CompTIA • XK0-006
CompTIA Linux+ (XK0-006) Practice Test
CompTIA Linux+ validates the skills of IT professionals to configure, manage, and troubleshoot Linux systems used in cloud, cybersecurity, and enterprise environments. It covers system administration, scripting, automation, security hardening, and container management.
Exam Details
Questions
699
Duration
90 minutes
Passing Score
720/900
Difficulty
AssociateLast Updated
Mar 2026
Topics Covered
System Configuration and ManagementStorage and Device ManagementNetwork ConfigurationShell Scripting and AutomationSecurity and OS HardeningUser and Account ManagementContainers and VirtualizationSoftware and Package Management
Exam Domain Breakdown
System Management23%
Services and User Management20%
Security18%
Automation, Orchestration, and Scripting17%
Troubleshooting22%
Exam Overview
CompTIA Linux+ (XK0-006) validates the advanced skills of IT professionals to configure, manage, operate, and troubleshoot Linux systems in enterprise, cloud, and cybersecurity environments. This Associate-level certification demonstrates competency across system administration, storage and network configuration, security hardening, shell scripting, containerization, and troubleshooting. The exam emphasizes practical, hands-on knowledge required for modern Linux environments including hybrid cloud deployments, containerized applications, and enterprise security implementations. Successfully obtaining this certification indicates proficiency in automating tasks, implementing security best practices, and managing complex Linux infrastructure at scale.
Who Should Take This Exam
CompTIA Linux+ is designed for IT professionals with foundational Linux experience seeking to advance into system administration, cloud infrastructure, or DevOps roles. Ideal candidates include junior Linux system administrators, junior cloud engineers, junior DevOps engineers, systems engineers, and network engineers managing Linux-based infrastructure. This certification appeals to those with 12 months of hands-on Linux server experience or equivalent knowledge from CompTIA A+, Network+, or Server+ certification. Career paths include Linux systems administrator, cloud infrastructure engineer, cybersecurity operations roles, and site reliability engineer positions.
Prerequisites
Recommended prerequisites include 12 months of hands-on experience managing Linux servers in production or lab environments. While not mandatory, CompTIA strongly recommends foundational IT knowledge equivalent to CompTIA A+, Network+, or Server+ certifications. Candidates should be comfortable with command-line interfaces, basic system administration tasks, file permissions, networking concepts, and troubleshooting methodologies. Linux experience can be gained through home labs, free Linux distributions (Ubuntu, CentOS, Red Hat), or entry-level support roles. A solid understanding of basic networking, storage concepts, and security principles is beneficial.
Exam Format
The CompTIA Linux+ (XK0-006) exam consists of a maximum of 90 scored questions combining multiple-choice and performance-based (hands-on) questions. The exam is delivered online or at testing centers and must be completed within 90 minutes. The scoring scale ranges from 100 to 900, with a passing score of 720 required. Performance-based questions require candidates to demonstrate practical Linux skills in simulated environments. The exam launched July 15, 2025, and is ISO/IEC accredited by ANSI.
Skills Measured
- 1.System Management (23%): Boot processes, kernel modules, device management, storage configuration, package management, virtualization basics, and performance tuning essential for maintaining stable Linux environments
- 2.Services and User Management (20%): User and group account creation and permissions, file access controls, systemd service management, software installation and updates, container fundamentals, and time synchronization
- 3.Security (18%): Authentication mechanisms, SSH configuration, firewall management with iptables/firewalld, OS hardening, password policies, SELinux/AppArmor, cryptography basics, and compliance requirements
- 4.Automation, Orchestration, and Scripting (17%): Shell scripting with bash, basic Python scripting, task scheduling with cron and systemd timers, version control with git, configuration management principles, and responsible automation practices
- 5.Troubleshooting (22%): System monitoring and log analysis, hardware diagnostics, network connectivity troubleshooting, service failure resolution, security incident response, and performance optimization techniques
Study Tips
- Build a hands-on lab environment using free Linux distributions (Ubuntu, CentOS, or Rocky Linux) on virtual machines to practice every command and configuration covered in the five exam domains before test day
- Focus heavily on performance-based questions by practicing simulated Linux administration tasks; the exam includes hands-on questions where you must complete real system administration scenarios in a Linux environment
- Study the five core domains proportionally according to their exam weights: dedicate 23% of study time to System Management, 22% to Troubleshooting, 20% to Services and User Management, 18% to Security, and 17% to Automation
- Use CompTIA's official exam objectives document (available on their website) as your primary study guide; align your preparation materials with these published objectives to ensure comprehensive coverage
- Practice command-line proficiency daily: master essential Linux commands for file management, user administration, process management, networking, and security; performance-based questions heavily emphasize practical CLI skills
Career Benefits
CompTIA Linux+ opens doors to well-compensated roles in high-demand areas of IT. Professionals with this certification earn between $68,000 and $120,000+ annually, with average salaries around $89,000–$91,000 in the United States; experienced professionals in senior roles can exceed six figures. The certification is particularly valuable given the industry shift toward cloud computing and containerization, where Linux expertise is essential. Linux+ validates competency across critical infrastructure technologies, making certified professionals significantly more marketable than non-certified peers. Career advancement opportunities include progression to senior systems administrator, infrastructure architect, cloud engineer, or DevOps engineer roles, with steady salary growth potential as experience accumulates.
Sample Questions
Preview — answers shown5 sample questions with correct answers and explanations. Start a practice session to test yourself across all 699 questions.
1. A systems administrator at Fabrikam Inc. is configuring a new RHEL 9 server for PXE booting to enable automated OS installations across the network. Which two services are minimally required on the PXE server to support this functionality? (Select two!)
Multiple correct answersADHCP server
BNFS server
CTFTP server
DHTTP server
EDNS server
Explanation
PXE (Preboot Execution Environment) booting requires exactly two services at minimum: a DHCP server and a TFTP server. The DHCP server provides the client NIC with an IP address and also informs the client of the TFTP server address and the boot filename to download. The TFTP server then delivers the bootloader (such as pxelinux.0 or grubx64.efi) and the kernel plus initramfs to the booting client. NFS can optionally serve the installation tree for the OS installer but is not required for the PXE boot process itself. HTTP can also optionally serve installation files for Kickstart or Preseed automated installs but is not minimally required. DNS is useful but not required for basic PXE boot functionality.
2. A systems administrator at Fabrikam Inc. has configured a software RAID 5 array using mdadm with three disks. After reviewing /proc/mdstat, the administrator sees the output shows [UU_] for the array. What does this status indicate and what immediate action should be taken? (Select one!)
AOne disk has failed and the array is degraded; add a replacement disk using mdadm --add
BAll disks are operational and the array is in optimal state; no action is required
CThe array is being rebuilt after adding a new disk; wait for the rebuild to complete
DThe array is in read-only mode; run mdadm --readwrite to restore write access
Explanation
In /proc/mdstat output, U represents an active/working disk and _ (underscore) represents a failed or missing disk. The pattern [UU_] for a three-disk RAID 5 array means two disks are active and one has failed, putting the array in a degraded state. RAID 5 can tolerate one disk failure and continue operating, but the array is at risk if another disk fails. The immediate action is to identify the failed disk, replace it physically, and then add it to the array using mdadm --add /dev/md0 /dev/sdX. The array will then rebuild automatically. The [UUU] pattern would indicate all disks are healthy. An underscore always indicates a disk problem, never a rebuild-in-progress state, which would show a rebuild percentage.
3. A developer at Northwind Traders creates a new feature branch and starts working on a bug fix. They create a new source file (feature.py) that has never been added to the repository, plus modify an existing tracked file (main.py). An urgent production issue requires them to immediately switch to the hotfix branch without committing their work. They run 'git stash' and switch branches, but upon returning and running 'git stash pop', they notice feature.py is missing. What is the MOST likely cause of this issue? (Select one!)
AThe git stash pop command only restores the most recent stash, and the stash was overwritten
BBy default, git stash does not include untracked files; feature.py was never staged, so it was not stashed
CThe feature.py file was automatically deleted by git when switching branches because it conflicted with the hotfix branch
DThe git stash command requires the --all flag to include both tracked and untracked modifications
Explanation
By default, git stash only saves changes to files that are already tracked by Git, meaning files that have been previously added to the repository with git add at some point. A brand new file like feature.py that has never been staged is considered untracked, and git stash ignores untracked files unless explicitly told otherwise. The correct approach would have been to either run 'git stash -u' or 'git stash --include-untracked' to include the new file, or to first stage it with 'git add feature.py' before running 'git stash'. Git does not automatically delete untracked files when switching branches, so feature.py would still be in the working directory if the branch switch succeeded, but it would simply not have been captured in the stash. The --all flag (-a) goes even further than --include-untracked by also stashing ignored files, which is rarely the desired behavior and can pull in build artifacts or compiled binaries.
4. A systems administrator at Adatum Corporation needs to use OpenTofu to deploy infrastructure. After writing the configuration files, what is the correct workflow order before applying changes to production? (Select one!)
Atofu plan → tofu init → tofu apply → tofu refresh
Btofu init → tofu apply --dry-run → tofu deploy
Ctofu validate → tofu apply → tofu plan → tofu destroy
Dtofu init → tofu plan → tofu apply
Explanation
The standard OpenTofu workflow begins with tofu init, which initializes the working directory by downloading required provider plugins and setting up the backend. The tofu plan command then creates an execution plan showing what changes will be made without applying them, allowing review before deployment. The tofu apply command then implements the planned changes. This three-step workflow (init → plan → apply) is the standard Infrastructure as Code deployment pattern in both OpenTofu and Terraform. Starting with validate before init would fail because validation requires providers to be initialized. Using apply before plan skips the dry-run review step. There is no tofu deploy command; apply is the command that creates or modifies resources.
5. A systems administrator at Tailspin Toys is troubleshooting why a recently deployed application cannot bind to port 8443 on a RHEL system with SELinux enforcing. The application uses TLS and was previously running on port 443. Which command adds the non-standard port to the correct SELinux port type? (Select one!)
Arestorecon -Rv /etc/httpd
Bsemanage fcontext -a -t http_port_t -p tcp 8443
Csemanage port -a -t http_port_t -p tcp 8443
Dsetsebool -P httpd_can_network_connect 1
Explanation
semanage port -a -t http_port_t -p tcp 8443 permanently adds TCP port 8443 to the http_port_t SELinux port type, allowing HTTP-related services to bind to that port. SELinux controls which ports services can use, and by default only standard ports like 443 are labeled with http_port_t. semanage fcontext is used for file context rules, not port type assignments. setsebool -P httpd_can_network_connect allows the web server to make outbound network connections, which is unrelated to the ability to bind to a specific port. restorecon applies file context rules to the filesystem and has no effect on port type assignments.
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