GRUB2 is the latest version of GNU GRUB, the GRand Unified Bootloader. A bootloader is the first software program that runs when a computer starts. It is responsible for loading and transferring control to the operating system kernel.
Normally, GRUB2 will be installed and set up by the installer, Anaconda, during the installation process. You will probably never have to deal with manual installation of GRUB2. However, in certain situations , you will want to install GRUB2 manually, especially if you need to repair the existing GRUB2 installation or you want to change its configuration.
This procedure shows the steps to install GRUB2 on your Master Boot Record (MBR) of your primary hard disk.
1. Install grub2
# yum -y install grub2
2. Create a configuration file for GRUB2.
# grub2-mkconfig -o /boot/grub2/grub.cfg
3. List block devices available on the system. Identify the primary hard disk. Usually, it is the sda device.
4. Install GRUB2 in the MBR of the primary hard disk.
# grub2-install /dev/sda
5. Reboot your computer to boot with the newly installed bootloader.