$ Linux Command

System

grub2-set-default

Set the default boot entry for GRUB2.

grubbootdefaultkernelbootloader

Additional Notes

grub2-set-default sets the default boot entry for the next system start in GRUB2. The default entry is identified by its menu entry name, a numeric index (0-based from the top of the menu), or by the string saved to maintain the last-booted entry.

The command writes the selected entry identifier to the GRUB environment block file, which GRUB reads at boot time. Unlike manually editing grub.cfg, this change persists across kernel updates and GRUB reconfigurations when GRUB_DEFAULT=saved is set in /etc/default/grub.

Syntax

grub2-set-default entry

Parameters

  • entry: The default GRUB menu entry. Can be a numeric index (0, 1, 2, ...), a menu entry name string, or the keyword saved.

Common Options

  • --version: Show version information.
  • --help: Display help.

Examples

sudo grub2-set-default 0

Set the first menu entry as the default.

sudo grub2-set-default "Advanced options for GNU/Linux>Linux 5.15.0-generic"

Set a submenu entry as the default using the full menu path with > separators.

sudo grub2-set-default saved

Set GRUB to boot the last-selected entry.

Practical Notes

  • The change only takes effect if GRUB_DEFAULT=saved is set in /etc/default/grub. Otherwise, grub2-set-default has no effect.
  • After changing /etc/default/grub, run update-grub or grub2-mkconfig -o /boot/grub2/grub.cfg to apply the change.
  • Numeric entries are 0-based. The first menu entry is index 0. Submenu entries can be addressed using > separators.
  • Run grub2-editenv list to verify the stored default entry after setting it.
  • On non-RHEL distributions, the command may be named grub-set-default (without the 2).