Change Grub configuration and apply in Silverblue

[pauldoo (Paul Richards)]

Hello,
I would like to edit some of the Grub configuration on my install of Fedora Silverblue. If I go ahead and edit /etc/default/grub or add new files to /etc/grub.d/, what commands do I need to make that configuration active?

Since this is Silverblue I’m aware that grubby is not safe to use. I’m also aware that for kernel arguments specifically I can use rpm-ostree kargs. However, I’m interested in changing other bits of Grub configuration. (In case it matters I’m interested in trying different GRUB_TERMINAL settings as currently Grub menus render very very slowly.)

So, what is the recommended way to make changes to Grub configuration and apply it in Silverblue?

[sampsonf (Sampson Fung)]

Your linked post regarding grubby is very old.

I have been using grubby with Silverblue 33&34 to modify boot parameters without issues.

[bryanmoore]

Is this what you’re looking for?

grub2-mkconfig -o /etc/grub2.cfg
or
grub2-mkconfig -o /etc/grub2-efi.cfg

[pauldoo (Paul Richards)]

Maybe… ?

I know that Silverblue is a little bit different from regular Fedora in the way that booting is handled. I’m wary of using the normal Fedora docs, and was hoping to find some explicit confirmation that this approach is safe on Silverblue.

Maybe I should just try it.

[bryanmoore]

Hmm… I forgot about that; good point.

In reading through some of Silverblue’s documentation, it doesn’t seem like you’re trying to do anything too crazy, like dual boot.

This thread seems to suggest running rpm-ostree kargs --editor will allow to add/change grub stuff; does that sound like what you’re trying to do?

[pauldoo (Paul Richards)]

Yep, so grub2-mkconfig -o /etc/grub2-efi.cfg worked just fine to apply my changes, and Silverblue hasn’t exploded yet.

The rpm-ostree kargs --editor command is applicable only if you are editing kernel arguments. I wasn’t, I wanted to tweak some grub settings.

[bryanmoore]

Well, that’s great to hear and I’m glad things are working…