April 7, 2026

Managing services with systemd

Most modern distributions use systemd to start, stop and supervise background services.

The everyday commands

systemctl status ssh
sudo systemctl restart ssh
sudo systemctl enable --now cron
systemctl list-units --type=service --state=failed

Reading logs

systemd collects the output of every service in the journal. journalctl -u ssh --since today shows today's messages for one unit, and journalctl -f follows everything live.

Writing a unit

A minimal service file lives in /etc/systemd/system/hello.service:

[Unit]
Description=Hello service

[Service]
ExecStart=/usr/local/bin/hello
Restart=on-failure

[Install]
WantedBy=multi-user.target

After creating or editing it, run sudo systemctl daemon-reload.

Timers instead of cron

A .timer unit can replace a cron entry and gives you logging, dependencies and randomised delays for free.

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