[CentOS] C8.1 Grub problem

Wed Apr 8 11:00:38 UTC 2020
Leon Fauster <leonfauster at googlemail.com>

Am 08.04.20 um 10:01 schrieb Alessandro Baggi:
> Il 08/04/20 01:46, Jonathan Billings ha scritto:
>> On Apr 7, 2020, at 04:14, Alessandro Baggi 
>> <alessandro.baggi at gmail.com> wrote:
>>> thank you for your explanation. So in el8 grubby should be used to 
>>> update kernel opts and grub2-mkconfig is used to generate an initial 
>>> config.
>>> If I'm not wrong, grubby updates every single (sperated) entries on 
>>> /boot/loader/entries and then generate the 
>>> /boot/efi/EFI/centos/grub.cfg?
>>> Suppose that I want use only grub2-mkconfig to generate the grub.cfg 
>>> what other operation are needed to make it working?
>> grubby only alters the existing configuration.  It never regenerates 
>> the grub.cfg in EFI.
>> You can’t use “grub2-mkconfig” to create individual boot spec entries.
>> -- 
>> Jonathan Billings <billings at negate.org>
> Please explain how the process work, it is not so clear for me. I'm 
> confused.
> In C7 when I need to modify grub menu kernel option I modify 
> /etc/default/grub and run grub2-mkconfig and thats all. It always worked 
> for me.
> On C8 this does not work anymore, grub2-mkconfig is not enough, it 
> generates only the grub.cfg but it does not update the menu entries and 
> need to modify each entry using grubby. At this point what grub.cfg is 
> used for if directives are not loaded by it and need grubby to modify 
> entries?
> I'm missing something....

Normally grub2-mkconfig is enough.

Whats your output of

# grub2-editenv list


# cat /proc/cmdline


# cat /etc/default/grub