Mixed Port-Side Exhaust (PE) and Intake (PI) Fans/PSUs on Cisco C93180

[SRB-IT]

Hi everyone,

We recently received the correct replacement fans and power supplies for our Cisco C93180YC-FX3 switches. Previously, the wrong models (Port-Side Exhaust) were mistakenly delivered for our Nexus 9Ks.

Now, we’d like to install the correct Port-Side Intake (PI) fans and PSUs. Ideally, we want to perform this replacement while the switches remain operational. During the swap, there would briefly be a mix of both PE and PI fans/PSUs in the same device.

From a purely physical perspective, this mismatch shouldn’t cause issues. However, I’m aware that this configuration likely doesn’t align with Cisco's design guidelines, and a Nexus switch is more than just hardware. My key question is:

Will the switch tolerate this temporary mixed configuration, or could it trigger an emergency shutdown to prevent potential harm?

Thanks in advance for your advice!

[marce1000]

  - Difficult question for a unique answer , at least configure https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/6-x/system_management/configuration/guide/b_Cisco_Nexus_9000_Series_NX-OS_System_Management_Configuration_Guide/sm_5syslog.html#task_1077578

          to have console output on a connected SSH session before starting those operations.
          Watchout for errors , or critical messages.

          If the switch is business critical or supposed to be active 24/24 then consider scheduled maintenance
          to be safe in case if there is a failure.

   M.

[Pavel Tarakanov]

If you are changing the airflow direction of all the modules in the chassis, shutdown the switch before replacing all the fan and power supply modules with modules using the other airflow direction. During operations, all of the modules must have the same direction of airflow.

https://www.cisco.com/c/en/us/td/docs/dcn/hw/nx-os/nexus9000/93180yc-fx3/cisco-nexus-93180yc-fx3-nx-os-mode-switch-hardware-installation-guide/m_n93xxx_replacement.html