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What is CloudLinux

  • More stable - Less downtime
  • More secure

CloudLinux is a Kernel-level technology that helps provide for a more stable hosting environment. This is accomplished by protecting your site against the bad neighbor effect. What this means is that CloudLinux will prevent a single site from crashing a server, making your site unresponsive. When a single customer's site starts consuming too much of the generous amount of server resources, CloudLinux will throttle just that site to allow it to continue operating up to a safe server level, while at the same time fully protecting your site from 'bad neighbor'.

CloudLinux CageFS Software

CageFS further increases security on top of the kernel-level benefits described above. It is a virtualized file system and a set of tools to contain each user in its own 'cage'. Once installed, each account on the server will have its own fully functional CageFS, with all the system files, tools, etc. With CageFS, only safe binaries are available to the user. Said user will not see any other accounts on the server and would have no way to detect the presence of other users & their user names on the server. CageFS also prevents a user from seeing server configuration files, such as Apache config files.

At the same time, the user's environment will be fully functional, and they should not feel in any way restricted. No adjustments to a user's scripts are needed. CageFS will cage any scripts execution done via Apache (suexec, suPHP, mod_fcgid, mod_fastcgi), LiteSpeed Web Server, Cron Jobs, SSH, and many more services.

Cloudlinux PHP Selector uses CloudLinux on all of our shared servers, but a license to add it to a VPS is completely optional. One of the benefits (among the others outlined above) is access to something called 'cl.selector', AKA CloudLinux PHP selector. This allows us to change PHP versions on a per-site basis (for example, you might require PHP version 5.5 on one website, and 5.6 on another. Without cl.selector, this would not be possible) as well as change the PHP modules per-site.

CloudLinux offers a very simple to install and use PHP selector. The first step in the install process is to set up a CloudLinux license. At current, these are $13.95 a month for our VPS customers. CloudLinux boasts not only accessibility via the various reliable plugins it offers (like the PHP selector) but increases server security, and allows you to limit resource usage across all accounts on your VPS with an in-WHM menu.

To access the PHP selector, simply click the 'Select PHP Version' button in the control panel for any site. Once done, use the drop-down to select the PHP version you need and then click 'set as current'.

Get with our support team today if you would like the CloudLinux PHP Selector to your VPS, or any of the other software included in the CloudLinux Suite.

What to do if your site is being throttled by CloudLinux

This would be a very rare situation. However, if your site is the one potentially causing server problems (ie, the 'bad neighbor), which means your site is being throttled and seems to work sometimes and not others, or maybe just not working for the most part, this means your site is consuming too many server resources. We have these throttle limits so high that if your site is hitting these limits, generally it should not be on any shared hosting environment.

The one exception to that would be if your site has hundreds or thousands of pages and a bot is heavily crawling your site. If that is the case, we suggest you add a Crawl-Delay setting to your robots.txt file to slow down the bots. Generally setting the Crawl-Delay to 10 will suffice.

In the rare case that your site does get throttled by CloudLinux, we suggest looking at your log files to see what may be causing the problem. If you just have a ton of traffic (ie, way beyound normal shared hosting) then you really need to get a VPS asap. If you have a run-away script, then you should review the code for that to see if you can find/fix the problem.