What is CloudLinux?

When you visit from web hosting provider website you will probably notice that almost everyone of them is promoting and talking about “CloudLinux”, it’s all over the place and it is related to security, stability and performance. On this guide we will show you what is CloudLinux, its main features and how to install most of its core components on your cPanel shared hosting server.


CloudLinux is one of the most popular technologies for web hosting and specially for shared servers. Created by Igor Seletsky and backed up by the CloudLinux Team, CloudLinux provides a secure and stable hosting environment allowing sysadmins and web hosting companies to work on a secure environments, knowing their users are safe and controlled inside the jailed cage they create for each one.

CloudLinux is an operating system, and the leading platform to improve server security, stability and performance. It works by isolating each user with certain amount of pre-allocated server resources.

This leads to a stable web hosting platform, with almost zero downtime, huge security between cPanel acccounts, and incredible performance.  CloudLinux OS helps you to reduce operation costs, technical support tickets and increases profitability of your company.

What is CloudLinux exactly?

We said that it is an operating system. But in fact, it is a group of kernel tweakings that after applied to the Linux distribution, allow Sysadmins and DevOps to better control their server resources and network usage.

This is done by virtualizing / caging each user inside their own virtual enviroment, this is called LVE (LightWeight Virtual Environment). Each LVE inside the shared hosting server have their own pre-defined amount of system resources to use. Altough, you can also set this to unlimited for all users.

The problem with traditional shared hosting environments

Shared hosting servers often host hundred of websites, each one with their own files, emails, databases. Most of them are hosting CMS applications that are vulnerable to attacks (like outdated WordPress, Joomla, Drupal installations).

In a normal shared hosting environment, no limits are set for the shared hosting accounts, and in case something gets screwed up on a website, it can start using a huge amount of resources of the entire server, this causes slow speeds for the rest of the websites, all users get affected because one single account problems.

In traditional hosting servers, you can not set real limits for system resources like CPU, I/O, network and RAM memory for example. And when problems are in front of you, finding the cause of the high load average between hundred of users can take some time if your system administration skills are not the best ones.

How can CloudLinux help shared hosting providers?

After setting your system resource usage limits, all your users are 100% isolated from each other. This means that if a particular user account gets a large DOS / flood (or even legitimate traffic) and it starts using tons of RAM, I/O and CPU, CloudLinux limits will prevent your server from going down due to high load average.

CL controls the stability of your server by isolating this attacked user for example. In this case, the only one affected will be this user in particular, and not the entire server, as it happens on unlimited shared hosting servers that do not establish any limits on the system resources.

As you see, Cloud Linux uses limits to protect system users against abusers, attackers and poorly written scripts.

CloudLinux Features

CloudLinux provides a few interesting modules that you can install into your server:

Recommended reading:

About the Author: Santiago Borges

Experienced Sr. Linux SysAdmin and Web Technologist, passionate about building tools, automating processes, fixing server issues, troubleshooting, securing and optimizing high traffic websites.

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