A systemd job is running only daily instead of every two hou

A systemd job is running only daily instead of every two hou - CompTIA Linux + XK0-005

Question

A systemd job is running only daily instead of every two hours as intended.
What is MOST likely causing the issue?

Answers

The checkdiskspace.service is not running.
The checkdiskspace.service needs to be enabled.
correct

The OnCalendar schedule is incorrect.
The system-daemon services need to be reloaded.

Explanation

Correct Answer: c. The OnCalendar schedule is incorrect

The most likely reason a systemd job runs daily instead of every two hours is a misconfiguration in the OnCalendar directive within the corresponding timer unit file. This directive defines when the job is triggered. If the syntax specifies a daily schedule instead of every two hours (e.g., daily instead of *-*-* *:00/2), the job will run once a day. Correcting this ensures the timer triggers as intended.

Why the other options are incorrect:

a. The checkdiskspace.service is not running:This service might not be running constantly by design. Timer units in systemd trigger a service to run at specified intervals; the service doesn’t need to run continuously. The issue is about timing, not service execution.
b. The checkdiskspace.service needs to be enabled: Enabling the .service is not required for it to run via a timer. It’s the .timer unit that must be enabled. A disabled service can still be triggered if its associated timer is properly configured and active.
d. The system-daemon services need to be reloaded: Reloading systemd may be useful after changing unit files, but it won’t fix a misconfigured schedule. If OnCalendar is wrong, reloading won’t help — the timer will still follow the incorrect schedule.