systemd-logind.service

systemctl [OPTIONS] COMMAND systemd-logind.service

start
    Starts the systemd-logind.service.

stop
    Stops the systemd-logind.service. Use with caution as it will disrupt user sessions.

restart
    Restarts the systemd-logind.service.

status
    Displays the current status of the systemd-logind.service, including its activity and recent logs.

enable
    Enables the systemd-logind.service to start automatically at boot.

disable
    Disables the systemd-logind.service from starting automatically at boot.

reload
    Reloads the systemd-logind.service configuration (if applicable without restarting the service).

mask
    Masks the systemd-logind.service, preventing it from being started manually or by other services.

unmask
    Unmasks the systemd-logind.service, allowing it to be started again.

The systemd-logind.service is a core systemd service responsible for managing user logins, sessions, and seat devices. It acts as an intermediary between the kernel's TTY and input layer and higher-level userland components like desktop environments and display managers.

Its primary functions include tracking logged-in users and their active sessions, managing multi-seat environments, and providing mechanisms for session control such as screen locking, suspend, and hibernate actions. It integrates deeply with the system's power management features, allowing for graceful shutdown, reboot, or suspend/hibernate operations initiated by users or other system components. Through its D-Bus interface, logind exposes critical functionality that enables various applications and services to interact with user sessions and system power states, making it an indispensable part of modern Linux desktop and server environments.

systemd-logind.service is a critical component for most modern Linux desktop environments. Stopping or restarting this service can severely disrupt active user sessions, leading to logout, frozen applications, or system instability. It is generally not recommended to manually stop this service unless you understand the full implications and are prepared for potential session termination.

systemd-logind exposes a comprehensive D-Bus API, which is the primary method for other system components (like display managers, desktop environments, and power managers) to query and manipulate user sessions, seat assignments, and power management states. This allows for a standardized and robust inter-process communication.

logind manages 'seats', which are logical groupings of input and output devices (e.g., keyboard, mouse, monitor) associated with a physical user. This is crucial for environments with multiple users simultaneously logged in on different sets of hardware, such as multi-seat systems or virtual consoles.

systemd-logind was introduced as part of the systemd project, which began development around 2010 with the goal of replacing the traditional SysVinit and Upstart init systems. It emerged from the need for a more centralized and robust session and login management system in Linux. Its integration with systemd brought a unified approach to user session tracking and power management that was previously fragmented across various display managers and utilities, solidifying its role as a fundamental component in many contemporary Linux distributions.

systemd(1), systemctl(1), loginctl(1), pam(8), udev(7)