What are grub rescue commands?

Grub rescue commands are step-by-step instructions that a person types in a computer command terminal in order to start the machine. These commands are essentials in situations when the drive assignments and partitions have changed or when a new operating system is being installed.

There are two situations that may require the use of grub rescue commands. One when the system boots up and stops at the "grub>" prompt, and the other is when the system stops at the "grub rescue>" prompt. Each of these situations requires the use of particular grub rescue commands in order for the system to continue. The "grub.cfg file" command can be used at the "grub>" prompt to continue the loading process.