linux plus practice test Practice Exam 2025: Latest Questions

An administrator needs to ensure a web service starts automatically at boot and can be checked quickly for its current running state. Which approach is BEST on a system using systemd?

A user reports they cannot create files in /shared, but they can read existing files. The directory is owned by root:devteam and has permissions drwxrwxr-x. The user is in the devteam group. What is the MOST likely cause?

Which command is BEST to show current disk usage for each mounted filesystem in a human-readable format?

A security policy requires that SSH logins must not allow password authentication and must use key-based authentication only. Which configuration change meets this requirement?

A scheduled maintenance script must run every day at 01:30 and should execute even if the system was powered off at that time (it should run shortly after boot). Which is the BEST solution?

A developer needs a container to reach a database running on the Linux host using a stable, supported method without exposing the database to the entire network. Which is the BEST approach?

A server intermittently fails to resolve DNS names. The administrator suspects the resolver configuration is being overwritten by a network management service. Which file is MOST commonly managed and rewritten dynamically on many Linux systems?

An administrator needs to safely test changes to a service unit without restarting the entire systemd daemon, and then apply those changes. Which command sequence is BEST?

A company requires that developers can run a maintenance command as root, but ONLY that command, and they must not be able to start a root shell. Which configuration is BEST?

After expanding a VM disk, an administrator extends an LVM logical volume and then runs resize2fs, but the filesystem size does not change. The logical volume is formatted with XFS. Which action should the administrator take instead?

A Linux host has a directory where multiple users collaborate. The administrator must ensure that any new files created in the directory inherit the directory's group ownership automatically. Which action best meets this requirement?

An administrator needs a quick way to check whether the SSH daemon is currently enabled to start at boot on a system using systemd. Which command is most appropriate?

A user reports they can read a file but cannot modify it. The file permissions are: -rw-r--r-- 1 alice dev 1200 ... report.txt. The user is alice. What is the MOST likely reason?

A server requires that all outbound web traffic from automation scripts use a corporate HTTP proxy, but administrators do not want to hardcode proxy settings into each script. Which approach is the BEST practice?

After updating a system, a service fails to start. The unit shows: "Failed to start..." and the administrator needs to see the detailed logs for only the last boot for that unit. Which command should they use?

A security policy requires that administrators log in with SSH keys, but also provide a one-time code (TOTP) for interactive SSH sessions. Which SSH configuration change best supports this requirement?

A developer needs to run a one-off command inside a container and automatically remove the container afterward to avoid cluttering the host. Which container run option best meets this requirement?

A system with SELinux enforcing is hosting a custom web app on TCP port 8081. The service is running, but connections are refused only when SELinux is enforcing. Which action is the BEST next step to allow the service while maintaining SELinux protections?

An administrator must ensure that only a specific administrative group can run a set of privileged commands, and each invocation must be logged with the original username. Which solution is MOST appropriate?

A Linux system intermittently becomes unreachable over the network during peak load. Locally, CPU and memory look normal, but users report high latency and timeouts. The administrator suspects packet drops due to receive queue saturation. Which command is BEST to confirm interface-level RX drops and errors?

A junior administrator wants to temporarily stop a service from starting during boot for troubleshooting but does not want to prevent it from being started manually later. Which systemd action should they use?

A Linux host should allow SSH connections only from 192.0.2.0/24. The administrator wants a host-based access control method that applies even if a firewall rule is accidentally removed. Which approach best meets this requirement?

A containerized web app cannot write to /var/log/app inside the container. The directory is bind-mounted from the host and is owned by root:root on the host. The container runs as a non-root user. SELinux is enforcing. Which is the BEST next step to allow writes while maintaining SELinux protections?

A system shows 'No space left on device' when creating new files, but df -h shows 40% free space on the filesystem. Which command is MOST likely to identify the underlying cause?

An administrator needs a scheduled task to run at 02:15 every day, but ONLY if the system is on AC power. The administrator wants a solution that integrates cleanly with systemd. Which solution is BEST?