Yksikötiedostot

Yksikötiedostot is a Finnish term that translates to "unit files" in English. This concept is primarily used in the context of system and service management, most notably within the Linux operating system using systemd. A unit file is a configuration file that describes a set of resources, processes, or other system components that systemd can manage.

These files define how systemd should start, stop, restart, and monitor specific units. Units can represent a wide variety of things, including services (like a web server), sockets (for network communication), devices, mount points, timers, and more. Each unit file typically resides in specific directories within the system's file system, with common locations including /etc/systemd/system/ for system-wide configurations and /usr/lib/systemd/system/ for distribution-provided units.

The structure of a unit file is organized into sections, each denoted by square brackets, such as [Unit], [Service], [Socket], or [Install]. The [Unit] section usually contains metadata about the unit, including its description and dependencies. The [Service] section, relevant for process-based units, defines how the service should be executed, including commands to run and user privileges. Other sections configure specific unit types.

By using unit files, systemd provides a standardized and declarative way to manage system resources and services, improving system reliability and manageability. Administrators can create, modify, and analyze these files to control system behavior and troubleshoot issues.