Linux Boot Process 3

Question 1

Which kernel parameter would you add to a GRUB2 boot entry to boot Linux into emergency mode?

Accepted Answer

systemd.unit=emergency.target

Answer

Passing systemd.unit=emergency.target on the kernel command line tells systemd to boot into emergency.target.

Question 2

What does UEFI Secure Boot verify during the boot process?

Accepted Answer

That bootloader and kernel are signed with trusted cryptographic keys

Answer

Secure Boot uses cryptographic signatures to verify that the bootloader and kernel haven't been tampered with.

Question 3

Which file does the kernel read to determine the location of the initial RAM disk image?

Accepted Answer

The bootloader passes it as a kernel parameter (initrd=)

Answer

The bootloader (e.g., GRUB2) passes the initrd/initramfs path to the kernel via the initrd= boot parameter.

Question 4

In a system using SysVinit, which script is executed first after the kernel mounts the root filesystem?

Accepted Answer

/sbin/init

Answer

/sbin/init is PID 1 and the first process executed by the kernel after root filesystem mount in SysVinit systems.

Question 5

What is the role of the MBR (Master Boot Record) in legacy BIOS booting?

Accepted Answer

It contains the first-stage bootloader and partition table

Answer

The MBR is the first 512 bytes of the disk, containing the first-stage bootloader code and the partition table.

Linux Practice Test