An init system has its basic objective to initialize components to be launched after the Linux kernel booting. This system is used to manage services and daemons at all times running in a touring machine.
The init is no longer the top of each process chain and is replaced by the systemd. The systemd is the initialization and management framework for a Linux operating system. systemd activity is structured by “units” that manage start/stop/restart, etc. Run levels are now substituted for objectives.
What is systemd?
Several Linux distributions control system settings and services using systemd.
systemd divides activities into units and unit groups into targets to establish dependencies on other system services and resources.
systemd can automatically boot the devices and targets, or if asked, the server already runs if a user or another systemd target.
What are systemd Unit Files?
In systemd, a unit corresponds to a single component. A text file describing a unit is termed a unit file. It describes what needs to be executed and what runs before and afterward, and other details. The systemd configures and manages system resources such as processes and your system files using unit files. Copy of the unit files in the system is typically stored in the following directory: /lib/systemd/system, which is the default location for the program to install unit files on the system.
What is the systemctl command?
The systemctl command utility interacts with systemd-controlled processes. It can look at and start, stop and change the state of units and objectives in your machine.
Starting and Stopping Services
The start command is used to perform instructions in the service unit file to start a systemd service. You may use sudo if you are a non-root user, as that affects the operating system status.
The command below stops currently running service:
The command below restarts and reloads the service:
Run the enable command to start a service at boot to tell systemd to start services automatically at boot; you must enable them.
The command below is used to disable the service from starting automatically:
The command below is used to check the status of a service on your system:
To conclude, we discussed various techniques of managing our systemd services using the systemctl command in Ubuntu and examining and controlling the systemd system and service manager using various commands. systemctl is a robust, flexible, and easy-to-use command utility that allows us to monitor and interact to build, edit and delete unit files via the Service Manager. The command is used for multiple tasks like enabling, disabling, starting and stopping the services. The above examples reflect the importance of this command in managing our services on our machine.