PHP
In the world of modern web development, PHP and Apache Web Server are two essential, complementary components. Both dominate server-side hosting environments for various companie and individuals managing CMS-based websites like WordPress, Joomla, Laravel, and others. This guide will cover how to install PHP on Apache Web Server AlmaLinux 8 in detail, from package installation to configuration testing.
Prerequisites
- Full
rootaccess - Apache/HTTPD installed
- Basic Linux Command Line
- Security
PHP Installation
The first step before installing PHP is to ensure that your system is up to date and ready to use.
dnf update -y
dnf install epel-release -y
After updating the system, we need to ensure that Apache Web Server (httpd) is installed. If it isn't, install it with the following command:
dnf install httpd -y
systemctl enable --now httpd
If you are using a firewall (such as firewalld), make sure the HTTP and HTTPS ports are open:
firewall-cmd --permanent --add-service={http,https}
firewall-cmd --reload
AlmaLinux 8 provides certain PHP versions by default. However, to get the latest version or a specific version like PHP 7.4, PHP 8.0, or PHP 8.1, we need to add the Remi repository.
Install Remi repository:
dnf install -y https://rpms.remirepo.net/enterprise/remi-release-8.rpm
Then list the available PHP using the following command:
dnf module list php
Sample output:
AlmaLinux 8 - AppStream
Name Stream Profiles Summary
php 7.2 [d] common [d], devel, minimal PHP scripting language
php 7.3 common [d], devel, minimal PHP scripting language
php 7.4 common [d], devel, minimal PHP scripting language
php 8.0 common [d], devel, minimal PHP scripting language
php 8.2 common [d], devel, minimal PHP scripting language
Remi's Modular repository for Enterprise Linux 8 - x86_64
Name Stream Profiles Summary
php remi-7.2 common [d], devel, minimal PHP scripting language
php remi-7.3 common [d], devel, minimal PHP scripting language
php remi-7.4 common [d], devel, minimal PHP scripting language
php remi-8.0 common [d], devel, minimal PHP scripting language
php remi-8.1 common [d], devel, minimal PHP scripting language
php remi-8.2 common [d], devel, minimal PHP scripting language
php remi-8.3 common [d], devel, minimal PHP scripting language
php remi-8.4 common [d], devel, minimal PHP scripting language
Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled
Enable the desired PHP module version. For example, for PHP 8.4, use:
dnf module reset php -y
dnf module enable php:remi-8.4 -y
Once the repository is active, we can proceed with installing PHP along with the commonly used essential modules:
dnf install -y php php-cli php-common php-mysqlnd php-fpm php-opcache php-gd php-curl php-mbstring php-xml php-json
Check the installed PHP version:
php -v
Here is an example of the output:
PHP 8.4.10 (cli) (built: Jul 2 2025 02:22:42) (NTS gcc x86_64)
Copyright (c) The PHP Group
Built by Remi's RPM repository <https://rpms.remirepo.net/> #StandWithUkraine
Zend Engine v4.4.10, Copyright (c) Zend Technologies
with Zend OPcache v8.4.10, Copyright (c), by Zend Technologies
To see the installed PHP modules, run the following command:
php -m
Configure Apache for PHP Compatibility
Once PHP is successfully installed, we need to configure Apache to run PHP scripts. If you use mod_php, Apache will automatically recognize .php files once the relevant module is installed. Ensure the Apache configuration file in /etc/httpd/conf.d/php.conf contains the following directive:
AddType text/html .php
DirectoryIndex index.php
Restart Apache for the changes to take effect:
apachectl configtest
systemctl restart httpd
To test whether the PHP installation was successful and can be run through Apache, create a test file in the root directory of the web server:
echo "<?php phpinfo(); ?>" | tee /var/www/html/info.php
Access the file through a browser by typing your server's IP address or domain: http://IP_ADDRESS_SERVER/info.php. If the PHP Info page appears, PHP has been successfully integrated with Apache.
PHP Production
Some important settings that are often modified when running PHP in a production environment.
| Parameters | Main Functions | Production Recommendations |
|---|---|---|
expose_php = Off | Hides the PHP version from the X-Powered-By HTTP header. Prevents system information from leaking. | ✅ Must be disabled |
display_errors = Off | Disables display of errors to the browser. Protects against sensitive information. | ✅ Must be disabled |
log_errors = On | Enables logging of all errors to an internal log file. Very useful for debugging. | ✅ Required |
error_log = /var/log/php_errors.log | Location of the PHP error log file. Make sure this file is writable by PHP-FPM. | ✅ Recommended |
memory_limit = 512M | The maximum memory limit used by a single PHP script process. Avoid setting it too small or too large. | ✅ As needed |
upload_max_filesize = 128M | The maximum file size that can be uploaded via the form. | ✅ Adjust to your needs |
post_max_size = 128M | Total POST data size limit (including file uploads). Must be ≥ upload_max_filesize. | ✅ Customize |
max_execution_time = 300 | Maximum script execution time (in seconds). Protects against scripts that loop too long. | ✅ Required setting |
date.timezone = Asia/Jakarta | Specifies the server's time zone. Important for log times, cache, cron, etc. | ✅ Customize locale |
To modify php.ini, go to /etc/php.ini. After making the modifications, restart php-fpm:
systemctl restart php-fpm
The PHP-FPM configuration is located in /etc/php-fpm.d/www.conf. The following parameters can be adjusted:
Performance tips: Adjust pm.max_children to the server's RAM capacity.
pm = dynamic
pm.max_children = 50
pm.start_servers = 5
pm.min_spare_servers = 5
pm.max_spare_servers = 35
After making changes to php-fpm, please restart the php-fpm service:
systemctl restart php-fpm
The following is an explanation of the parameters above:
Request Incoming
↓
[ Idle Worker ] ←--- set by min/max_spare_servers
↓
[ Active Process ]
↓
[ Done → idle again or stopped ]
pm
This mode determines the process management mode.
static: the number of worker processes is fixed (constant).dynamic: processes are created and terminated as needed.ondemand: processes are created only when requested and terminated when idle.
dynamic is the most common and is suitable for production servers with variable traffic.
pm.max_children
The maximum number of PHP processes (child processes) that may run simultaneously.
- This is the upper limit. If more than 50 PHP requests are active, the remaining requests will be queued until a worker is free.
- Too large → risks consuming RAM and swap.
- Too small → bottlenecks, slow response during high traffic.
(Total RAM - RAM for the system) / memory per PHP process
Example: If a single PHP process takes approximately 30MB, and the server has 2GB of RAM:
(2048MB - 512MB OS) / 30MB ≈ 51
pm.start_servers
Number of PHP-FPM processes that are immediately created when the service is first started.
- Too small → the initial request will wait for the worker to be created.
- Too large → high RAM consumption when idle.
5 is a safe value for servers with moderate traffic.
pm.min_spare_servers
Minimum number of idle processes (ready to use but not active).
- If the idle process is less than this, PHP-FPM will create a new process.
- Keep the system responsive to sudden requests.
pm.max_spare_servers
Maximum number of idle processes (not active but waiting for requests).
- If it's higher than this value, PHP-FPM will terminate some idle processes.
- Save RAM during low traffic times.
Troubleshooting
- Apache Not Executing PHP Files (Files Downloaded)
When accessing .php, the browser downloads the file instead of executing it. The solution is to ensure the following configuration is in place in the VirtualHost or global configuration:
<FilesMatch \.php$>
SetHandler "proxy:unix:/run/php-fpm/www.sock|fcgi://localhost"
</FilesMatch>
Also make sure php-fpm is running:
systemctl status php-fpm
- PHP Not Installed or Incompatible Version
php -v did not return information, or the PHP version is not as expected. Make sure you are using the Remi repository:
dnf install -y https://rpms.remirepo.net/enterprise/remi-release-8.rpm
dnf module reset php -y
dnf module enable php:remi-8.4 -y
dnf install php
- 500 Internal Server Error when Accessing PHP Files
The website displays a 500 error when executing a PHP file. This is usually caused by incorrect file/directory permissions. Ensure the file permissions are 644 and the directory permissions are 711 or 755. Troubleshoot by enabling error logging:
log_errors = On
error_log = /var/log/php_errors.log
- phpinfo() Not Showing
Make sure the info.php file is placed in the DocumentRoot:
<?php phpinfo(); ?>
- PHP-FPM High CPU Usage
The php-fpm process is using up to 100% CPU. This is usually caused by application code or a possible compromised script. Please mitigate this by disabling the following functions:
disable_functions = exec,passthru,shell_exec,system
- Slow PHP Requests or Timeouts
The site is very slow or unresponsive during high traffic. Check if pm.max_children is large enough. If it isn't, processes will be queued. Use the following command to check:
ps -ylC php-fpm --sort:rss
Conclusion
Installing PHP on Apache Web Server on AlmaLinux 8 is a crucial step in building a robust, production-ready hosting server. By utilizing the Remi repository, we can choose the PHP version that best suits the needs of modern applications. Integration with PHP-FPM via FastCGI also provides high performance and efficiency, ideal for production environments.
The steps discussed include:
- System updates and Apache installation
- Installing PHP and additional modules
- Activating the PHP version via Remi
- Integrating with Apache
- Testing functionality with the
phpinfo()file - Adjusting configurations for security and performance
With this approach, your server is ready to run a CMS, framework, or custom PHP application efficiently, securely, and stably.
If you want a fast, secure, and optimized PHP installation without the hassle of manual configuration, don't hesitate to choose Focusnic—the best solution for professional server and cloud VPS installations.
Q: Is it mandatory to use the Remi repository?
A: Yes, if you want to use the latest or specific PHP version (such as PHP 8.1). The default AlmaLinux repository only provides the default version, which may be too old for a modern application.
Q: What's the difference between mod_php and php-fpm?
A:
mod_php: PHP runs within the Apache process. Simpler but less efficient.php-fpm: PHP runs separately via FastCGI. More efficient, stable, and scalable for production.
Q: Can I install more than one version of PHP?
A: Yes, using the dnf module install and managing versions via alternatives or a separate php-fpm pool. However, it requires advanced configuration and careful consideration.
Q: Where is the main PHP configuration file located?
A:
- Global:
/etc/php.ini - FPM:
/etc/php-fpm.d/www.conf
Q: How do I know which PHP modules are installed?
A: Use the command: php -m
Q: What's the difference between pm = dynamic and pm = ondemand?
A:
dynamic: creates a number of workers from the start, suitable for fluctuating traffic.ondemand: processes are only created when a request arrives, saving more RAM but being slower to respond to the first request.
Q: How do I know what the ideal pm.max_children value is?
A: Measure the average memory usage per process: ps -ylC php-fpm --sort:rss. Then calculate it based on the server's total RAM:
(Total RAM - System) / RAM per PHP process ≈ max_children
Q: Should I use socket (/run/php-fpm/www.sock) or TCP (127.0.0.1:9000)?
A:
- Socket is faster and more efficient for a single server (default:
/run/php-fpm/www.sock). - TCP is used if Apache and PHP-FPM are on separate servers or in different containers.
Q: Can PHP-FPM be used with Apache and Nginx simultaneously?
A: Yes, as long as each web server points to a different PHP-FPM pool or through the correct proxy.
Q: How can I tell if max_children is too small?
A: Look at the PHP-FPM error log.
[WARNING] server reached pm.max_children setting (50), consider raising it