Reinforce XK0-006 concepts with active-recall study cards covering all 5 blueprint domains. Each card shows the question on the front and the correct answer with a full explanation on the back.
Flashcards work through active recall — the process of retrieving information from memory rather than passively re-reading it. Research consistently shows that active recall produces stronger, longer-lasting memory than re-reading study guides. For XK0-006 preparation, this means flashcards are one of the highest-return study tools available.
Attempt recall first
Read the XK0-006 question on each card, pause, and attempt to formulate the answer in your own words before revealing. This retrieval attempt — even if wrong — dramatically strengthens memory compared to immediately reading the answer.
Review wrong cards again
When you get a card wrong, note it and add it back to your review pile. Spaced repetition — seeing difficult cards more frequently — is the mechanism that makes flashcard study far more efficient than linear reading.
Study by domain
Group your XK0-006 flashcard sessions by domain for the first 3–4 weeks. Master one domain before moving to the next. In the final week, shuffle all cards together to test cross-domain recall — which is what the real XK0-006 exam requires.
Short sessions beat marathon reviews
20–30 flashcard cards per session, done daily, produces better retention than a single 200-card marathon session. Five short daily sessions per week over 4 weeks gives you over 400 total card reviews — enough to reliably pass XK0-006.
Sample cards from the XK0-006 flashcard bank. Read the question, think of the answer, then read the explanation below.
A Linux administrator needs to ensure that a new service, myapp.service, starts automatically at boot and is currently running. The administrator runs 'systemctl enable --now myapp.service' and receives no errors, but after a reboot the service is not running. Which of the following is the most likely cause?
The service unit file is missing the [Install] section with WantedBy=multi-user.target.
The [Install] section defines how a unit integrates with systemd's boot targets. WantedBy=multi-user.target is what allows enable to create the symlink that pulls the service into the boot transaction. Without it, enable --now starts the unit but does not configure it for automatic startup, so after reboot the service remains inactive.
A Linux administrator is troubleshooting a service that fails to start. The service unit file contains 'User=appuser' and 'Group=appgroup'. The administrator runs 'systemctl start app.service' and sees the error 'Failed to determine user credentials: No such process'. Which of the following is the most likely cause?
The user appuser does not exist on the system.
systemd resolves User= and Group= before launching the process. If the specified account cannot be found in the user database, systemd aborts with a credential resolution error. The fix is to create the missing user or correct the unit file to reference an existing account, then reload systemd and restart the service.
A Linux administrator needs to configure a system so that the service `httpd` starts automatically when the system boots into the default target. Which command should the administrator use?
systemctl enable httpd
Enabling a service with `systemctl enable httpd` sets up the proper symlinks so that systemd starts the service when the default target is reached during boot. Starting the service only affects the current runtime, while enabling ensures persistence across reboots. Other commands like `chkconfig` are for older init systems and `daemon-reload` only refreshes unit definitions.
A Linux administrator wants to ensure a bash script stops execution immediately if any command fails. Which line should be added to the script?
set -e
`set -e` instructs bash to exit immediately if any command returns a non-zero exit status, which is exactly the fail-fast behavior the administrator wants. This prevents subsequent commands from running after a failure, avoiding cascading errors in scripts. It is the standard idiom for making bash scripts robust in automation and CI environments.
A developer is writing a Dockerfile. The application requires a configuration file that should be copied from the build context and the container should expose port 8080. Which combination of Dockerfile instructions is correct?
COPY config.txt /app/ and EXPOSE 8080
COPY adds files from the build context, and EXPOSE documents the port. Other instructions serve different purposes.
A team uses Ansible for configuration management. They want to ensure a service is running on all managed nodes. Which Ansible module should be used in the playbook?
service
The Ansible service module is the generic, cross-platform module for managing services (started, stopped, enabled, restarted) and works across systemd, SysVinit, Upstart, and other init systems. It is the correct choice when the playbook must ensure a service is running on all managed nodes regardless of the underlying init system. Using service with state: started and enabled: yes is the idiomatic way to guarantee a service is running and persists across reboots.
A Linux administrator needs to locate all files in the /var directory that have been modified within the last 30 minutes and are larger than 10MB. Which command accomplishes this task?
find /var -mmin -30 -size +10M
The correct command is `find /var -mmin -30 -size +10M`. The `-mmin -30` option tells find to match files modified less than 30 minutes ago (the minus sign means 'less than'), and `-size +10M` matches files larger than 10 megabytes. This combination precisely meets the requirement of files modified within the last 30 minutes and larger than 10MB.
An administrator wants to grant a specific user, 'jdoe', read and write access to a file that is owned by root:root with permissions 640. The administrator does not want to change the file's owner or group. Which approach should be used?
Use setfacl -m u:jdoe:rw file
POSIX ACLs allow granting permissions to specific users or groups without altering the file's owner or group. The command 'setfacl -m u:jdoe:rw file' adds an ACL entry giving jdoe read and write access while leaving root:root ownership and the 640 mode intact. This is the standard, least-disruptive approach for per-user access on a shared file.
A user needs to view the first 15 lines of a large log file. Which command is most appropriate?
head -n 15 filename
The command 'head -n 15 filename' is the most appropriate and efficient way to view the first 15 lines of a file. The head command is designed for this purpose, and the -n option specifies the number of lines. This is a standard Linux command and is more direct than piping cat to head.
A Linux administrator wants to search for all occurrences of the word 'ERROR' in log files under /var/log, ignoring case, and also print the line numbers. Which command should be used?
grep -rin 'ERROR' /var/log
The command 'grep -rin ERROR /var/log' combines -r (recursive search through directories), -i (case-insensitive match), and -n (print line numbers). This searches every file under /var/log for 'ERROR' regardless of case and prefixes each match with its line number, exactly matching the requirement.
A Linux administrator needs to add a new user named 'jdoe' with a home directory and a bash shell. Which command accomplishes this?
useradd -m -s /bin/bash jdoe
The useradd command with -m creates the home directory and -s /bin/bash sets the login shell, so 'useradd -m -s /bin/bash jdoe' creates user jdoe with a home directory and bash shell in one step. This is the canonical low-level command on RHEL/CentOS and other systemd-based distributions for non-interactive user creation.
A security audit reveals that users can change their password without meeting complexity requirements. Which PAM module should be configured to enforce password complexity?
pam_pwquality
pam_pwquality is the PAM module that enforces password complexity requirements such as minimum length, character classes, and dictionary checks on Linux. It replaced the older pam_cracklib module and is configured in /etc/security/pwquality.conf and referenced in /etc/pam.d/system-auth or /etc/pam.d/common-password. Configuring it ensures users cannot set weak passwords that violate policy.
An administrator wants to allow the user 'ops' to run only the command '/usr/bin/systemctl restart httpd' via sudo on a specific host 'webserver'. Which /etc/sudoers entry is correct?
ops webserver=(root) /usr/bin/systemctl restart httpd
The sudoers entry format is: user host=(runas) command. To allow user 'ops' to run only the specified command on host 'webserver' as root, the correct entry is 'ops webserver=(root) /usr/bin/systemctl restart httpd'. This restricts both the host and the command, and specifies the runas user as root.
A Linux administrator needs to check which services are listening on TCP ports on a server. Which command should be used to replace the deprecated netstat command?
ss -tlnp
The `ss` command is the modern replacement for `netstat`, providing socket statistics. The flags `-tlnp` specifically show TCP (`-t`) listening (`-l`) sockets with numeric ports (`-n`) and the process (`-p`) using them, which directly answers the administrator's need to see listening TCP ports and associated services.
A user reports that they cannot reach a website. The administrator wants to check the path that packets take to the destination server. Which command should be used?
traceroute
The `traceroute` command is used to trace the path packets take from the source to a destination host, showing each hop (router) along the way. It uses ICMP echo requests (or UDP packets on Linux) with incrementing TTL values to elicit ICMP Time Exceeded messages from intermediate routers, which reveals the network path. This directly addresses the administrator's need to check the path to the destination server.
A Linux engineer is investigating high disk I/O on a server. Which command provides disk I/O statistics including %util, await, r/s, and w/s?
iostat -x 1
iostat reports CPU and disk I/O statistics, with columns like %util, await, r/s, and w/s.
The XK0-006 flashcard bank covers all 5 official blueprint domains published by CompTIA. Cards are distributed proportionally, so domains with higher exam weight have more cards.
Domain Coverage
Services and User Management
Automation, Orchestration, and Scripting
System Management
Security
Troubleshooting
Both flashcards and practice questions are evidence-based study tools. The difference is in what they train:
Flashcards — concept retention
Best for memorising definitions, acronyms, protocol behaviours, command syntax, and conceptual distinctions. Use flashcards to build the foundational vocabulary that XK0-006 questions assume you know.
Best in: weeks 1–3
Practice tests — application
Best for applying concepts to realistic scenarios, eliminating distractors, and building exam stamina.XK0-006 questions test scenario reasoning — not just recall — so practice tests are essential.
Best in: weeks 3–6
The most effective XK0-006 study plan combines both: use flashcards for the first 2–3 weeks to build conceptual foundations, then shift to practice tests and mock exams in the final 2–3 weeks to apply and benchmark that knowledge. Most candidates who pass on their first attempt use both tools.
Yes. Courseiva provides free XK0-006 flashcards across all official exam domains. Every card includes the correct answer and a full explanation of why it is right and why the distractors are wrong. The platform also includes topic-based practice, mock exams, and readiness tracking — no account required.
Courseiva has 781+ original XK0-006 flashcards across all 5 exam blueprint domains. New cards are added regularly as the question bank grows. All cards are checked against the official CompTIA exam objectives, with editorial oversight from an experienced network and security engineer.
Courseiva flashcards are purpose-built for IT certification exams. Unlike generic flashcard platforms where content quality varies, every Courseiva card is mapped to the official XK0-006 exam blueprint, written by engineers who hold the certification, and includes a full explanation of the correct answer and why the distractors are wrong. This explanation quality is what separates genuine learning from rote memorisation.
Courseiva is a web platform — an internet connection is required. For offline study, we recommend creating free Courseiva account, using the platform in your browser, and using your device's offline capabilities if your browser supports offline web apps.
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