====== Default Kernel ======

==== List all available kernel ====
<code bash>
sudo awk -F\' '/menuentry / {print $2}' /boot/grub2/grub.cfg
</code>

:!: Check if all the kernels listed in order and properly set the version (latest on top) if not generate config again.

==== Re-Generate config ====
<code bash>
grub2-mkconfig -o /boot/grub2/grub.cfg
</code>

:!: Redo the previous step and confirm all are listed as expected.

==== Check default kernel ====
<code bash>
grub2-editenv list
</code>

:!: The first item in the list denote entry '0'

==== Set default kernel ====
<code bash>
grub2-set-default 0
</code>

:!: This will set first entry in list to default

==== Change kenel command line option ====

One should change
<code bash>
vi /etc/default/grub
# Change your addition / removal here
GRUB_CMDLINE_LINUX
</code>

==== Grubby way to change ====
<code bash>
grubby --set-default /boot/vmlinuz-4.18.0-240.15.1.el8_3.x86_64
</code>