For anyone looking to improve the performance of web servers and provide customers with faster, more stable service, WHM/cPanel optimization is a critical step. Incorrect settings can lead to server resources being exhausted, slowdowns, and crashes. In this article, I will explain in detail all the steps you need to optimize your WHM/cPanel server from A to Z.

1. Server Software and Hardware Requirements

CPU: Should have at least 4 cores.
RAM: At least 8 GB, preferably 16 GB+.
Disk: NVMe or SSD is preferred.
Operating System: CentOS Stream, AlmaLinux, or CloudLinux is recommended.

2. Preparations Before WHM/cPanel Installation

Connect to the server with root.
Fully update the server:

yum update -y

Define the hostname (server name):

hostname server.yourdomain.com

Use a static IP address.

3. WHM Basic Settings

Disable unnecessary features from the "Tweak Settings" section.
Deactivate FTP usage, prefer SFTP.
Increase the minimum password length.
Activate SMTP Restrictions (prevents spam bots).
Activate PHP-FPM usage (for speed and stability).

4. Apache Web Server Optimization

Recommendation instead of Apache: Use LiteSpeed.
If Apache must be used, the following settings should be made:
- KeepAlive: ON
- MaxKeepAliveRequests: 100
- KeepAliveTimeout: 3 seconds
Activate mod_deflate and mod_expires extensions (gzip compression + browser cache).

5. PHP Settings

Keep the PHP version up to date (minimum 8.1 is recommended).
PHP memory_limit: 512M
PHP upload_max_filesize: 128M
PHP post_max_size: 128M
PHP max_execution_time: 300

6. MySQL/MariaDB Optimization

MariaDB is recommended (faster and more optimized).
Optimize the settings in the /etc/my.cnf file:

[mysqld]
max_connections = 500
query_cache_size = 64M
query_cache_type = 1
tmp_table_size = 256M
max_heap_table_size = 256M
innodb_buffer_pool_size = 1G

Analyze with scripts like MySQLTuner and make adjustments according to the recommendations:

perl mysqltuner.pl

7. Cache Mechanisms

Use Redis or Memcached for WordPress sites.
Enable Redis from the "Service Manager" section in WHM.
Choose the correct cache plugins: LiteSpeed Cache, WP Rocket, etc.

8. CloudLinux and CageFS Usage

You can assign separate resource limits to each user using CloudLinux.
You can isolate users with CageFS and increase server security.

9. E-Mail Optimization

Set limits in Exim settings:
- Daily mail sending limit: 500 (for each user)
Be sure to define DKIM, SPF, and DMARC records via DNS.
Protect inboxes using RBL lists (such as Spamhaus).

10. Security Settings

Install and activate CSF Firewall:

yum install csf -y
cd /etc/csf
sh install.sh

Activate ModSecurity.
Activate cPHulk brute force protection.
Restrict Root SSH access, only allow specific IP addresses.

11. Backup Optimization

From WHM "Backup Configuration" section:
- Select Incremental backup.
- Set up automatic backups to an external server (Google Drive, SFTP).
- Create weekly and monthly backup plans.

12. Monitoring (Tracking and Alarm System)

Monitor CPU, RAM, and disk usage in real-time by installing the Munin Monitoring plugin.
You can use more advanced monitoring software such as Zabbix or Netdata.

13. Log Tracking and Cleaning

Unnecessary log files should not grow. Set up automatic cleaning with "logrotate".

14. Extra Improvements

Activate Swap memory (for RAM saving).
If IPv6 is not used, turn it off.
Make adjustments in the /etc/sysctl.conf file for TCP optimizations.

15. SSL Certificates

Define SSL for all domain names using Let's Encrypt or AutoSSL.

16. WHM and cPanel Updates

Activate automatic updates.
Select "Stable" as the "Release Tier".

Conclusion: By following these steps, you can bring your WHM/cPanel server to maximum performance, both lighten your own workload and increase customer satisfaction.

Remember, a server's speed depends not only on its hardware but also on software optimizations!