The configuration file is located on /etc/default/grub.
For configuration documentation, see https://www.gnu.org/software/grub/manual/grub/html_node/Simple-configuration.html.
Make sure to apply grub config changes using:
sudo grub-mkconfig -o /boot/grub/grub.cfgMaking the logs more verbose
Set GRUB_CMDLINE_LINUX="debug loglevel=7"
Explanation below:
GRUB_CMDLINE_LINUX
- Command-line arguments to add to menu entries for the Linux kernel.
GRUB_CMDLINE_LINUX_DEFAULT
- Unless
GRUB_DISABLE_RECOVERYis set to ‘true’, two menu entries will be generated for each Linux kernel: one default entry and one entry for recovery mode. - This option lists command-line arguments to add only to the default menu entry, after those listed in ‘GRUB_CMDLINE_LINUX’.
The difference:
-
Options in
GRUB_CMDLINE_LINUXare always effective. -
Options in
GRUB_CMDLINE_LINUX_DEFAULTare effective ONLY during normal boot (NOT during recovery mode).