LPIC-1 System Architecture Practice Test 5 — 15 Questions

Question 1

To add a kernel parameter temporarily to the kernel command line at boot, what key should be pressed in the GRUB menu?

Accepted Answer

e. Pressing 'e' in the GRUB menu enters the edit mode for the selected boot entry, allowing you to temporarily modify kernel parameters on the command line (e.g., adding 'single' for single-user mode or 'nomodeset' for graphics issues). These changes apply only to the current boot and are not saved to the GRUB configuration file.

Answer

b

Answer

r

Answer

c

Question 2

A system has multiple CPUs but only one is being used. Which file under /sys/ can be checked to verify CPU online status?

Accepted Answer

/sys/devices/system/cpu/cpu0/online. /sys/devices/system/cpu/cpu0/online is the sysfs file that directly shows the online status of CPU 0. Reading this file returns '1' if the CPU is online and '0' if it is offline, allowing per-CPU verification. The question specifies checking a file under /sys/, and this path is the standard sysfs interface for CPU hotplug status.

Answer

/sys/devices/system/cpu/online

Answer

/proc/cpuinfo

Answer

/sys/class/cpu

Question 3

Which TWO of the following are valid methods to list currently loaded kernel modules?

Accepted Answer

lsmod. B (lsmod) is correct because it reads the /proc/modules file and formats the output in a human-readable table, listing all currently loaded kernel modules. D (cat /proc/modules) is also correct because /proc/modules is the kernel interface that directly exposes the list of loaded modules with their size, usage count, and dependent modules.

Answer

dmesg | grep module

Answer

modprobe -l

Answer

modinfo

Question 4

Which TWO commands can be used to set the default boot target (runlevel) in systemd?

Accepted Answer

ln -sf /lib/systemd/system/multi-user.target /etc/systemd/system/default.target. Creating a symbolic link from `/lib/systemd/system/multi-user.target` to `/etc/systemd/system/default.target` directly sets the default boot target in systemd. This is the traditional method that overrides the default target by pointing the `default.target` symlink to the desired target unit, which systemd reads at boot to determine the runlevel.

Answer

systemctl isolate multi-user.target

Answer

systemctl default multi-user.target

Answer

systemctl enable multi-user.target

Question 5

Which THREE of the following are valid sources to configure GRUB?

Accepted Answer

/boot/grub/grub.cfg. C is correct because `/boot/grub/grub.cfg` is the primary configuration file generated by GRUB 2 (the default bootloader on modern Linux distributions). It is automatically created by running `update-grub` or `grub-mkconfig`, which reads settings from `/etc/default/grub` and scripts in `/etc/grub.d/`. This file contains the actual menu entries and boot directives used at boot time.

Answer

/boot/grub/menu.lst

Answer

/etc/grub.conf

Question 6

A system administrator notices that after updating the kernel, the system fails to boot. The administrator wants to boot the previous kernel. Which GRUB menu option should be selected?

Accepted Answer

Advanced options for Ubuntu. The 'Advanced options for Ubuntu' GRUB menu entry provides access to a submenu listing all installed kernel versions, allowing the administrator to select and boot the previous kernel. This is the standard method to revert to a known-good kernel after a failed update, as GRUB dynamically generates entries for each kernel found in /boot.

Answer

Memory test

Answer

Recovery mode

Answer

Boot from first hard disk

Question 7

A Linux system using systemd fails to reach the default target after a recent change. The administrator wants to boot into a minimal environment to troubleshoot. Which kernel parameter should be added at the GRUB prompt?

Accepted Answer

systemd.unit=rescue.target. Systemd uses `systemd.unit=rescue.target` to boot into a minimal single-user environment with essential services, which is ideal for troubleshooting boot failures. This parameter overrides the default target at the GRUB prompt, allowing the administrator to diagnose and fix the issue without loading the full graphical or multi-user target.

Answer

single

Answer

init=/bin/bash

Answer

systemd.unit=emergency.target

Question 8

On a systemd-based system, which file is NOT used for system initialization?

Accepted Answer

/etc/inittab. /etc/inittab is the configuration file used by the traditional SysV init system to define runlevels and control terminal getty processes. On a systemd-based system, systemd does not read /etc/inittab; instead, it uses unit files and targets to manage system initialization, making this file unused for that purpose.

Answer

/etc/fstab

Answer

/etc/systemd/system/default.target

Answer

/lib/systemd/system/sysinit.target

Question 9

Which systemd target corresponds to the traditional runlevel 3?

Accepted Answer

multi-user.target. In systemd, the 'multi-user.target' corresponds to the traditional SysV runlevel 3, which provides a multi-user, non-graphical environment with networking enabled. This target is the default for headless servers and is equivalent to the old /etc/inittab runlevel 3.

Answer

graphical.target

Answer

emergency.target

Answer

rescue.target

Question 10

An administrator wants to add a kernel parameter 'quiet splash' to the default boot entry. Which file should be edited?

Accepted Answer

/etc/default/grub. The correct file to edit is /etc/default/grub because it is the main configuration file for GRUB 2 where kernel boot parameters like 'quiet splash' are defined in the GRUB_CMDLINE_LINUX_DEFAULT variable. After editing this file, the administrator must run update-grub (or grub-mkconfig) to regenerate the actual boot configuration file /boot/grub/grub.cfg.

Answer

/etc/grub.d/00_header

Answer

/etc/grub.conf

Answer

/boot/grub/grub.cfg

Question 11

A system boots in UEFI mode, and the administrator wants to add a new kernel entry to the EFI boot manager. Which tool should be used?

Accepted Answer

efibootmgr. In UEFI mode, the system's boot manager is stored in NVRAM, and `efibootmgr` is the standard Linux tool for creating, deleting, and modifying boot entries in the UEFI Boot Manager. It directly manipulates the UEFI Boot Manager variables (e.g., BootOrder, Boot####) via the efivars kernel interface, allowing the administrator to add a new kernel entry without relying on a bootloader like GRUB.

Answer

grub2-install

Answer

lilo

Answer

mknbi

Question 12

After connecting a USB device, the system does not create a device node in /dev. Which command can be used to trigger udev to re-evaluate the device?

Accepted Answer

udevadm trigger. The correct command is `udevadm trigger`. This command causes udev to re-evaluate all devices by simulating kernel uevents, which forces udev to process rules and create device nodes in /dev for devices that were missed or not properly initialized.

Answer

modprobe

Answer

udevadm control --reload

Answer

udevadm settle

Question 13

Which command displays information about currently loaded kernel modules?

Accepted Answer

lsmod. The `lsmod` command reads the `/proc/modules` file to display a list of all currently loaded kernel modules, showing their name, size, usage count, and dependent modules. This is the standard tool for querying the current module state in the Linux kernel.

Answer

insmod

Answer

modinfo

Answer

modprobe -l

Question 14

Which TWO of the following are valid methods to view kernel messages on a systemd-based system?

Accepted Answer

journalctl -k. On systemd-based systems, the `journalctl -k` command displays kernel messages from the systemd journal, which is the default logging system. The `-k` flag specifically filters for kernel messages, making it a direct and valid method to view kernel logs.

Answer

lsmod

Answer

cat /var/log/syslog

Answer

grub-mkconfig

Question 15

Which THREE of the following are valid systemd targets?

Accepted Answer

rescue.target. A is correct because `rescue.target` is a standard systemd target that provides a minimal single-user environment for system recovery, similar to single-user mode in SysV init. It is a valid target used to boot into a rescue shell with essential services.

Answer

always.target

Answer

runlevel4.target