Replacing faulty PSU of the FEX switch

• FEX switches will be used to extend the I/O ports in the Data center.
• While managing the Nexus environment we will face some hardware failures in the Nexus switches and PSU failing is one of them.
• In most of the Nexus switches we will have redundancy power supply units and they can be hot swappable.

How to Identify the PSU status of FEX switches which are connected to parent switches?

• Login to the parent switch via SSH or console.
• Use below command to get the specific FEX PSU status.
• As per below output I am checking the PSU status of FEX 101.    

• As per above output we can see there should be some issue with 2nd PSU unit of the FEX.

Basic troubleshooting of PSU fail in the FEX:

• With the help of on-site team we should replace the existing power cable with another power cable(Working one).
• Make sure PDU is providing the enough power and after all checks if still PSU not detecting in the switch we will go for replacement of the PSU.

Providing the basic information to the RMA team who will replace the PSU:

• By using the below command we can provide the FEX serial number and model number to get the correct PSU which will support to the FEX switch.

• If RMA team need PSU model number also then use below command to get the information.

Replacing the Faulty PSU in FEX switch:

• Make sure you have proper approval for this activity.
• Ask on-site engineer to replace faulty PSU with working PSU without making any changes in the switch as PSUs are hot swappable.
• During the activity there should not be any interruption in switch operation as switch is already running with other PSU.
• Post faulty PSU replacement done by on-site engineer verify the PSU status with below command.

•  As per above output both the PSUs are working fine now in the FEX switch.

Thanks for your time in reading this post 

Sasidhar Chundu