Question

Explain Linux Boot Sequence.

Answer 1

There are six levels of a Linux Boot Sequence. These are as follows:

• BIOS: Full form of BIOS is Basic Input or Output System that performs integrity checks and it will search and load and then it will execute the bootloader.
• MBR: MBR means Master Boot Record. MBR contains the information regarding GRUB and executes and loads this bootloader.
• GRUB: GRUB means Grand Unified Bootloader. In case, many kernel images are installed on your system then you can select which one you want to execute.
• Kernel: Root file system is mounted by Kernel and executes the /sbin/init program.
• Init: Init checks the file /etc/inittab and decides the run level. There are seven-run levels available from 0-6. It will identify the default init level and will load the program.
• Runlevel programs: As per your default settings for the run level, the system will execute the programs.