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....