XK0-006 Linux Practice Questions
The free XK0-006: CompTIA Linux+ questions that deal with linux, with answers and explanations. The full bank and the timed practice test cover every topic the exam asks about.
Question #3
A Linux administrator tries to install Ansible in a Linux environment. One of the steps is to change the owner and the group of the directory /opt/Ansible and its contents. Which of the following commands will accomplish this task?
Correct answer: B
Explanation
Comprehensive and Detailed Explanation From Exact Extract: The chown command is used to change the owner and group of files and directories. The -R (recursive) flag ensures that all contents within the directory are also updated. The correct syntax is chown -R owner:group directory. So, chown -R Ansible:Ansible /opt/Ansible will change the owner and group for /opt/Ansible and everything inside it to "Ansible". Other options: * A.groupmod is used to modify group properties, not ownership of directories or files. * C.usermod is for modifying user properties or group memberships. * D.chmod changes permissions, not owner/group. [Reference:, CompTIA Linux+ Study Guide: Exam XK0-006, Sybex, Chapter 6: "User and Group Management", Section: "Managing File Ownership and Permissions", CompTIA Linux+ XK0-006 Objectives, Domain 1.0: System Management, ]
Question #4
A Linux administrator receives reports that an application hosted in a system is not completing tasks in the allocated time. The administrator connects to the system and obtains the following details: Which of the following actions can the administrator take to help speed up the jobs?
Correct answer: B
Explanation
This scenario represents a classic CPU-bound performance issue, which is covered under the Troubleshooting domain of CompTIA Linux+ V8. The most important indicator is the load average compared to the number of available CPU cores. The system has 4 CPU cores, as shown by nproc, but the load averages are consistently above 5, with a peak of 7.75. Load average reflects the number of processes either actively running on the CPU or waiting for CPU time. When the load average exceeds the number of CPU cores for extended periods, it indicates CPU contention. Processes must wait longer to be scheduled, resulting in delayed task completion. The memory statistics confirm that memory is not the bottleneck. free -h shows over 3.5 GiB of available memory, and swap usage is minimal. Additionally, vmstat shows no significant swap-in or swap-out activity and low I/O wait, ruling out memory pressure and disk bottlenecks. Increasing swap space would not help because the system is not memory constrained. Adding more disks would not address CPU scheduling delays. Increasing free memory is unnecessary because sufficient memory is already available. Linux+ V8 documentation emphasizes correlating load average with CPU core count to diagnose CPU saturation. The most effective way to speed up job execution in this case is to increase CPU resources, such as adding more vCPUs, moving the workload to a more powerful system, or distributing the workload across multiple systems. Therefore, the correct answer is B. Increase the amount of CPU resources available to the system.
Question #9
A Linux administrator is testing a web application on a laboratory service and needs to temporarily allow DNS and HTTP/HTTPS traffic from the internal network. Which of the following commands will accomplish this task?
Correct answer: C
Explanation
Comprehensive and Detailed Explanation From Exact Extract: The correct way to temporarily allow specific services in a particular zone with firewalld is to use firewall- cmd --add-service=service --zone=zone. Multiple services can be specified in curly braces and separated by commas. The correct syntax is: bash CopyEdit firewall-cmd --add-service={dns,http,https} --zone=internal This command will allow DNS (port 53), HTTP (port 80), and HTTPS (port 443) through the firewall for the "internal" zone temporarily (for the current runtime session). Other options: * A. The command syntax is incorrect; firewalld is a service, not a command-line tool. * B. iptables does not use the --enable-service flag, nor does it have zones in this way. * D. systemctl mask disables services, and the rest of the command is invalid. Reference: CompTIA Linux+ Study Guide: Exam XK0-006, Sybex, Chapter 9: "Networking", Section: "Managing Firewalls with firewalld" CompTIA Linux+ XK0-006 Objectives, Domain 2.0: Networking ===========
Question #10
A Linux administrator wants to add a user to the Docker group without changing the user's primary group. Which of the following commands should the administrator use to complete this task?
Correct answer: C
Explanation
User and group management is a core System Management topic in CompTIA Linux+ V8. When adding a user to an additional group—such as the docker group—care must be taken not to alter the user's primary group. The correct command issudo usermod -aG docker user. The -G option specifies a supplementary group, and the -a (append) option ensures the user is added to the groupwithout removing existing group memberships. This is especially important because omitting -a would overwrite the user's supplementary groups. OptionB, usermod -g docker user, changes the user'sprimary group, which is not desired. OptionsAandDmisuse groupmod, which is intended for modifying group properties, not user membership. Linux+ V8 documentation explicitly warns that failing to use -a with -G can unintentionally remove a user from all other supplementary groups, potentially causing access issues. Therefore, the correct and safe command isC. sudo usermod -aG docker user.
Continue with XK0-006: CompTIA Linux+ Exam
Unlock the full question bank
You have read the first 10 questions. A subscription opens every question in XK0-006: CompTIA Linux+ Exam, the full timed practice test, and your progress and weak-topic reporting.
Single exam
$19.99for 30 days
Full question bank and practice test for one exam, for 30 days.
Single exam
$49.99for 1 year
One exam for a full year. Nothing renews and nothing to cancel.
Full access
$39.99/mo
Every exam in the catalogue, month to month.
Full access
$199.99/yr
Every exam in the catalogue for a year.
Already subscribed? Sign in to pick up where you left off.