In this video, I will tell you how to manage the GRUB2 configuration.
So GRUB2 is used to load the kernel and the initial RAM file system, init-ramfs if you're
on Red Hat, init-rd if you are on Ubuntu.
GRUB2 works with an input file, which normally is an etc-default GRUB.
All configuration settings are stored in the etc-grub.d configuration.
Now from the input file, you can use the grub2-mkconfig-o boot-grub2-grub.cfg file.
And that is combining the changes in the input file to the configuration file.
Let's check it out.
So etc-default has the file grub, and this is where it all starts.
And here you can find the line grub-cmd-line-linux with all the different options.
But there is also this grub-enable-bls-cfg is true.
And this option makes it you don't write it here anymore, but you need to write it somewhere
else.
Let me show you.
If you go to the boot directory, in the boot directory, you will find everything that is
needed for booting, including the grub2 configuration directory and the loader directory.
And in this loader directory, you have the entries, and the entries correspond to all
the different entries in your grub boot menu.
Now the thing is that before you would edit the etc-default grub file, but that was generic.
What are you going to do in a configuration with multiple boot entries where you want
to specify one specific entry?
That is what this bls-cfg option that we have just seen is all about.
So what you edit is in boot loader entries, and the entry, well, you need to find what
corresponds to your current configuration.
And in my case, that is the dash 6.6 and so on.
This is the one.
So if I want to change anything, like I want to remove this rh-zb and quiet, I go to the
options line, and at the end of the options line, I'm removing my rh-zb and quiet.
This is important to realize, because before it was more straightforward.
You would just remove the options from the grub-cmd-line Linux, but now that we have
grub-enable-bls-cfg, that doesn't work anymore.
What still works is grub2-mkconfig-o boot-grub2-grub.cfg.
That's going to write the options and make sure that your changes are saved persistently.
So when I'm going to reboot, I should see the difference.
It always starts with a few seconds of cursor in the upper left corner.
This is the difference.
I now no longer see this graphical screen hiding my boot messages.
I actually see what is going on on my system.