On Nov 16, 2023, at 03:02, Jeffrey Walton <noloader(a)gmail.com> wrote:
On Wed, Nov 15, 2023 at 11:33 AM fedoraUser 2023 <fedorauser86(a)gmail.com> wrote:
>
> Fedora/CentOS/RHEL boot only from this grub. When install Fedora and CentOS, CentOS
no boot from Fedora boot loader, Fedora no boot From CentOS boot loader. Why?
Have you updated GRUB recently?
As I understand things, GRUB is not updated automatically. Once
installed, it has to be updated manually. In fact, it is an option
upgrade step at
<
https://docs.fedoraproject.org/en-US/quick-docs/upgrading-fedora-offline/...;.
Nope, you don’t need to touch the grub configuration once installed on a Fedora system
unless you have changed the settings in /etc/sysconfig/grub or you’ve updated to a new
Fedora release (and that’s done automatically, I believe).
New kernels drop a file in /boot/loader/entries/ as part of the post-install script, and
those files are read by grub during boot.
Now there have been people who post to this list that have managed to mess up their system
to the point where they have to manually run grub2-mkconfig after each kernel update, but
that’s not the default behavior of Fedora.
And there's the forbidden signature database that blacklists
buggy
versions of GRUB...
<
https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/...;.
This is something you’d get as a firmware update, either through fwupd, a windows update
(dual-boot) or by manually updating the BIOS/firmware though some out-of-bound method. DBX
updates change the firmware and not grub2.
--
Jonathan Billings