whatis systemd
systemd
The init system and service manager used by most Linux distributions, controlling boot, services, logging, timers, and more.
What Is systemd in Linux?
systemd runs as PID 1 and starts everything else from declarative unit files. It starts services in parallel based on dependencies, restarts them when they crash, and tracks every process each service spawns using cgroups.
The wider project includes journald for logging, networkd and resolved for networking, logind for sessions, and timers as a cron replacement. systemctl is the main command for managing it.
Example
systemctl status
systemctl list-units --failedLearn more about systemd
- What Is systemd? systemd is the init system and service manager used by most major Linux distributions. Understanding what it does, how it is structured, and why it replaced older init systems explains a lot about how modern Linux works.
- Managing Services with systemctl systemctl is the command-line interface to systemd. This guide covers starting, stopping, enabling, inspecting, and troubleshooting services, along with the most useful systemctl commands for daily system administration.
- Writing systemd Service Files Explained Beyond using systemctl to manage existing services, writing your own .service unit file lets you run any script or program as a properly managed systemd service. This guide covers unit file structure, common directives, and enabling a custom service.
Related tools
- systemd Unit Builder Generate systemd service files with restart policies, dependencies, and sandboxing options.