RL9 Kernel Parameter Carryover Upon New Kernel Installs

Rocky Linux General
1

RedHat and derivitaves Rockylinux etc…
With BLScfg enabled and in UEFI boot mode RHEL does not provide a
means to automatically update kernel parameters upon kernel updates. Meaning that updates don’t source the Commandline parameters from either /etc/default/grub nor from /boot/grug2/grubenv . From their documentation you are expected to run grub2-mkconfig after a new kernel install to update your parameters to the new kernel. After some searching and assistance from others I discovered that there is a “Backdoor” means of achieving automatic kernel parameters updates by creating a file in /etc/kernel/ called cmdline. You can populate that file with any means convenient to you but most importantly you need to include as the first parameter:
root=UUID=<uuid of your root or boot partition>
and then your other space separated parameters.

Once this file is created with your parameters thus entered now upon
new kernel installs the parameters as defined will be appended to the
new kernel boot line and the updated boot entry in
/boot/loader/entries/

2

You may want to consider using grubby instead (which creates /etc/kernel/cmdline for you). See here.

grubby --update-kernel=ALL --args='someparam=value'
3

I do on my fedora systems but I had no idea it was creating that file also. Most recently I’ve been using grub2-editenv on those systems because it is more widely accepted and gets the job done.
The manpage for grubby never mentions this file. I stumbled upon it reading the code in /usr/lib/kernel/install.d where I found the snippets that solved my issues in my other thread and prompted me to post this more clearly here.
Lots of users have commandline parameters that need to persist upon kernel installs especially if they have special graphics hardware.