Any issue when Infrastructure firmware lower than server firmware?

[Markus5849]

Will there be any issue if I'm about to connect my C-series server to my FI cluster with lower firmware version? My C-series server is with 4.2(2a) and my FI is 4.1(3c). In this case capability catalog will not working I guess since the version gap is too huge between 4.1 and 4.2.

Appreciate anyone could assist to answer this and guide me through the proper steps for adding in server with later firmware version to FI cluster. And I would like to know as well if there's anyways for me to downgrade my server firmware without using FI? Because there are too many servers and hyperflex clusters inside the UCS cluster so upgrading all of them to 4.2(x) will be time consuming. 

[Wes Austin]

The release notes outline supported Infra/Server firmware combinations. You cannot have server at 4.2 and UCSM at 4.1.

https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/release/notes/CiscoUCSManager-RN-4-1.html 

Why not downgrade the server firmware using the FI? You should be able to downgrade the BIOS and then CIMC from 4.2 to 4.1 and then discovery your C-series server using the installed firmware tab, assuming your rack server is discovering far enough to detect the versions. Otherwise, you would need to use the HUU to deploy the server in standalone mode and downgrade the CIMC/BIOS that way. Make sure if you use this method you reset the CIMC to factory defaults before attempting to re-integrate into UCSM.

https://www.cisco.com/c/en/us/td/docs/unified_computing/ucs/c/sw/lomug/2-0-x/3_0/b_huu_3_0_1/b_huu_2_0_13_chapter_011.html 

[Markus5849]

You mean that I can just plug in the server to my FI (4.1 firmware) and then from there just downgrade the server firmware? In this case the firmware Auto Install will not work and have to downgrade each component separately?

[Wes Austin]

Yes you can do this. You just need to downgrade the BIOS first, then CIMC. Once this is complete you can apply your service profile to upgrade/downgrade all the other components on the server. 

Would not use Auto-Install to conduct this, its pretty straight forward to do it manually. 

[Markus5849]

I see, would you mind to assist on verifying if below steps are correct to downgrade the firmware if the node is going to build a new hyperflex cluster.

• Connect server 4.2 to FI 4.1
• Configure server port for the server
• Downgrade the BIOS and CIMC manually
• Run HXDP installer and choose firmware version 4.1 to downgrade all other components during cluster installation 

[Wes Austin]

Once the server is discovered and service profile is applied, the host firmware package will automatically upgrade/downgrade any components to the version that is outlined. 

[Markus5849]

Hi Austin,

Im a bit confused that if I connect the server to my FI and configure server port, will there be any issue? To downgrade the BIOS and CIMC I still have to connect the server and configure server port right?

Because I'm curious that if I can't discover the server how should I downgrade the server using my FI?

[Wes Austin]

There should not be any issues. Think of it like you just recieved a replacement server and the replacement server came with higher firmware than what is already running on UCSM. You would downgrade the server firmware after enabling server ports and getting server to be seen in UCSM. It may not discover fully, but should be enough for you to downgrade CIMC/BIOS. 

If this process does not work or you are not comfortable with it, you can follow the steps to downgrade the server in standalone mode.

[Markus5849]

Alright, I'll try with the downgrade approaches and revert the result to you. Thanks for your useful information Austin.