Practice Test XK0-006: CompTIA Linux+

Questions: 249
Release Date: 07/2026
Job Role: Linux Administrator
Language: English

The XK0-006 practice test contains 249 questions and covers the following objectives:

1.0 System Management - 70 questions

1.1 Explain basic Linux concepts.

• Basic boot process: bootloader configuration files, kernel parameters, initrd, PXE
• Filesystem Hierarchy Standard (FHS): /, /bin, /boot, /dev, /etc, /home, /lib, /proc, /sbin, /tmp, /usr, /var
• Server architectures: AArch64, RISC-V, x86, x86_64/AMD64
• Distributions: RPM-based, dpkg-based
• Graphical User Interface (GUI): display managers, window managers, X Server, Wayland
• Software licensing: open source, free software, proprietary, copyleft

1.2 Summarize Linux device management concepts and tools.

• Kernel modules: depmod, insmod, lsmod, modinfo, modprobe, rmmod
• Device management: dmesg, dmidecode, ipmitool, lm_sensors, lscpu, lshw, lsmem, lspci, lsusb
• initrd management: dracut, mkinitrd
• Custom hardware: embedded systems, GPU use cases (nvtop)

1.3 Given a scenario, manage storage in a Linux system.

• Logical Volume Manager (LVM): logical volumes (lvchange, lvcreate, lvdisplay, lvremove, lvresize/lvextend, lvs), volume groups (vgchange, vgcreate, vgdisplay, vgexport, vgextend, vgimport, vgremove, vgs, vgscan), physical volumes (pvcreate, pvdisplay, pvmove, pvremove, pvresize, pvs, pvscan)
• Partitions: blkid, fdisk/gdisk, growpart, lsblk, parted
• Filesystems: xfs, ext4, btrfs, tmpfs
• Utilities: df, du, fio, fsck, mkfs, resize2fs, xfs_growfs, xfs_repair
• RAID: /proc/mdstat, mdadm
• Mounted storage: mounting (/etc/fstab, /etc/mtab, /proc/mounts, autofs, mount, umount), mount options (noatime, nodev, nodiratime, noexec, nofail, nosuid, remount, ro, rw), network mounts (NFS, SMB/Samba)
• Inodes

1.4 Given a scenario, manage network services and configurations on a Linux server.

• Network configuration: /etc/hosts, /etc/resolv.conf, /etc/nsswitch.conf
• NetworkManager: nmcli, nmconnect
• Netplan: netplan apply, netplan status, netplan try, /etc/netplan configuration files
• Common network tools: arp, curl, dig, ethtool, hostname, ip (ip address, ip link, ip route), iperf3, mtr, nc, nmap, nslookup, ping/ping6, ss, tcpdump, tracepath, traceroute

1.5 Given a scenario, manage a Linux system using common shell operations.

• Common environmental variables: DISPLAY, HOME, PATH, PS1, SHELL, USER
• Paths: absolute (~, /), relative (., .., -)
• Shell environment configurations: .bashrc, .bash_profile, .profile
• Channel redirection: <, >, <<, >>, |, stdout, stderr, stdin, here docs (<<<)
• Basic shell utilities: !, !!, alias, awk, bc, cat, cut, echo, grep, head, history, less, more, printf, sed, sort, source, tail, tee, tr, uname, uniq, wc, xargs
• Text editors: vi/vim, nano

1.6 Given a scenario, perform backup and restore operations for a Linux server.

• Archiving: cpio, tar
• Compression tools: 7-Zip, bzip2, gzip, unzip, xz
• Other tools: dd, ddrescue, rsync, zcat, zgrep, zless

1.7 Summarize virtualization on Linux systems.

• Linux hypervisors: QEMU, KVM
• Virtual machines: paravirtualized drivers, VirtIO, disk image operations (convert, resize, image properties), VM states, nested virtualization
• VM operations: resources (storage, RAM, CPU, network), baseline image templates, cloning, migrations, snapshots
• Bare metal vs. virtual machines
• Network types: bridged, NAT, host-only/isolated, routed, open
• Virtual machine tools: libvirt, virsh, virt-manager

2.0 Services and User Management - 66 questions

2.1 Given a scenario, manage files and directories on a Linux system.

• Utilities: cd, cp, diff, file, find, ln, locate, ls, lsof, mkdir, mv, pwd, rm, rmdir, sdiff, stat, touch
• Links: symbolic link, hard link
• Device types in /dev: block devices, character devices, special character devices

2.2 Given a scenario, perform local account management in a Linux environment.

• Add: adduser, groupadd, useradd
• Delete: deluser, groupdel, userdel
• Modify: chsh, groupmod, passwd, usermod
• Lock: chage, passwd, usermod
• Expiration: configuration files, chage
• List: getent passwd, groups, id, last, lastlog, w, who, whoami
• User profile templates: /etc/profile, /etc/skel
• Account files: /etc/group, /etc/passwd, /etc/shadow
• Attributes: UID, GID, EUID, EGID
• User accounts vs. system accounts vs. service accounts; UID range

2.3 Given a scenario, manage processes and jobs in a Linux environment.

• Process verification: /proc/<PID>, atop, htop, lsof, mpstat, pidstat, ps, pstree, strace, top
• Process ID: PPID, PID
• Process states: running, blocked, sleeping, stopped, zombie
• Priority: nice, renice
• Process limits
• Job and process management: &, bg, Ctrl+c, Ctrl+d, Ctrl+z, exec, fg, jobs, kill, killall, nohup, pkill, signals (1 HUP, 9 KILL, 15 TERM)
• Scheduling: anacron, at, crontab

2.4 Given a scenario, configure and manage software in a Linux environment.

• Installation, update, and removal: repositories, source, package dependencies and conflicts, package managers, language-specific managers (pip, cargo, npm)
• Repository management: enabling/disabling, third-party, GPG signatures
• Package and repository exclusions
• Update alternatives
• Software configuration
• Sandboxed applications
• Basic configurations of common services: DNS, NTP/PTP, DHCP, HTTP (Apache httpd, Nginx), SMTP, IMAP4

2.5 Given a scenario, manage Linux using systemd.

• Systemd units: services, timers, mounts, targets
• Utilities: hostnamectl, resolvectl, sysctl, systemctl, systemd-analyze, systemd-blame, systemd-resolved, timedatectl
• Managing unit states: daemon-reload, disable, edit, enable, mask, reload, restart, start, status, stop, unmask

2.6 Given a scenario, manage applications in a container on a Linux server.

• Runtimes: runC, Podman, containerd, Docker
• Image operations: pulling images, building images (Dockerfile: ENTRYPOINT, CMD, USER, FROM), pruning, tags, layers
• Container operations: read logs, map volumes, start/stop, inspect, delete, run, exec, pruning, tags, environmental variables
• Volume operations: create, mapping, pruning, SELinux context, overlay
• Container networks: create network, port mapping, pruning, network types (macvlan, ipvlan, host, bridge, overlay, none)
• Privileged vs. unprivileged containers

3.0 Security - 48 questions

3.1 Summarize authorization, authentication, and accounting methods.

• Polkit
• Pluggable Authentication Modules (PAM)
• SSSD/Winbind realm
• LDAP
• Kerberos
• Samba
• Logging: journalctl, rsyslog, logrotate, /var/log
• System audit: audit.rules, auditd

3.2 Given a scenario, configure and implement firewalls on a Linux system.

• firewalld: firewall-cmd, runtime vs. permanent, rich rules, zones, ports vs. services
• Uncomplicated Firewall (ufw): ports vs. services
• nftables, iptables, ipset, Netfilter module
• Address translation: NAT, PAT, DNAT, SNAT
• Stateful vs. stateless
• IP forwarding: net.ipv4.ip_forward

3.3 Given a scenario, apply operating system hardening techniques on a Linux system.

• Privilege escalation: sudo (/etc/sudoers, NOEXEC, NOPASSWD, /etc/sudoers.d, visudo, sudo -i, wheel group, sudo group), su -
• File attributes: chattr, lsattr (immutable, append only)
• Permissions: file permissions (chgrp, chmod octal/symbolic, chown), special permissions (sticky bit, setuid, setgid), umask
• Access control: ACLs (setfacl, getfacl), SELinux (restorecon, semanage, chcon, ls -Z, getenforce, setenforce, getsebool, setsebool, audit2allow, sealert, states: enforcing/permissive/disabled)
• Secure remote access: SSHD (key vs. password auth, SSH tunneling, PermitRootLogin, X forwarding, AllowUsers, AllowGroups), SSH agent, SFTP (chroot), fail2ban
• Avoid insecure access services: Telnet, FTP, TFTP
• Disabling unused file systems
• Removal of unnecessary SUID permissions
• Secure boot: UEFI

3.4 Explain account hardening techniques and best practices.

• Passwords: complexity, length, expiration, reuse, history
• Multifactor authentication (MFA)
• Checking existing breach lists
• Restricted shells: /sbin/nologin, /bin/rbash
• pam_tally2
• Avoid running as root

3.5 Explain cryptographic concepts and technologies in a Linux environment.

• Data at rest: file encryption (GPG), filesystem encryption (LUKS2, Argon2)
• Data in transit: OpenSSL, WireGuard, LibreSSL, TLS protocol versions
• Hashing: SHA-256, HMAC
• Removal of weak algorithms
• Certificate management: trusted root certificates (no-cost, commercial)
• Avoiding self-signed certificates

3.6 Explain the importance of compliance and audit procedures.

• Detection and response: anti-malware, indicators of compromise (IOC)
• Vulnerability scanning: CVEs, CVSS, backporting patches, service misconfigurations, tools (port scanners, protocol analyzers)
• Standards and audit: OpenSCAP, CIS Benchmarks
• File integrity: AIDE, rkhunter, signed package verification, installed file verification
• Secure data destruction: shred, badblocks -w, dd if=/dev/urandom, cryptographic destruction
• Software supply chain
• Security banners: /etc/issue, /etc/issue.net, /etc/motd

4.0 Automation, Orchestration, and Scripting - 39 questions

4.1 Summarize the use cases and techniques of automation and orchestration in a Linux environment.

• Infrastructure as code: Ansible (playbooks, inventory, modules, ad hoc, collections, facts, agentless), Puppet (classes, certificates, modules, facts, agent/agentless), OpenTofu (provider, resource, state, API)
• Unattended deployment: Kickstart, Cloud-init
• CI/CD: version control, shift left testing, GitOps, pipelines, DevSecOps
• Deployment orchestration: Kubernetes (ConfigMaps, Secrets, Pods, Deployments, Volumes, Services, Variables), Docker Swarm (service, nodes, tasks, networks, scale), Docker/Podman Compose (compose file, up/down, logs)

4.2 Given a scenario, perform automated tasks using shell scripting.

• Expansion: parameter expansion (${var}), command substitution ($(foo), `foo`), subshell ((foo))
• Functions
• IFS/OFS
• Conditional statements: if, case
• Looping statements: until, for, while
• Interpreter directive: #!
• Comparisons: numerical (-eq, -ge, -gt, -le, -lt, -ne), string (>, <, ==, =, =~, !=, <=, >=)
• Regular expressions: [[ $foo =~ regex ]]
• Test: !, -d, -f, -n, -z
• Variables: environmental, arguments, assignments (alias, export, local, set, unalias, unset), return codes ($?)

4.3 Summarize Python basics used for Linux system administration.

• Setting up a virtual environment
• Built-in modules
• Installing dependencies
• Python fundamentals: indentations, current versions, data types and structures (boolean, dictionary, floating point, integer, list, string), extensible using modules and packages
• PEP 8 best practices

4.4 Given a scenario, implement version control using Git.

• .gitignore, add, branch, checkout, clone, commit, config, diff, fetch, init, log, merge (squash), pull, push, rebase, reset, stash, tag

4.5 Summarize best practices and responsible uses of artificial intelligence (AI).

• Common use cases: code generation, regex generation, infrastructure as code generation, documentation, compliance recommendations, security review, code optimization, code linting
• Best practices: avoid copy/paste without review, verify output, data governance (security of data: LLM training, human review; local models: private vs. public), adhere to corporate policy
• Prompt engineering

5.0 Troubleshooting - 26 questions

5.1 Summarize monitoring concepts and configurations in a Linux system.

• Service monitoring: SLA, SLI, SLO
• Data acquisition methods: SNMP (traps, MIBs), agent/agentless, webhooks, health checks, log aggregation
• Configurations: thresholds, alerts, events, notifications, logging

5.2 Given a scenario, analyze and troubleshoot hardware, storage, and Linux OS issues.

• Kernel panic, data corruption, kernel corruption, package dependency issues
• Filesystem will not mount, server not turning on, OS filesystem full, server inaccessible
• Device failure, inode exhaustion, partition not writable, segmentation fault
• GRUB misconfiguration, killed processes, PATH misconfiguration, systemd unit failures
• Missing or disabled drivers, unresponsive process, quota issues, memory leaks

5.3 Given a scenario, analyze and troubleshoot networking issues on a Linux system.

• Misconfigured firewalls, DHCP issues, DNS issues
• Interface misconfiguration: MTU mismatch, bonding, MAC spoofing, subnet, cannot ping server
• Routing issues: gateway, server unreachable, IP conflicts
• Dual stack issues (IPv4 and IPv6), link down, link negotiation issues

5.4 Given a scenario, analyze and troubleshoot security issues on a Linux system.

• SELinux issues: policy, context, booleans
• File and directory permission issues: ACLs, attributes
• Account access, unpatched vulnerable systems, exposed or misconfigured services
• Remote access issues, certificate issues, misconfigured package repository
• Use of obsolete or insecure protocols and ciphers, cipher negotiation issues

5.5 Given a scenario, analyze and troubleshoot performance issues.

• Swapping, out of memory, slow application response, system unresponsiveness
• High CPU usage, high load average, high context switching, high failed log-in attempts
• Slow startup, high I/O wait time, packet drops, jitter, random disconnects
• Random timeouts, high latency, slow response times, high disk latency, low throughput
• Blocked processes, hardware errors, sluggish terminal behavior, exceeding baselines
• Slow remote storage response, CPU bottleneck

System Requirements