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Quiz — Linux for Cloud & DevOps Fundamentals

Quiz Overview

Assess production Linux skills for Cloud, DevOps, Platform, and SRE roles across the full track.

Attribute Value
Topic Linux for Cloud & DevOps Engineers
Questions 40
Passing score 70% (28 correct)
Estimated time 45–60 minutes
Format Multiple choice (single answer)

How to use this quiz

Attempt each section without peeking. Use Reveal answer only after you commit to a choice.

Older Linux quizzes

Linux Fundamentals and Linux Servers remain available. Prefer this quiz for the rewritten 16-module course.

Learning Objectives

This quiz assesses whether you can:

  • Explain Linux architecture, boot, and FHS
  • Use core commands, filesystem concepts, and permissions
  • Process text and manage processes
  • Operate systemd, storage, networking, and packages
  • Schedule work, read logs, and monitor hosts
  • Apply security, container basics, troubleshooting, and production judgement

Section — Fundamentals & Filesystem (Modules 1–3)

Question 1

What is the Linux kernel primarily responsible for?

Difficulty: Beginner

Options:

  • A. Process scheduling, memory, devices, and system calls
  • B. Providing a graphical desktop theme store
  • C. Replacing DNS on the public internet
  • D. Compiling JavaScript for browsers
Reveal answer

Correct answer: A

The kernel mediates hardware and user-space processes.

Related concepts

  • kernel
  • architecture

Module focus: M1 Fundamentals

Question 2

Ubuntu and Rocky Linux are examples of what?

Difficulty: Beginner

Options:

  • A. Kernels only
  • B. Linux distributions (kernel + userland + packages)
  • C. Firmware boot ROMs
  • D. Container runtimes
Reveal answer

Correct answer: B

A distribution packages the kernel with tools, libraries, and policies.

Related concepts

  • distributions

Module focus: M1 Fundamentals

Question 3

In a typical modern Linux boot, which process is PID 1?

Difficulty: Beginner

Options:

  • A. bash
  • B. sshd
  • C. systemd (on most Cloud/DevOps hosts)
  • D. cron
Reveal answer

Correct answer: C

systemd is the init system and PID 1 on most current server distributions.

Related concepts

  • boot
  • systemd

Module focus: M1 Boot/FHS

Question 4

Which directory traditionally holds host-specific configuration?

Difficulty: Beginner

Options:

  • A. /var
  • B. /proc
  • C. /home
  • D. /etc
Reveal answer

Correct answer: D

FHS places configuration under /etc.

Related concepts

  • FHS

Module focus: M1 Boot/FHS

Question 5

Which command prints the current working directory?

Difficulty: Beginner

Options:

  • A. pwd
  • B. cwd
  • C. whereami
  • D. ls -d
Reveal answer

Correct answer: A

pwd = print working directory.

Related concepts

  • commands

Module focus: M2 Commands

Question 6

Which command follows a growing log file in real time?

Difficulty: Beginner

Options:

  • A. head -f
  • B. tail -f
  • C. cat -f
  • D. less -grow
Reveal answer

Correct answer: B

tail -f follows appended output.

Related concepts

  • tail

Module focus: M2 Commands

Question 7

A symbolic link differs from a hard link because a symlink:

Difficulty: Beginner

Options:

  • A. Shares the same inode and cannot cross filesystems
  • B. Is only available on network filesystems
  • C. Stores a path reference and can point across filesystems
  • D. Always requires root to create
Reveal answer

Correct answer: C

Symlinks are path pointers; hard links share inodes on one filesystem.

Related concepts

  • symlinks
  • inodes

Module focus: M3 Filesystem

Question 8

You suspect inode exhaustion, not block exhaustion. Which check helps most?

Difficulty: Intermediate

Options:

  • A. du -sh / only
  • B. free -h
  • C. uptime
  • D. df -i
Reveal answer

Correct answer: D

df -i reports inode usage per filesystem.

Related concepts

  • inodes
  • df

Module focus: M3 Filesystem

Section — Users, Text, Processes (Modules 4–6)

Question 9

Which command shows your user identity and group memberships?

Difficulty: Beginner

Options:

  • A. id
  • B. whoami -G
  • C. passwd -a
  • D. login
Reveal answer

Correct answer: A

id prints uid, gid, and groups.

Related concepts

  • users

Module focus: M4 Users

Question 10

What does chmod 640 typically grant?

Difficulty: Beginner

Options:

  • A. Owner rwx, group rwx, others rwx
  • B. Owner rw, group r, others none
  • C. Owner r, group rw, others rw
  • D. Sticky bit on a directory only
Reveal answer

Correct answer: B

6=rw, 4=r, 0=none.

Related concepts

  • chmod

Module focus: M4 Permissions

Question 11

The SGID bit on a directory is commonly used to:

Difficulty: Intermediate

Options:

  • A. Make all files world-writable
  • B. Disable ACLs
  • C. Force new files to inherit the directory's group
  • D. Encrypt filenames
Reveal answer

Correct answer: C

SGID on directories preserves group ownership for collaboration.

Related concepts

  • SGID

Module focus: M4 Permissions

Question 12

Which tool is best for field-oriented reporting from columnar text?

Difficulty: Beginner

Options:

  • A. gzip
  • B. chmod
  • C. systemctl
  • D. awk
Reveal answer

Correct answer: D

awk excels at column splitting and reports.

Related concepts

  • awk

Module focus: M5 Text

Question 13

grep -v inverts the match. What does that mean?

Difficulty: Beginner

Options:

  • A. Print lines that do not match the pattern
  • B. Match only verbose log levels
  • C. Search compressed files only
  • D. Ignore binary files silently always
Reveal answer

Correct answer: A

-v selects non-matching lines.

Related concepts

  • grep

Module focus: M5 Text

Question 14

Which command lists processes in a portable snapshot form?

Difficulty: Beginner

Options:

  • A. df -h
  • B. ps aux (or ps -ef)
  • C. ip route
  • D. lsblk
Reveal answer

Correct answer: B

ps snapshots process state.

Related concepts

  • ps

Module focus: M6 Processes

Question 15

You want a process to keep running after logout. A classic approach is:

Difficulty: Intermediate

Options:

  • A. kill -9
  • B. chmod +x
  • C. nohup cmd & (or a systemd unit)
  • D. umask 000
Reveal answer

Correct answer: C

nohup ignores SIGHUP; systemd is preferred for services.

Related concepts

  • nohup
  • signals

Module focus: M6 Processes

Question 16

renice adjusts which attribute of a running process?

Difficulty: Intermediate

Options:

  • A. Filesystem mount options
  • B. SELinux context only
  • C. APT pin priority
  • D. Scheduling nice priority
Reveal answer

Correct answer: D

renice changes nice value for CPU scheduling priority.

Related concepts

  • nice

Module focus: M6 Processes

Section — systemd, Storage, Networking (Modules 7–9)

Question 17

Which command shows whether a unit is active and recent logs summary?

Difficulty: Beginner

Options:

  • A. systemctl status unit
  • B. apt status unit
  • C. cron status unit
  • D. sshd -T unit
Reveal answer

Correct answer: A

systemctl status is the first service triage step.

Related concepts

  • systemctl

Module focus: M7 systemd

Question 18

journalctl -u nginx.service -f does what?

Difficulty: Beginner

Options:

  • A. Formats disks named nginx
  • B. Follows the journal for that unit
  • C. Forces nginx to reload certificates
  • D. Flushes firewall rules
Reveal answer

Correct answer: B

-u filters by unit; -f follows.

Related concepts

  • journalctl

Module focus: M7 systemd

Question 19

systemd timers are often preferred over cron when you need:

Difficulty: Intermediate

Options:

  • A. Only email on success
  • B. GUI calendar popups
  • C. Unit dependencies and journal-integrated runs
  • D. To avoid all logging
Reveal answer

Correct answer: C

Timers integrate with systemd dependencies and journaling.

Related concepts

  • timers

Module focus: M7 Targets/Timers

Question 20

Before creating a filesystem, which inventory command is essential?

Difficulty: Beginner

Options:

  • A. dig
  • B. grep
  • C. last
  • D. lsblk -f
Reveal answer

Correct answer: D

Always identify the correct block device first.

Related concepts

  • lsblk

Module focus: M8 Storage

Question 21

Why mount by UUID in /etc/fstab?

Difficulty: Intermediate

Options:

  • A. Device names like /dev/sdX can change across reboots
  • B. UUIDs encrypt the filesystem automatically
  • C. UUID mounts disable quotas
  • D. Kernel requires UUID for ext4 only
Reveal answer

Correct answer: A

Persistent identifiers avoid wrong-disk mounts.

Related concepts

  • fstab
  • UUID

Module focus: M8 Storage

Question 22

Which LVM command lists logical volumes?

Difficulty: Intermediate

Options:

  • A. ip -br lvs
  • B. lvs
  • C. lsof
  • D. lvscanctl
Reveal answer

Correct answer: B

pvs/vgs/lvs are the core LVM report tools.

Related concepts

  • LVM

Module focus: M8 LVM

Question 23

Which command shows listening TCP/UDP sockets with processes (when permitted)?

Difficulty: Beginner

Options:

  • A. df -T
  • B. chmod -R
  • C. ss -tulpn
  • D. tar -tz
Reveal answer

Correct answer: C

ss replaced much of netstat usage.

Related concepts

  • ss

Module focus: M9 Networking

Question 24

dig +short example.com primarily queries which system?

Difficulty: Beginner

Options:

  • A. LVM metadata
  • B. journald
  • C. SELinux policy store
  • D. DNS
Reveal answer

Correct answer: D

dig is a DNS lookup utility.

Related concepts

  • DNS

Module focus: M9 Networking

Section — Packages, Scheduling, Logging & Monitoring (Modules 10–12)

Question 25

A secure default for SSH server hardening is:

Difficulty: Intermediate

Options:

  • A. Pubkey auth on; password auth off; PermitRootLogin no
  • B. Telnet on port 23 for compatibility
  • C. Empty passwords for automation users
  • D. PermitRootLogin yes with password
Reveal answer

Correct answer: A

Keys + no root password login is a standard baseline.

Related concepts

  • SSH

Module focus: M9 SSH

Question 26

On Debian/Ubuntu, which sequence refreshes indexes then installs a package?

Difficulty: Beginner

Options:

  • A. yum update && yum install
  • B. apt update && apt install pkg
  • C. pacman -Syyu pkg only on Ubuntu
  • D. brew install pkg
Reveal answer

Correct answer: B

apt is the Debian/Ubuntu package workflow.

Related concepts

  • apt

Module focus: M10 Packages

Question 27

dpkg -l is most useful to:

Difficulty: Beginner

Options:

  • A. List block devices
  • B. List listening ports
  • C. List installed Debian packages
  • D. List systemd timers
Reveal answer

Correct answer: C

dpkg queries the local package database.

Related concepts

  • dpkg

Module focus: M10 Packages

Question 28

A user crontab entry runs with whose environment/permissions?

Difficulty: Intermediate

Options:

  • A. Always root regardless of owner
  • B. The kernel keyring daemon
  • C. Nobody and no groups
  • D. The crontab owner's account (with a limited environment)
Reveal answer

Correct answer: D

User crontabs run as that user; PATH is often minimal.

Related concepts

  • cron

Module focus: M11 Scheduling

Question 29

Which systemd unit type is designed to activate another unit on a schedule?

Difficulty: Beginner

Options:

  • A. timer
  • B. mount
  • C. swap
  • D. socket only for HTTP
Reveal answer

Correct answer: A

.timer units activate corresponding services.

Related concepts

  • timers

Module focus: M11 Scheduling

Question 30

Which facility collects and queries structured binary logs on systemd hosts?

Difficulty: Beginner

Options:

  • A. Only /var/log/wtmp
  • B. journald (queried via journalctl)
  • C. mkfs
  • D. parted
Reveal answer

Correct answer: B

journald stores journals; journalctl queries them.

Related concepts

  • journald

Module focus: M12 Logging

Question 31

logrotate is primarily used to:

Difficulty: Beginner

Options:

  • A. Balance LVM extents
  • B. Rotate SSH host keys weekly
  • C. Manage size/retention of log files
  • D. Compress kernel modules
Reveal answer

Correct answer: C

logrotate handles rotation, compression, and retention.

Related concepts

  • logrotate

Module focus: M12 Logging

Question 32

vmstat 1 5 is useful during performance triage because it:

Difficulty: Intermediate

Options:

  • A. Rewrites fstab automatically
  • B. Starts a packet capture
  • C. Disables swap forever
  • D. Samples processes, memory, IO, and CPU over time
Reveal answer

Correct answer: D

vmstat gives a rapid host health pulse.

Related concepts

  • vmstat

Module focus: M12 Monitoring

Section — Security, Containers, Troubleshooting & Production (Modules 13–16)

Question 33

Before enabling UFW on a remote VM, you should first:

Difficulty: Intermediate

Options:

  • A. Allow SSH (OpenSSH) and keep console/out-of-band access
  • B. Delete all users except root
  • C. Disable the network interface
  • D. Set PermitRootLogin yes
Reveal answer

Correct answer: A

Allow administrative access before default deny.

Related concepts

  • UFW
  • firewall

Module focus: M13 Security

Question 34

Fail2Ban typically helps by:

Difficulty: Intermediate

Options:

  • A. Replacing TLS certificates
  • B. Banning hosts that match abusive patterns in logs
  • C. Growing LVM volumes
  • D. Compiling the kernel
Reveal answer

Correct answer: B

Fail2Ban reacts to repeated failures (e.g. SSH).

Related concepts

  • Fail2Ban

Module focus: M13 Security

Question 35

SELinux or AppArmor denials should usually be handled by:

Difficulty: Advanced

Options:

  • A. chmod 777 on /
  • B. Disabling the firewall permanently
  • C. Reading audit/journal denials and fixing labels/profiles properly
  • D. Turning off SSH
Reveal answer

Correct answer: C

Fix policy/labels; avoid blind disable in production.

Related concepts

  • SELinux
  • AppArmor

Module focus: M13 Security

Question 36

Linux containers isolate processes primarily using:

Difficulty: Intermediate

Options:

  • A. Only chroot without kernel help
  • B. Hyper-V on all Linux hosts
  • C. BIOS passwords
  • D. namespaces and cgroups (plus a filesystem like OverlayFS)
Reveal answer

Correct answer: D

Namespaces isolate; cgroups limit; overlay filesystems layer images.

Related concepts

  • namespaces
  • cgroups

Module focus: M14 Containers

Question 37

First commands for a failed systemd service incident?

Difficulty: Intermediate

Options:

  • A. systemctl status and journalctl -u with a time window
  • B. mkfs on the root device
  • C. Randomly chmod -R 777 /etc
  • D. Disable journald
Reveal answer

Correct answer: A

Status + journal is the standard first pass.

Related concepts

  • troubleshooting

Module focus: M15 Troubleshooting

Question 38

High iowait in CPU stats most strongly suggests:

Difficulty: Advanced

Options:

  • A. DNS misconfiguration only
  • B. Tasks waiting on block I/O (disk pressure/latency)
  • C. Too many SSH keys
  • D. Expired apt mirrors only
Reveal answer

Correct answer: B

wa indicates time waiting for I/O.

Related concepts

  • performance
  • iowait

Module focus: M15 Troubleshooting

Question 39

A backup strategy is incomplete without:

Difficulty: Intermediate

Options:

  • A. A colourful dashboard theme
  • B. Disabling checksums for speed
  • C. A tested restore drill (prove recovery)
  • D. Storing secrets in the backup README
Reveal answer

Correct answer: C

Untested backups are assumptions, not recovery capability.

Related concepts

  • backup
  • DR

Module focus: M16 Production

Question 40

Production Linux hardening commonly includes all EXCEPT:

Difficulty: Advanced

Options:

  • A. Least-privilege users and SSH key auth
  • B. Host firewall with default deny inbound
  • C. Patch cadence and monitoring/logging
  • D. World-writable application directories for convenience
Reveal answer

Correct answer: D

World-writable dirs violate least privilege and are not hardening.

Related concepts

  • hardening

Module focus: M16 Production

Answer key (self-mark)

Q Ans Q Ans Q Ans Q Ans
1 A 11 C 21 A 31 C
2 B 12 D 22 B 32 D
3 C 13 A 23 C 33 A
4 D 14 B 24 D 34 B
5 A 15 C 25 A 35 C
6 B 16 D 26 B 36 D
7 C 17 A 27 C 37 A
8 D 18 B 28 D 38 B
9 A 19 C 29 A 39 C
10 B 20 D 30 B 40 D

Distribution: A=10, B=10, C=10, D=10.

If you missed… Revise
Q1–8 Fundamentals, boot, FHS, commands, filesystem tutorials
Q9–16 Users/permissions, text tools, process management
Q17–24 systemd, storage/LVM, networking/SSH
Q25–32 Packages, cron/timers, logging, vmstat/iostat
Q33–40 Firewalls/LSM, containers, triage, hardening/backup