Triggering regular tasks with Systemd
Alarm Clock
Systemd can start timers that automatically perform tasks at specified times. The configuration files are known as timer units.
You might want to use your Linux system to automatically create a backup every evening and rotate the log files at regular intervals. In most distributions, time-controlled tasks are handled by the Cron daemon. But Systemd is an interesting alternative to Cron. Systemd controls the startup process of most distributions, and it can also trigger time-controlled and recurring tasks.
Service Providers
The first task is to tell Systemd which task to perform. To do this, you create a configuration file, the Service Unit. Listing 1 shows an example.
A service unit is a text file divided into several sections. The [Service] section is required. ExecStart= is followed by the command to be executed by the system. In Listing 1, Systemd would simply run a script that backs up the system to the /mnt directory. The [Unit] section adds some metadata. In the simplest case, Description= is followed by a description of the task.
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