How to Install GRUB Boot Loader
This article describes necessary steps for installing and configuring the GRUB boot loader to a software-based RAID1 array.
Description: Configure and install the GRUB boot loader to a Software-based RAID array. This guide assumes you have chosen the simplest RAID1 setup.
Install the GRUB boot loader
NOTE:
The Debian OS installer by default only installs the GRUB boot loader to the main hard disk in the software-based RAID array. It is best to install the boot loader to all disks in the RAID1 array in the event that (1) a drive failure occurs and you need to boot from the secondary drive or (2) due to swapping hard drive connections physically in the chassis, the other drive becomes the primary drive.
Access the server console via a direct keyboard/mouse/monitor connection to the server, SSH, or via Debian Control Panel.
Log in with the root user, or another administrative user on the system. This is the password set in the "Set Up Users and Passwords" section of the "Step By Step Debian 12 Installation" guide.
Initiate the process of installing the GRUB boot loader. Depending on the configuration of your server BIOS, you will need to execute following commands:
dpkg-reconfigure grub-pc
After entering in the above command at the terminal, press “Enter“ key
From the "Configuring grub-pc", leave the "linux command line:" text field blank, then press the "Enter" key.
From the "Configuring grub-pc" screen, type the word "quiet" into the "linux default command line:" text field, then press the "Enter" key.
From the "Configuring grub-pc" (or the "configuring grub-efi-amd64" if UEFI) screen, select every physical drive you added to the RAID1 array when installing the OS to the RAID array, then press the "Enter" key.
Reboot the debian server with the following command:
shutdown -r now