Install PHP

Overview

OpenLiteSpeed uses lsphp (LiteSpeed PHP) as its default PHP processor. lsphp is a PHP build optimized for LiteSpeed’s native LSAPI protocol, delivering significantly better performance than PHP-FPM or standard FastCGI.

Add the LiteSpeed Repository

RHEL / AlmaLinux / Rocky Linux

rpm -Uvh https://rpms.litespeedtech.com/centos/litespeed-repo-1.3-1.el9.noarch.rpm

For EL8 systems, replace el9 with el8.

Debian / Ubuntu

wget -O - https://repo.litespeed.sh | sudo bash

Install lsphp

Available Versions

The LiteSpeed repository provides the following PHP versions:

Package prefix	PHP version	Status
lsphp74	7.4.x	Security fixes only
lsphp80	8.0.x	EOL
lsphp81	8.1.x	Security fixes only
lsphp82	8.2.x	Active support
lsphp83	8.3.x	Active support
lsphp84	8.4.x	Active support (recommended)

Install PHP 8.4 with Common Extensions

RHEL / AlmaLinux / Rocky:

dnf install lsphp84 lsphp84-mysqlnd lsphp84-xml lsphp84-gd \
  lsphp84-mbstring lsphp84-opcache lsphp84-curl lsphp84-json \
  lsphp84-zip lsphp84-bcmath lsphp84-intl

Debian / Ubuntu:

apt install lsphp84 lsphp84-mysql lsphp84-xml lsphp84-gd \
  lsphp84-mbstring lsphp84-opcache lsphp84-curl \
  lsphp84-zip lsphp84-bcmath lsphp84-intl

List All Available Extensions

# RHEL-based
dnf list lsphp84-*

# Debian-based
apt-cache search lsphp84

Link lsphp to OLS

OLS looks for the PHP binary at /usr/local/lsws/fcgi-bin/lsphp. Create a symlink to the installed version:

ln -sf /usr/local/lsws/lsphp84/bin/lsphp /usr/local/lsws/fcgi-bin/lsphp

To switch PHP versions later, update this symlink to point to a different lsphp binary (e.g., lsphp83).

Verify the Installation

/usr/local/lsws/lsphp84/bin/lsphp -v

Expected output:

PHP 8.4.x (litespeed) ...

Note the (litespeed) SAPI identifier — this confirms LSAPI support is compiled in.

Multiple PHP Versions

You can install multiple lsphp versions simultaneously and assign them to different virtual hosts. Install each version:

dnf install lsphp83 lsphp84

Then configure separate external applications in httpd_config.conf for each version, pointing to the correct binary path:

extprocessor lsphp83 {
  type                    lsapi
  address                 uds://tmp/lshttpd/lsphp83.sock
  maxConns                10
  env                     PHP_LSAPI_CHILDREN=10
  initTimeout             60
  retryTimeout            0
  respBuffer              0
  autoStart               1
  path                    /usr/local/lsws/lsphp83/bin/lsphp
  backlog                 100
  instances               1
}

PHP Configuration

The php.ini for each lsphp version is located at:

/usr/local/lsws/lsphp84/etc/php/8.4/litespeed/php.ini

After modifying php.ini, restart OLS to apply changes:

systemctl restart lsws

Next Steps

• PHP LSAPI — understand how LSAPI works and tune it
• PHP Environment Variables — configure PHP worker processes
• PHP-FPM Integration — use PHP-FPM as an alternative