning at normal speed
        Rear Tray Sixth fan            OK         Spinning at normal speed
        Rear Tray Seventh fan          OK         Spinning at normal speed
        Rear Tray Bottom fan           OK         Spinning at normal speed

  Top Left and Top Right refer to the four fans in the upper front fan tray. Bottom Left and Bottom Right refer to the four fans in the lower front fan tray. Rear refers to the eight fans in the rear fan tray.

  For the standard front fan trays and standard rear fan tray with eight fans, the output for the show chassis fan command is similar to the following:

  user@host> show chassis fan

        Item                      Status   RPM     Measurement
        Top Left Front fan        OK       3420    Spinning at normal speed
        Top Left Middle fan       OK       3420    Spinning at normal speed
        Top Left Rear fan         OK       3450    Spinning at normal speed
        Top Right Front fan       OK       3420    Spinning at normal speed
        Top Right Middle fan      OK       3420    Spinning at normal speed
        Top Right Rear fan        OK       3420    Spinning at normal speed
        Bottom Left Front fan     OK       3420    Spinning at normal speed
        Bottom Left Middle fan    OK       3450    Spinning at normal speed
        Bottom Left Rear fan      OK       3360    Spinning at normal speed
        Bottom Right Front fan    OK       3420    Spinning at normal speed
        Bottom Right Middle fan   OK       3420    Spinning at normal speed
        Bottom Right Rear fan     OK       3420    Spinning at normal speed
        Rear Tray Top fan         OK       5190    Spinning at normal speed
        Rear Tray Second fan      OK       5190    Spinning at normal speed
        Rear Tray Third fan       OK       5190    Spinning at normal speed
        Rear Tray Fourth fan      OK       5190    Spinning at normal speed
        Rear Tray Fifth fan       OK       5190    Spinning at normal speed
        Rear Tray Sixth fan       OK       5190    Spinning at normal speed
        Rear Tray Seventh fan     OK       5190    Spinning at normal speed
        Rear Tray Bottom fan      OK       5190    Spinning at normal speed
  

  For the quiet fan trays, the output for the show chassis fan command is similar to the following:

  user@host> show chassis fan

        Item                      Status   RPM     Measurement
        Top Left Front fan        OK       2220    Spinning at normal speed
        Top Left Rear fan         OK       2190    Spinning at normal speed
        Top Right Front fan       OK       2220    Spinning at normal speed
        Top Right Rear fan        OK       2250    Spinning at normal speed
        Bottom Left Front fan     OK       2220    Spinning at normal speed
        Bottom Left Rear fan      OK       2220    Spinning at normal speed
        Bottom Right Front fan    OK       2250    Spinning at normal speed
        Bottom Right Rear fan     OK       2220    Spinning at normal speed
        Rear Tray Top fan         OK       5190    Spinning at normal speed
        Rear Tray Second fan      OK       5190    Spinning at normal speed
        Rear Tray Third fan       OK       5190    Spinning at normal speed
        Rear Tray Fourth fan      OK       5190    Spinning at normal speed
        Rear Tray Fifth fan       OK       5190    Spinning at normal speed
        Rear Tray Sixth fan       OK       5190    Spinning at normal speed
        Rear Tray Seventh fan     OK       5190    Spinning at normal speed
        Rear Tray Bottom fan      OK       5190    Spinning at normal speed