Booting grub, not picking up changes to grub.cfg file

Issues related to applications and software problems and general support
Post Reply
jimbux
Posts: 59
Joined: 2011/11/28 18:23:13
Contact:

Booting grub, not picking up changes to grub.cfg file

Post by jimbux » 2021/02/14 21:05:08

Can anyone please explain to me why when I make changes to /etc/default/grub (I removed some blacklist nouveau entries and nvidia stuff), then after I've run...

Code: Select all

grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg
...and reboot, then 'e' (edit) the CentOS entry, that "rd.driver.blacklist-nouveau modprobe.blacklist=nouveau nvidia-drm.modeset=1" are still present in the "linux ($root)/vmlinuz-4.18<etc>" line?

or ever better, how do I fix it? Thanks tons folks!

User avatar
TrevorH
Forum Moderator
Posts: 30344
Joined: 2009/09/24 10:40:56
Location: Brighton, UK

Re: Booting grub, not picking up changes to grub.cfg file

Post by TrevorH » 2021/02/14 21:22:23

Is your system in UEFI mode? Does /sys/firmware/efi exist?
CentOS 6 died in November 2020 - migrate to a new version!
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 is dead, do not use it.
Full time Geek, part time moderator. Use the FAQ Luke

jimbux
Posts: 59
Joined: 2011/11/28 18:23:13
Contact:

Re: Booting grub, not picking up changes to grub.cfg file

Post by jimbux » 2021/02/14 21:37:18

I am in UEFI mode, and /sys/firmware/efi does exist.

I have a dual boot setup - win10 and Centos 8.3 (up to date). I have been messing around trying to get Nvidia drivers installed, so I installed, then uninstalled some packages, not sure if in uninstalling the Nvidia drivers (both elrepo rpmfusion approaches) that something didn't get cleanly uninstalled. (if that's any help).

Thanks Trevor.

jimbux
Posts: 59
Joined: 2011/11/28 18:23:13
Contact:

Re: Booting grub, not picking up changes to grub.cfg file

Post by jimbux » 2021/02/14 23:11:13

Hey Trevor - thanks for your time so far, I managed to get things "back to normal" by ...

Code: Select all

su -
dnf reinstall \*
I have no idea what got updated that fixed my issues, but the system boots up with a normal set of arguments to the linux line via the grub boot menu.

Thanks again. J.

User avatar
jlehtone
Posts: 3349
Joined: 2007/12/11 08:17:33
Location: Finland

Re: Booting grub, not picking up changes to grub.cfg file

Post by jlehtone » 2021/02/15 09:15:26

Note: CentOS 8 does use BootLoaderSpec https://systemd.io/BOOT_LOADER_SPECIFICATION/

You can set variables in /etc/default/grub and grub2-mkconfig will write /boot/efi/EFI/centos/grub.cfg for you.
Perhaps even update /boot/efi/EFI/centos/grubenv

However, the BLS has the "real" entries in /boot/loader/entries
(Re)installing kernel runs also 'grubby', which updates those.
Or something like that.

Post Reply

Return to “CentOS 8 - General Support”