Which of the following is MOST likely the reason the timer will not start?

A Linux administrator is scheduling a system job that runs a script to check available disk space every hour. The Linux administrator does not want users to be able to start the job.

Given the following:

The Linux administrator attempts to start the timer service but receives the following error message:

Which of the following is MOST likely the reason the timer will not start?
A . The checkdiskspace.timer unit should be enabled via systemct1.
B . The timers.target should be reloaded to get the new configuration.
C . The checkdiskspace.timer should be configured to allow manual starts.
D . The checkdiskspace.timer should be started using the sudo command.

View Answer

Answer: C

Explanation:

The most likely reason the timer will not start is that the checkdiskspace.timer should be configured to allow manual starts. By default, systemd timers do not allow manual activation via systemct1 start, unless they have RefuseManualStart=no in their [Unit] section. This option prevents users from accidentally starting timers that are meant to be controlled by other mechanisms, such as calendar events or dependencies. To enable manual starts for checkdiskspace.timer, the administrator should add RefuseManualStart=no to its [Unit] section and reload systemd.

The other options are not correct reasons for the timer not starting. The checkdiskspace.timer unit does not need to be enabled via systemct1 enable, because enabling a timer only makes it start automatically at boot time or after a system reload, but does not affect manual activation. The timers.target does not need to be reloaded to get the new configuration, because reloading a target only affects units that have a dependency on it, but does not affect manual activation. The checkdiskspace.timer does not need to be started using the sudo command, because the administrator is already running systemct1 as root, as indicated by the # prompt.

Reference: systemd.timer(5) – Linux manual page; systemct1(1) – Linux manual page