How to upgrade Cisco’s UCS CIMC firmware

The Cisco Integrated Management Controller is the out-of-band hardware controller included with the Cisco UCS servers and if you have read my previous blog post about the CIMC you already assigned it with an IP address, so today I’ll show you how to perform a firmware upgrade. I have a couple of UCS M220 M4 servers that shipped with a CIMC version 2.x and I decided to upgrade to 3.x due to key improvements, mainly an HTML 5 based vKVM instead of painful Java.

Note – This procedure dates from  mid-2018. At the time of this writing there’s a 4.x release for CIMC’s firmware, being 4.0(2c) the recommended release. This procedure is still valid to upgrade to 4.x unless explicitly noted by the firmware release notes. If you want to play safe first update to a 3.x release and then move up to 4.x.

1 Go to and download the CIMC firmware file you want to upgrade to. In my case, I’ll upgrade to 3.0.3(f). You will need a valid service contract associated with your CCO account before downloading the file. This .iso file is also referenced as HUU or Host Upgrade Utility.

2 Login to the CIMC’s web interface and launch the vKVM console at the  Server/Summary  tab. Be aware that having the incorrect Java version pose issues to launch the vKVM in versions 2.x, that’s why we’re upgrading.

3 On the vKVM window go to the  Virtual Media  tab and select  Activate Virtual Devices . It seems that nothing happened but if you go back to the same tab you will now see the option  Map CD/DVD . Click it, browse and select your firmware’s .iso image and finish by clicking  Map Device .

4 Go to  Power  and hit  Reset System (warm reboot) . The system will restart and you will be presented the initial UCS boot screen.  Hit F6  to enter the Boot Menu.

5 To enter the Boot Menu enter your CIMC admin password and from the menu select the vKVM mapped DVD unit to boot the upgrade utility.

6 The upgrade utility interface will show up and -unless you want to be very specific- hit  Update All . The process will take about 10 minutes and once finished it will display which components were updated and which were skipped (because the server already had the latest version). Hit  Exit  for the server to reload and finish the process.

7 To confirm the firmware upgraded successfully, log back to the CIMC and you should be presented with a new web interface, much modern and functional. If you hit Launch KVM you will see the new HTML 5 version, which is simply great. 

Sayonara root of all evil Java.

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