Have to do a grubby --update-kernel to add correct options after every IO upgrade

Hello team,
I was playing around with the IOS several major versions back and must have messed up my default GRUB definitions. Since then, I have had to do a “grubby --update-kernel” to add the correct options after any type of kernel upgrade.
Can anyone tell me how I can correct this?
Right now, I’m running 6.3.8-200.fc38.x86_64 and the commands I need to run after every upgrade:

sudo grubby --update-kernel=“/boot/vmlinuz-x.y.z-a00.fc38.x86_64” --args="root="UUID=fad3c99c-dac7-48fd-94f3-ebaed206163e

sudo grubby --update-kernel=“/boot/vmlinuz-x.y.z-a00.fc38.x86_64” --args="ro rootflags=subvol=root rhgb quiet "

Before entering these commands, after an upgrade, the OS does not boot and appears to go into diagnostic mode.

Any help would be appreciated. Please remember that I am not a power user and would need step by step instructions.

Hey Gary, read this post and LMK if it helps!


It looks like the same issue. Any idea when a fix will be done?

PS - thanks for your response!

Please post the content of /etc/default/grub so we may see what the default config may be that grub works with for creating the boot entries. Also /etc/kernel/cmdline

1 Like

Here you go:
GRUB_DISTRIBUTOR=“$(sed ‘s, release .*$,g’ /etc/system-release)”

/etc/kernel/cmdline is empty

You said you are using the 6.3.8 kernel.

Now please post the output of
sudo cat /boot/loader/entries/*6.3.8*.conf and sudo grub2-editenv - list
It would seem that the options there may be off.

may also want to check:
sudo grubby --info=ALL

I always end up doing something like sudo bash -c "cat /boot/loader/entries/*.6.3.8*.conf" because of permission being denied otherwise.

I would suggest to fix the GRUB_CMDLINE_LINUX=“rhgb quiet” entry, and when you run

sudo grub2-mkconfig -o /boot/grub2/grub.cfg

it should fix /etc/kernel/cmdline and the option entries in /boot/loader/entries/*.

/etc/kernel/cmdline is use to set the option line when upgrading the kernel.

This has been reported in system fails to boot after installing new kernel, after using grubby, and unfortunately there has been no response to the ticket. You might update the ticket indicating you had the same issue, that may or may not get it more attention. As I mentioned in the previous post, apparently this is a known issue, that happens from time to time, but never gets resolved.