How to access Rescue mode (runlevel 1) in Linux
I frequently find need to perform maintenance on the filesystem of one of my dozen or so physical computers. Many maintenance tasks require the system to be running the Rescue.target, formerly, runlevel 1. There are two methods you can use to enter Rescue mode.
An introduction to GRUB2 configuration for your Linux machine
Learn how the GRUB boot loader works to prepare your system and launch your operating system kernel.