What are daemons?

[wisly.k Member Find all posts View Profile Close wisly.k]

Hello everyone,

Please explain what are daemons in Linux and why it is important?

[zayn_william Member Find all posts View Profile Close zayn_william]

The term "daemon" (pronounced "dee-muhn") refers to a Linux term for a computer program that runs in the background to do tasks that the default Operating System might not be able to perform. Typically, daemons are employed to manage services in the background without having direct access to interactive users. Daemons are designed to manage repeated requests and pass them on to the proper programs for execution.

Working:

They start operating shortly as the system boots up and keep running continually in the background. Daemons start-up independently of user sessions by distancing themselves from the terminal that controls them. They offer services including printing, database administration, network access, web hosting, and more. Daemons continuously watch for events or requests, including incoming network connections or scheduled tasks, and act in response. They effectively manage system resources, gently handle errors, and frequently offer parameters that may be changed to customize their behavior. Since they carry out activities without direct user contact and guarantee the availability of essential services, daemons are essential to the dependable and ongoing running of Linux systems.

List of daemon services

1. sshd: The Secure Shell daemon, or sshd, enables safe remote account access and network command execution.
2. httpd: The HTTP server daemon, such as Apache HTTP Server, offers web hosting services, managing HTTP requests as well as providing online content.
3. cupsd: The Common Linux Printing System daemon, or cupsd, controls printing features such as print job queues and printer settings.
4. mysqld: Applications can store, retrieve, and alter data using the MySQL database system with the help of the database administration services that the MySQL daemon offers.
5. named: Domain name resolution in the Domain Name System (DNS) is carried out by the BIND daemon. It converts IP addresses to domain names and the other way around.
6. cron: The cron daemon permits the automated execution of tasks or instructions at certain intervals or periods once they have been scheduled. It is frequently used to automate routine processes, backups, and system maintenance chores.
7. syslogd: System log messages produced by various processes and services are gathered and processed by the system logging daemon. It keeps logs and gives system administrators a centralized spot to track and examine system activities.
8. NetworkManager: The network connections and configurations are managed by the NetworkManager daemon. It manages network interface configuration, detection, and automated connection while offering a simple user interface for network administration.
9. dbus-daemon: On a Linux system, the D-Bus daemon facilitates inter-process communication (IPC) between programs and services. It enables interaction and data sharing between several apps.
10. systemd: Many modern Linux distributions use the system daemon as their startup and service management system. It includes capabilities including process management, logging, and service dependency monitoring, as well as managing system services and the boot process.