UCS 4.x UEFI update

In the scenario where I have UCS 4.x with UEFI installed, what is the correct way to update to the UCS 5.x version?


I have a server with UEFI configured, and UCS 4.x
The purpose is to update to UCS 5.x version
Should I be concerned about the UEFI issue? I can “Change the Boot Mode (UEFI/Legacy)?”


Leave UEFI. There is no reason to change to an older (legacy) mode.

In the documentation, this issue is mentioned, what is it about? Will I have a problem migrating UCS 4.x with UEFI to UCS 5.x?

Simultaneous operation of UCS and Debian on UEFI systems
Please note that simultaneous operation of UCS and Debian GNU/Linux on a UEFI system starting with UCS 5.0 isn’t supported.

The reason for this is the GRUB boot loader of Univention Corporate Server, which partly uses the same configuration files as Debian. An already installed Debian leads to the fact that UCS can’t boot (anymore) after the installation of or an update to UCS 5.0. A subsequent installation of Debian results in UCS 5.0 not being able to boot. For more information, refer to KB 17768.

I understand the issue description in a case of a dual boot configuration of UCS and an alternative Debian. The issue seens not to be present on single boot systems.

A couple of months ago I upgraded my UCS 4 to 5 without any problems on my UEFI configured VM.

I understand, thank you for your help
in fact, I only have a single installation.
I’ll continue with the update and see how it behaves.