Hello,
we are running CentOS Stream 8 on some of our dedicated servers. On the newer servers that boot with efi, the system that is installed with the default properties in the ISO installer writes itself to the top of the efi boot order. This seems to happen every time after bootup.
Since we run all our systems with efi network boot as the first boot option for rescue operation, this would be a significant problem for the future if the behavior cannot be turned off.
I have already checked the use of efibootmgr and some of the related grub settings such as GRUB_DEFAULT and GRUB_SAVEDEFAULT (which may have nothing to do with it). On Debian, I found a debconf option that prevents updating nvram. This seems to prevent the described behavior.
Does anyone have an idea for this problem?
With kind regards Florian