Linux+ V7 Boot and Startup Troubleshooting Quiz

1. Which systemd unit type handles mount points during boot?

.service

.mount

.target

.socket

2. Which parameter would you pass to the kernel at boot to skip fsck checks and boot immediately?

Nofail

Nofsck

Fsck=no

Skip_fsck

3. A disk UUID changes after hardware changes, causing boot failure. How do you fix fstab without reinstalling?

Use blkid to get new UUIDs and update /etc/fstab entries

Boot with a live USB and edit fstab

Switch fstab to use device names instead of UUIDs

All of the above work

4. What is the relationship between /etc/systemd/system/ and /usr/lib/systemd/system/?

/etc/ contains system defaults, /usr/lib/ contains local overrides

/etc/ contains local unit overrides, /usr/lib/ contains package defaults

They are identical and redundant

Only /usr/lib/ is used during boot

5. During boot, the system hangs after 'Starting Load Kernel Modules.' Where should you investigate first?

/etc/modprobe.d/ for problematic module configs

Dmesg for kernel module errors

/var/log/messages for systemd-modules-load errors

All of the above

6. What does the 'GRUB_TIMEOUT' parameter control in /etc/default/grub?

Maximum boot time allowed

Seconds to wait before booting default entry

Password timeout duration

Kernel load timeout

7. A service is enabled but fails to start during boot. Which command shows the detailed error?

Journalctl -xe

Systemctl status service-name

Systemctl enable service-name

Both a and b provide useful information

8. After editing GRUB configuration, which command regenerates the actual GRUB menu file?

Grub-update

Grub-mkconfig -o /boot/grub/grub.cfg

Update-grub

Both b and c are correct

9. What is the purpose of the GRUB2 configuration file /etc/default/grub?

Define GRUB menu timeout and default boot entry

Store bootloader password

List all installed kernels

Configure network boot settings

10. You modify /etc/fstab but the system now fails to boot. How would you recover without reinstalling?

Boot into single-user mode and edit fstab

Use a live USB and mount the filesystem to fix fstab

Boot with 'rd.break' to access dracut shell

All of the above are viable approaches

11. Which bootloader file is typically the first stage of the BIOS boot process on x86 systems?

MBR (Master Boot Record)

GRUB2 configuration

Kernel image

Initramfs

12. A system boots into emergency mode because fsck fails. Which command would you use to manually run fsck on /dev/sda1?

Fsck /dev/sda1

Fsck -y /dev/sda1

E2fsck /dev/sda1

All of the above are valid

13. What does the 'ro' parameter in the GRUB kernel line indicate?

Run in offline mode

Root filesystem mounted read-only

Reboot on error

Require optimization

14. When troubleshooting boot issues, where would you find detailed kernel and initialization messages?

/var/log/messages

Dmesg output or /var/log/kern.log

/var/log/auth.log

/var/log/syslog only

15. A service fails to start at boot. Which systemd target defines the default boot state?

Multi-user.target

Default.target

Graphical.target

System.target

16. You cannot access the GRUB menu during boot. Which key combination typically interrupts the boot to access GRUB?

Shift or Esc

F2 or F12

Ctrl+Alt+Del

Tab or Space

17. What is the primary purpose of the initramfs in the Linux boot process?

Load the kernel into memory

Provide a minimal filesystem to mount the root partition

Configure network settings

Start the display manager

18. Which kernel parameter would you add to the GRUB boot line to enable single-user (emergency) mode?

Rescue

Single

Emergency

Debug

19. A system fails to boot and drops to a dracut emergency shell. Which file should you check first?

/boot/grub/grub.cfg

/etc/fstab

/etc/systemd/system-generators

/var/log/boot.log

20. What command would you use to check the status of a systemd service named 'networking'?

Service networking status

Systemctl status networking

Chkconfig networking

Init.d networking check

Linux+ V7 Troubleshooting Boot and Startup Issues Quiz