====== GRUB ======
**__GR__and __U__nified __B__ootloader** (GRUB) is a common boot tool used in [[Linux]] distros. It handles loading Linux and other operating systems. Apparently you don't really need it anymore, but I'm past the point of wanting to fuck too much with my computer if it's working.

===== Installation =====

==== Re-installation ====

I've come across hard disk trouble a few times that were solved by reinstalling GRUB. For example on booting getting a GRUB prompt with a ''no such partition'' error.

This has typically had to be done via booting with the [[arch_linux]] install USB because it was impossible to boot otherwise. The process is the same as the initial install.

The process is:

  - Boot into the Arch install environment (make sure you're in UEFI mode if your computer supports it. All the following instructions assume UEFI)
  - Use ''lsblk'' to get locations of disks.
  - Mount those under ''/mnt'' and ''/mnt/boot'' as applicable.
  - Use ''arch-chroot'' to get into the mounted stuff and [[archw>GRUB#Installation_2|install GRUB as normal]], eg:
    - ''grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=grub''
    - ''grub-mkconfig -o /boot/grub/grub.cfg''
  - Reboot, cross your fingers.

{{tag>fixes grub guide linux software}}