Cisco UCS FI 6296 Unresponsive after reboot

This is a late post for an issue I came across with our Cisco UCS 6296 Fabric Interconnects. It may come handy to someone.

Issue: The FI 6296 will become unresponsive after a reboot. In my case, it was after a firmware upgrade. The error in our case was that the system was incorrectly detecting that the fans were spinning in the opposite direction and as a precautionary measure, FI was shutting itself down. This also affects Nexus 5596.

The issue is detailed in the Cisco Field Notice FN – 64094 – Nexus 5596/UCS FI 6296 – System Failed to Boot after a Power Cycle, Microcode Upgrade Required

Or use the Cisco Bug Search Tool for CSCun00720

The issue exists on FI’s that have the microcode 1.0. To resolve this issue, the microcode needs to be upgrade to 1.1.

To check the microcode version in your FI, perform the following

  • SSH into one of the FI’s (I use putty)
  • Type in connect nxos. This will take you into the NX OS configuration
  • Type show sprom sup | inc H/W
  • If the H/W Version is 1.0, then you are affected by the bug. Contact Cisco TAC to upgrade the microcode to 1.1

Hope this is helpful to someone.