Update kernel options via grub

• Edit file /etc/default/grub with necessary change
• Finally run grub2-mkconfig -o /boot/grub2/grub.cfg (on rhel, centos) or update-grub on debian, ubuntu
  • if it doesn't work try adding option --update-bls-cmdline to grub2-mkconfig
  • for efi the path could be different: ``