Monitoring the CPU module

LEDs on the CPU module

The CPU module has several LEDs. The LEDs indicate whether the CPU module, Fibre Channel ports, and network connections are functioning normally.

The following illustration shows the location of the Fibre Channel LEDs at the rear of the CPU module.

Use the following table to interpret the Ethernet port LEDs on the CPU module.

Link LED (green)	Activity LED (amber)	State
Off	Off	Network connection is not present.
On	Off	Network connection is present but there is no data input or output occurring.
On	On/blinking	Network connection is present and data input and output is occurring.

Use the following table to interpret the Fibre Channel LEDs on the CPU module.

Fault LED (amber)	Fibre Channel B LED (green)	Fibre Channel C LED (green)	State	Action
Off	On	On	Normal	None.
Off	Off	On	Loop B fault	Fibre Channel B loop is open and needs to be fixed.
Off	On	Off	Loop C fault	Fibre Channel C loop is open and needs to be fixed.
On	On	On	CPU module fault	Perform the following steps until the problem is resolved: Check the cables at the rear of the appliance. Make sure that the 1 Gb/ 2 Gb switches are set to 1 Gb. Check all terminate switches. Last shelf in the loop must be set to On. All other shelves must be set to Off. If Fibre Channel C port is unused, install the Fibre Channel terminator or ignore the Fibre Channel C LED. It is alright for the LED to be off if the port is not used. Run diagnostics to isolate the failure and decide whether CPU module replacement is necessary. See the Diagnostics Guide for more information. Replace the CPU module. See Replacing the CPU module. Contact Network Appliance Customer Service.
On	Off	On	Loop B fault and module fault
On	On	Off	Loop C fault and module fault