Installing and Managing PHP Versions in Plesk Obsidian

Plesk Obsidian offers robust support for various PHP versions and handler types, providing unparalleled flexibility for diverse web hosting environments. This detailed guide will walk you through the essential processes of installing, uninstalling, and effectively managing additional PHP versions directly within your Plesk control panel, optimizing your server's capabilities.

Installing and Uninstalling PHP Versions

To effectively manage the PHP versions available on your server, whether you are installing a new version or removing an existing one, please follow these straightforward steps:

1. Navigate to Tools & Settings, then select Updates (located under the “Plesk” section), and subsequently click on Add/Remove Components.
2. The next step depends on your Plesk installation type:
   • (For Plesk on Linux systems) Expand the Web hosting section, and then proceed to expand the PHP interpreter versions section.
   • (For Plesk on Windows systems) Expand the Plesk hosting features section.
3. On the components management screen, currently installed PHP versions are clearly indicated by a green checkbox icon, while those not yet installed are marked with a red cross icon. To install a desired PHP version, click its corresponding icon and then choose Install. Conversely, to remove a PHP version, click its icon and select Remove. For illustrative purposes, you might select PHP versions 8.3, 8.2, 8.1, and 7.4 for installation, while simultaneously marking PHP version 8.0 for removal.
4. Finally, click Continue to apply your selections and initiate the installation or removal process for the chosen PHP versions.

Upon the successful installation of any PHP version, Plesk automatically configures the standard PHP handler types for it, including CGI, FastCGI, and PHP-FPM, ensuring immediate and seamless usability without further manual intervention.

Important Considerations for PHP Management

When managing PHP versions within Plesk, it's crucial to be aware of specific considerations that can impact functionality and compatibility:

Enabling PHP-FPM on Older Operating Systems

For servers operating on older operating systems, such as CentOS 6.x, it is frequently necessary to manually install the PHP-FPM support from OS vendor component. This specific component is absolutely essential to enable and utilize the highly efficient PHP-FPM handler, which significantly improves performance for many web applications. You can locate and install this critical component within the Add/Remove Components tab, specifically navigating to the Web hosting > Nginx web server and reverse proxy server section.

Compatibility with Newer Operating Systems

When working with more contemporary operating systems, such as Debian 9, you might observe that certain older PHP versions (for example, PHP 5.6 and earlier) are not available for installation. This situation typically arises due to compatibility issues with the modern OpenSSL versions that these newer operating systems integrate, which may not fully support or function correctly with older PHP releases. Always check the official documentation for specific OS and PHP version compatibility matrices.

Plesk provides advanced configuration options that extend beyond basic installation. You possess the flexibility to precisely control which handler types are made available to your customers for each installed PHP version. For example, you could configure your server to allow customers to utilize both FastCGI and PHP-FPM with PHP 8.3, but restrict PHP 8.1 to only the PHP-FPM handler for enhanced performance and security. Furthermore, Plesk empowers you to configure specific PHP settings individually for every PHP version installed on your server, offering granular control over your hosting environment and allowing for fine-tuned optimization.

In Plesk Obsidian and all subsequent versions, the system PHP component is no longer a mandatory dependency. This significant enhancement introduces greater flexibility for administrators, enabling them to:

• Install Plesk without the inherent necessity of including a system PHP component during the setup process.
• Safely and effectively remove the system PHP component after completing an initial installation or upgrading to Plesk Obsidian.
• Install and efficiently utilize custom PHP builds, providing a robust alternative to the default system PHP component and allowing for highly specialized environments.

This increased flexibility and modularity ensure that you can meticulously tailor your Plesk environment to meet specific project requirements, leverage the most suitable PHP configurations, and maintain optimal performance for all your web applications.