January 23, 2026

Fedora 43 -- Grub

I got interested in this when I wanted to start messing with the grub boot line to enable or disable nouveau during nvidia driver troubleshooting.

Get rid of rhgb

Keep an eye out for this and get rid of it. being able to get rid of this is a nice side-benefit of digging into grub, but not the main purpose.

Change the boot line during boot

When booting, you briefly get a grub screen. You can use arrow keys to go up/down to select which kernel you boot. You can type "e" to edit the current boot line.

Sadly, editing is not vim. You use arrow keys along with the DEL keys to get the result you want. When you are done, you type F10 to actually boot using that line.

As near as I can tell, such changes are not permanent. The next section will talk about how to make permanent changes to the grub setup.

First though, here is what to do to enable nouveau. If you are using the nvidia drivers, you will find a boot line that contains the following: 

rd.driver.blacklist=nouveau modprobe.blacklist=nouveau
Get rid of this if you want to run nouveau. You can leave your nvidia drivers in place.
I found this: 
rd.driver.blacklist=nouveau,nova_core modprobe.blacklist=nouveau,nova_core
rd.driver.blacklist=nova_core modprobe.blacklist=nova_core
I changed my bootline to the second thing above, keeping nova_core blacklisted. This worked. What nova_core is, is an experimental replacement for nouveau that Red Hat is working on.

Making permanent changes to the grub setup

In the old days, you would edit a file in /boot/grub2 -- but that is not what you do these days.

These days you edit the file /etc/default/grub, then run: 

su
cd /etc/default
cp grub grub.ORIG
vi grub
grub2-mkconfig -o /boot/grub2/grub.cfg
Have any comments? Questions? Drop me a line!

Adventures in Computing / tom@mmto.org