Linux Boot Process 2

Question 1

Which systemd target is the equivalent of the traditional SysVinit runlevel 3?

Accepted Answer

multi-user.target

Answer

multi-user.target corresponds to runlevel 3 — multi-user, non-graphical mode.

Question 2

What is the purpose of the initramfs (initial RAM filesystem) during the Linux boot process?

Accepted Answer

To provide a temporary root filesystem so the kernel can mount the real root

Answer

initramfs provides a temporary root filesystem in RAM that contains tools needed to mount the actual root filesystem.

Question 3

Which command displays the systemd boot log from the current boot session?

Accepted Answer

journalctl -b

Answer

journalctl -b shows log entries from the current boot; -b 0 is implicit for the latest boot.

Question 4

In GRUB2, which file is the primary human-editable configuration file on most Linux distributions?

Accepted Answer

/etc/default/grub

Answer

/etc/default/grub holds user-editable settings; grub.cfg is auto-generated from it via grub2-mkconfig.

Question 5

What does the kernel parameter 'rd.break' do when added to the boot command line?

Accepted Answer

Drops to a shell just before the real root is switched to

Answer

rd.break breaks into a dracut/initramfs shell just before the switch_root call, useful for emergency root password recovery.

Linux Practice Test