SUSE Linux Enterprise 15 systems support an "recovery boot" option that can be used
to prevent services from being started. The GRUB_DISABLE_RECOVERY
configuration option in /etc/default/grub should be set to
true to disable the generation of recovery mode menu entries. It is
also required to change the runtime configuration, run:
$ sudo grub2-mkconfig -o /boot/grub2/grub2.cfg