Plesk files can be divided into six major groups responsible for different aspects of Plesk work. The diagram below shows these groups (components of Plesk) and the connections they have to each other and to external services that Plesk manages.

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Plesk components are as follows:

  • Plesk core. The core processes requests that Plesk receives from the Plesk GUI, command line interface, and XML API. The core contains scripts, binary files and other resources used to link Plesk components with each other and with external services.
  • Plesk database psa. The database stores information about Plesk objects, such as IP addresses, domains, user accounts, and so on.
  • sw-cp-server - a web server based on nginx. This serves requests to the Plesk GUI.

Plesk GUI - a web interface provided with sw-cp-server. The GUI is the main means of interaction with Plesk.

  • Command line utilities. The command line interface allows integration of third-party software with Plesk objects. In addition, it is a way for administrators to manage Plesk through the server shell. For more information on the Plesk command line interface, refer to Plesk Command Line Reference.
  • XML API. This interface is another way to integrate third-party software with Plesk. It allows Plesk objects to be managed remotely by sending specifically structured XML packets and receiving responses from Plesk. For more information on XML API, refer to Developer’s Guide: Read Me First and XML API Protocol Reference.

The Most Important Files and Directories

Plesk for Linux installs its main components into the following directory:

  • On RPM-based operating systems: /usr/local/psa
  • On DEB-based operating systems: /opt/psa

This directory (main Plesk directory) contains Plesk core files, command line utilities, log files and so on.

In addition, Plesk creates files and directories outside the main directory. The list below contains those that you are likely to use when administering Plesk.

  • The main configuration file containing paths to utilities, services and packages used by Plesk:

  • The initialization script for opening and closing services during server startup and shutdown procedures:


Initialization scripts for starting and stopping services with xinetd:


Find more information on xinetd at

  • Plesk database:

  • Backup files: