CompTIA Linux+
Certification Exam
Objectives
EXAM NUMBER: XK0-005

About the Exam
Candidates are encouraged to use this document help prepare for the CompTIA
Linux+ XK0-005 certification exam. The CompTIA Linux+ certification exam will verify
the successful candidate has the knowledge and skills required configure, manage,
operate, and troubleshoot Linux on-premises and cloud-based server environments,
while using security best practices, scripting, containerization, and automation.
This is equivalent to at least 12 months of hands-on experience working with Linux servers
in a junior Linux support engineer or junior cloud/DevOps support engineer job role.
These content examples are meant to clarify the test objectives and should not be
construed as a comprehensive listing of all the content of this examination.
EXAM ACCREDITATIONThe CompTIA Linux+ exam is accredited by ANSI to show compliance with the ISO 17024
standard and, as such, undergoes regular reviews and updates to the exam objectives.
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CompTIA exams result from subject-matter expert workshops and industry-wide survey
results regarding the skills and knowledge required of an entry-level IT professional.
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PLEASE NOTE
The lists of examples provided in bulleted format are not exhaustive lists. Other
examples of technologies, processes, or tasks pertaining to each objective may
also be included on the exam although not listed or covered in this objectives
document. CompTIA is constantly reviewing the content of our exams and updating
test questions to be sure our exams are current, and the security of the questions isprotected. When necessary, we will publish updated exams based on existing exam
objectives. Please know that all related exam preparation materials will still be valid.

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)

TEST DETAILS
Required exam

XK0-005

Number of questions

Maximum of 90

Types of questions

Multiple-choice and performance-based

Length of test

90 minutes

Recommended experience1 2 months of hands-on experience working withLinux servers, as well as A+, Network+, and Server+
or similar certifications and/or knowledge
720 (on a scale of 100 to 900)

Passing score		
EXAM OBJECTIVES (DOMAINS)

The table below lists the domains measured by this examinationand the extent to which they are represented.
DOMAIN 		PERCENTAGE OF EXAMINATION

1.0 System Management 		
2.0 Security 		
3.0 Scripting, Containers, and Automation
4.0 Troubleshooting 		
Total 		

32%
21%
19%
28%
100%

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)

1.0 System Management
1.1

Summarize Linux fundamentals.
• Filesystem Hierarchy
Standard (FHS)- /boot- /proc- /sys- /var- /usr- /lib- /dev- /etc- /opt- /bin- /sbin- /home- /media- /mnt- /root- /tmp• Basic boot process- Basic input/output system (BIOS)- Unified Extensible Firmware
Interface (UEFI)- Commands• mkinitrd• grub2-install• grub2-mkconfig• grub2-update• dracut- initrd.img- vmlinuz- Grand Unified Bootloader
version 2 (GRUB2)- Boot sources• Preboot eXecution
Environment (PXE)• Booting from Universal
Serial Bus (USB)• Booting from ISO• Kernel panic• Device types in /dev
- Block devices- Character devices- Special character devices• /dev/null• /dev/zero• /dev/urandom

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)

• Basic package compilationfrom source- ./configure- make- make install• Storage concepts- File storage- Block storage- Object storage- Partition typo
• Master boot record (MBR)• GUID [globally unique identifier]Partition Table (GPT)- Filesystem in Userspace (FUSE)- Redundant Array of
Independent (or Inexpensive)
Disks (RAID) levels• Striping• Mirroring• Parity• Listing hardware information- lspci- lsusb- dmidecode1.0 | System Management

1.2

Given a scenario, manage files and directories.
• File editing
- sed
- awk
- printf- nano- vi(m)• File compression,archiving, and backup- gzip- bzip2
- zip
- tar
- xz
- cpio- dd

1.3• File metadata- stat- file• Soft and hard links• Copying files between systems- rsync- scp- nc• File and directory operations
- mv
- cp
- mkdir- rmdir
- ls
- pwd
- rm
- cd
-.
- ..
-~
- tree- cat- touchGiven a scenario, configure and manage
storage using the appropriate tools.
• Disk partitioning- Commands• fdisk• parted• partprobe• Mounting local and remote devices- systemd.mount- /etc/fstab- mount- Linux Unified Key Setup (LUKS)- External devices• Filesystem management- XFS tools- Ext4 tools- Btrfs tools• Monitoring storage spaceand disk usage
- df
- du
• Creating and modifying
volumes using Logical
Volume Manager (LVM)- Commands
• pvs
• vgs
• lvs
• lvchange• lvcreate• vgcreate• lvresize• pvcreate• vgextend

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)• Inspecting RAID implementations- mdadm- /proc/mdstat• Storage area network (SAN)/
network-attached storage (NAS)- multipathd- Network filesystems• Network File System (NFS)• Server Message Block(SMB)/Common Internet
File System (CIFS)• Storage hardware- lsscsi- lsblk- blkid- fcstat1.0 | System Management

1.4

Given a scenario, configure and use theappropriate processes and services.
• System services- systemctl• stop• start• restart• status• enable• disable• mask• Scheduling services- cron- crontab
- at

1.5

• Process management- Kill signals• SIGTERM• SIGKILL• SIGHUP- Listing processes and open files
• top
• ps
• lsof• htop- Setting priorities• nice• renice- Process states• Zombie• Sleeping• Running• Stopped- Job control
• bg
• fg
• jobs• Ctrl+Z• Ctrl+C• Ctrl+D- pgrep- pkill- pidof

Given a scenario, use the appropriate
networking tools or configuration files.
• Interface management- iproute2 tools
• ip
• ss
- NetworkManager• nmcli- net-tools• ifconfig• ifcfg• hostname• arp• route- /etc/sysconfig/network-scripts/• Name resolution- nsswitch- /etc/resolv.conf- systemd• hostnamectl• resolvectl- Bind-utils• dig• nslookup• host- WHOIS

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)• Network monitoring- tcpdump- wireshark/tshark- netstat- traceroute- ping- mtr• Remote networking tools- Secure Shell (SSH)- cURL- wget- nc- rsync- Secure Copy Protocol (SCP)- SSH File Transfer Protocol (SFTP)

1.0 | System Management

1.6

Given a scenario, build and install software.
• Package management
- DNF
- YUM
- APT
- RPM
- dpkg- ZYpp1.7• Sandboxed applications- snapd- Flatpak- AppImage• System updates- Kernel updates- Package updates

Given a scenario, manage software configurations.
• Updating configuration files- Procedures• Restart service• Reload service- .rpmnew- .rpmsave
Repository configuration files• /etc/apt.conf• /etc/yum.conf• /etc/dnf/dnf.conf• /etc/yum.repo.d• /etc/apt/sources.list.d• Configure kernel options- Parameters• sysctl• /etc/sysctl.conf- Modules• lsmod• imsmod• rmmod• insmod• modprobe• modinfo

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)• Configure common system services- SSH- Network Time Protocol (NTP)- Syslog- chrony• Localization- timedatectl- localectl

2.0 Security
2.1

Summarize the purpose and use of security
best practices in a Linux environment.
• Managing public key
infrastructure (PKI) certificates- Public key- Private key- Self-signed certificate- Digital signature- Wildcard certificate- Hashing- Certificate authorities

2.2• Certificate use cases-S ecure Sockets Layer (SSL)/
Transport Layer Security (TLS)- Certificate authentication- Encryption• Authentication- Tokens- Multifactor authentication (MFA)-P
 luggable authentication
modules (PAM)-S
 ystem Security Services
Daemon (SSSD)-L ightweight Directory
Access Protocol (LDAP)- Single sign-on (SSO)• Linux hardening- Security scanning- Secure boot• UEFI- System logging configurations- Setting default umask- Disabling/removing
insecure services- Enforcing password strength- Removing unused packages- Tuning kernel parameters- Securing service accounts- Configuring the host firewall

Given a scenario, implement identity management.
• Account creation and deletion- Utilities• useradd• groupadd• userdel• groupdel• usermod• groupmod
• id
• who
•w
- Default shell- Configuration files• /etc/passwd• /etc/group• /etc/shadow• /etc/profile• /etc/skel• .bash_profile• .bashrc• Account management- passwd- chage- pam_tally2- faillock- /etc/login.defs

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)

2.0 | Security

2.3

Given a scenario, implement and configure firewalls.
• Firewall use cases- Open and close ports- Check current configuration- Enable/disable Internet
protocol (IP) forwarding

2.4

Key firewall features- Zones- Services- Stateful- StatelessGiven a scenario, configure and execute remoteconnectivity for system management.
• SSH- Configuration files• /etc/ssh/sshd_config• /etc/ssh/ssh_config• ~/.ssh/known_hosts• ~/.ssh/authorized_keys• /etc/ssh/sshd_config• /etc/ssh/ssh_config• ~/.ssh/config- Commands• ssh-keygen• ssh-copy-id• ssh-add- Tunneling• X11 forwarding• Port forwarding• Dynamic forwarding

2.5• Common firewall technologies- firewalld- iptables- nftables- Uncomplicated firewall (UFW)• Executing commands
as another user
- /etc/sudoers- PolicyKit rules- Commands• sudo• visudo• su –• pkexec

Given a scenario, apply the appropriate access controls.
• File permissions- Access control list (ACL)- Set user ID (SUID)- Set group ID (SGID)- Sticky bit• Security-enhanced Linux (SELinux)- Context permissions- Labels• Autorelabel- System booleans- States• Enforcing• Permissive• Disabled- Policy types• Targeted• Minimum• AppArmor- Application permissions• Command-line utilities- chown- umask- chmod- getfacl- setfacl- ls- setenforce- getenforce- chattr- lsattr- chgrp- setsebool- getsebool- chcon- restorecon- semanage- audit2allow

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)

3.0 Scripting, Containers,and Automation
3.1

Given a scenario, create simple shell scripts
to automate common tasks.
• Shell script elements- Loops• while• for• until- Conditionals• if• switch/case- Shell parameter expansion• Globbing• Brace expansions- Comparisons• Arithmetic• String• Boolean- Variables- Search and replace- Regular expressions

3.2- Standard stream redirection
•|
• ||
•>
• >>
•<
• <<
•&
• &&
• Redirecting•
stderr•stdout- Here documents- Exit codes- Shell built-in commands• read• echo• source• Common script utilities
• awk
• sed
• find• xargs• grep• egrep
• tee
• wc
• cut
• tr
- head- tail• Environment variables- $PATH- $SHELL- $?
• Relative and absolute paths

Given a scenario, perform basic container operations.
• Container management- Starting/stopping- Inspecting- Listing- Deploying existing images- Connecting to containers- Logging- Exposing ports• Container image operations- build- push- pull- list- rmi

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)

3.0 | Scripting, Containers, and Automation

3.3

Given a scenario, perform basic version control using Git.
• clone• push• pull• commit• add• checkout• branch• tag• gitignore

3.4

Summarize common infrastructure as code technologies.
• File formats- YAML Ain’t Markup
Language (YAML)- JavaScript Object
Notation (JSON)• Utilities- Ansible- Puppet- Chef- SaltStack- Terraform3.5• Continuous integration/
continuous deployment (CI/CD)- Use cases• Advanced Git topics- merge- rebase- Pull requests

Summarize container, cloud, and orchestration concepts.
• Kubernetes benefits andapplication use cases- Pods- Sidecars- Ambassador containers• Single-node, multicontainer
use cases- Compose• Container persistent storage• Container networks- Overlay networks- Bridging- Network address translation (NAT)- Host• Service mesh• Bootstrapping- Cloud-init• Container registries

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)

4.0 Troubleshooting
4.1

Given a scenario, analyze and troubleshoot storage issues.
• High latency- Input/output (I/O) wait
• Low throughput• Input/output operations per
second (IOPS) scenarios- Low IOPS

4.2

• Device issues- Non-volatile memory
express (NVMe)- Solid-state drive (SSD)- SSD trim
- RAID- LVM- I/O errors• Mount option problems

Given a scenario, analyze and troubleshootnetwork resource issues.
• Network configuration issues- Subnet- Routing• Firewall issues• Interface errors- Dropped packets- Collisions- Link status

4.3• Capacity issues- Low disk space- Inode exhaustion• Filesystem issues- Corruption- Mismatch• I/O scheduler• Bandwidth limitations- High latency• Name resolution issues- Domain Name System (DNS)• Testing remote systems- Nmap- openssl s_client

Given a scenario, analyze and troubleshoot central
processing unit (CPU) and memory issues.
• Runaway processes• Zombie processes• High CPU utilization• High load average• High run queues• CPU times- steal- user- system- idle- iowait• CPU process priorities- nice- renice• Memory exhaustion- Free memory vs. file cache• Out of memory (OOM)- Memory leaks- Process killer• Swapping

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)• Hardware- lscpu- lsmem- /proc/cpuinfo- /proc/meminfo

4.0 | Troubleshooting

4.4

Given a scenario, analyze and troubleshootuser access and file permissions.
• User login issues• User file access issues- Group- Context- Permission- ACL- Attribute- Policy/non-policy

4.5• Password issues• Privilege elevation• Quota issues

Given a scenario, use systemd to diagnose andresolve common problems with a Linux system.
• Unit files- Service• Networking services• ExecStart/ExecStop• Before/after• Type• User• Requires/wants- Timer• OnCalendar• OnBootSec• Unit• Time expressions- Mount• Naming conventions• What• Where• Type• Options- Target• Default• Multiuser• Network-online• Graphical• Common problems- Name resolution failure- Application crash- Time-zone configuration- Boot issues- Journal issues- Services not starting on time

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)

Linux+ Acronym List
The following is a list of acronyms that appear on the CompTIA
Linux+ XK0-005 exam. Candidates are encouraged to review
the complete list and attain a working knowledge of all listed
acronyms as part of a comprehensive exam preparation program.
ACRONYM

SPELLED OUT

ACLAccess Control List
BIOS
Basic Input/Output System
CI/CD	Continuous Integration/
Continuous Deployment
CIFS
Common Internet File System
CPU
Central Processing Unit
DNS
Domain Name System
FHS
Filesystem Hierarchy Standard
FUSE
Filesystem in Userspace
GPT	GUID (Globally Unique
Identifier) Partition Table
GRUB
Grand Unified Bootloader
GUID
Globally Unique Identifier
I/O
Input/Output
IOPS
Input/Ouput Operations Per Second
IPInternet ProtocolISO	International Organizationfor Standardization
JSON
JavaScript Object Notation
LDAP
Lightweight Directory Access Protocol
LUKS
Linux Unified Key Setup
LVM
Logical Volume Manager
MFA
Multifactor Authentication
MBR
Master Boot Record
NAS
Network-attached Storage
NAT
Network Address Translation
NFS
Network File System
NTP
Network Time Protocol

ACRONYM

SPELLED OUT

NVMe
Non-volatile Memory Express
OOM
Out of Memory
PAM
Pluggable Authentication Module
PKI
Public Key Infrastructure
PXE
Preboot Execution Environment
RAID	Redundant Array of Independent(or Inexpensive) Disks
SAN
Storage Area Network
SCP
Secure Copy Protocol
SELinux
Security Enhanced LinuxSFTP
Secure File Transfer Protocol
SGID
Set Group ID
SMB
Server Message Block
SSD
Solid-state Drive
SSH
Secure Shell
SSL
Secure Sockets Layer
SSO
Single Sign-On
SSSD
System Security Services Daemon
SUID
Set User ID
TLS
Transport Layer Security
UEFI
Unified Extensible Firmware Interface
UFW
Uncomplicated Firewall
USB
Universal Serial BusYAMLYAML Ain’t Markup Language

CompTIA Linux+ Certification Exam Objectives 1.0 (Exam Number: XK0-005)

Linux+ Proposed Hardware and Software List
CompTIA has included this sample list of hardware and software toassist candidates as they prepare for the Linux+ XK0-005 exam.
This list may also be helpful for training companies that wish to
create a lab component for their training offerings. The bulleted
lists below each topic are sample lists and are not exhaustive.
EQUIPMENTSOFTWARE• Laptop or desktop that supports virtualizationor access to a cloud service provider• Network- Router- Switch- Wireless access point• Internet access• Repository access• PuTTY or SSH client• Automation tools (e.g., Ansible, Puppet, etc.)• Git• Virtualization software• Docker or Podman
RECOMMENDED DISTRIBUTIONSSPARE PARTS/HARDWARE• Hard disk drive• USB or DVD media• Ubuntu• Fedora Linux• Debian• openSUSE• Red Hat Enterprise Linux© 2021 CompTIA, Inc., used under license by CompTIA, Inc. All rights reserved. All certification programs and education related to suchprograms are operated exclusively by CompTIA, Inc. CompTIA is a registered trademark of CompTIA, Inc. in the U.S. and internationally.
Other brands and company names mentioned herein may be trademarks or service marks of CompTIA, Inc. or of their respective owners.
Reproduction or dissemination prohibited without the written consent of CompTIA, Inc. Printed in the U.S. 08301-May21