Interview with CloudLinux: A Linux OS – Just for the Cloud?

(Ping! Zine Issue 42) – Shared web hosting has been and will continue to be a popular service offering. Considered to be the most affordable and popular type of web hosting for end users, shared hosting can create serious problems for web hosting providers. For example, what happens when a hosting account gets hacked or a user runs a script that utilizes the server’s entire resources and the server crashes? Other websites and hosting accounts on the server go down as well. And that’s a serious problem.
The downside of shared hosting is that hosting accounts are not isolated on the shared server. So when a website utilizes all the server’s resources, the entire server goes down. Sure, web hosts respond to resource spikes, but it takes a lot of man hours to get the issues resolved and the server back online quickly. Otherwise, other hosting account owners on the server start calling, creating helpdesk tickets, and opening chat requests, consuming your support team’s time and resources.
Placing multiple hosting accounts on a single server means one account’s performance can and will affect every other account on the server. Until now, there was no other way to deal with this type of problem as no server operating system (OS) has been capable of handling multiple hosting accounts on one server properly.
Meet CloudLinux 
CloudLinux OS by CloudLinux, is the first OS that addresses the problem at an OS level and is exactly what hosting service providers and datacenters need in order to provide rock-hard hosting stability. As a result, sudden resource spikes are no longer an issue.
I recently had a chance to interview Igor Seletskiy, founder and CEO of CloudLinux. CloudLinux is an innovative, privately funded company with headquarters in Princeton, NJ. The people behind the company have significant hands-on experience in the hosting business and datacenter market and understand hosting companies’ specific needs. Seletskiy gave me insight into CloudLinux and the CloudLinux OS and what it means to web hosting businesses and hosting businesses shifting to a cloud-based services model.
What is CloudLinux?
CloudLinux OS is the first commercial operating system that meets the specific needs and requirements of web hosting providers. CloudLinux OS includes kernel level technology LVE (Lightweight Virtual Environment) that allows web hosting providers to meter and control CPU resources on the fly on a per-user basis. CloudLinux delivers advanced resource management, better security, and performance optimization specifically targeted to a shared hosting environment. As a result, improved performance helps web hosting service providers and datacenters provide better support to their customers and reduce the amount of support calls and man hours needed to track down offending accounts.
CloudLinux is also a building block for multi-tenant clouds. The ability to meter resources and set limits is critical to anyone who wants to provide a high density, multi-tenant environment on the cloud. And CloudLinux delivers such abilities out of the box.
“CloudLinux is firmly positioned to provide the best OS for shared hosting companies (multi-tenant environments), says Seletskiy. “There is no other Linux distribution that was specifically developed to fit hosting companies’ needs.”
CloudLinux isolates and controls resource spikes to prevent servers from going down by using LVE, a technology that allows for application level virtualization. By virtualizing applications, you can ensure that a single website will not bring down or slow down an entire server, which is especially beneficial for multi-user environments such as shared hosting. Therefore, all hosting accounts on the shared server are isolated from each other, so if one hosting account starts using all the server’s resources, other websites on the server remain unaffected.
CloudLinux OS’ most popular feature
“Our main benefit to hosting companies is LVE technology. LVE technology allows hosting companies to limit resources for each and every tenant in a multi-tenant environment,” says Seletskiy. “Load spikes caused by individual clients are one of the top reasons for server downtime and instability. We are efficiently solving that problem.”
CloudLinux solves that problem by utilizing a kernel-level technology to set resource limits per user account. A website can never use more resources than what has been assigned so server operation will not be affected by performance of a single website or hosting account on the server. No other server OS has similar technology implemented into its core. CloudLinux is the only OS capable of distributing resources on a per-user level, which makes it the best choice for web hosting providers seeking stability and control of their shared hosting environment, especially if they plan to implement complex computing configurations such as cloud-based hosting solutions.
By setting resource limits for each user, CloudLinux OS prevents a single user from using too many resources and taking down or slowing down the entire server. Hosting companies no longer have to worry about a single customer causing load spikes that can cause downtime. As a result, the servers are more stable and support costs are lower. And customers that are getting restricted can be easily up-sold as quantifiable metrics can be shown to them. Additionally, because setting limits can prevent load spikes, higher server utilization can be achieved, which leads to higher density and better efficiency.
Additional CloudLinux features
In addition to LVE technology, CloudLinux has many other innovative features that hosting providers may find valuable:
 · Tenant isolation (all website accounts residing on the server are isolated from each other so if one account starts using too many server resources or goes down, others remain unaffected).
 · Application resource limits (you can set individual limits for your blog, applications, and your website so that a sudden spike to one will not take down the rest of your resources).
 · Easy conversion from CentOS and RHEL (conversion process takes 5 to 10 minutes using yum).
 · Commercial support (The CloudLinux support team is available 24/7 to answer your questions along with an active community forum).
 · Fast security patch releases (security patches are released promptly to keep your server and your customers’ websites safe).
Benefits of CloudLinux over standard OS
CloudLinux was designed from the ground up to outperform standard operating systems in many areas.
According to Seletskiy, “CloudLinux is a drop-in replacement for CentOS/RHEL that provides the ability to meter resources (like CPU, memory, connections) on a per tenant basis.” He adds, “This is in particularly high demand among shared hosting companies, those that are running on top of the cloud or using plain vanilla servers.”
 · CloudLinux provides resource isolation via LVE technology vs. multiple non-isolated websites per server with a standard OS.
 · LVE technology prevents individual websites from using too many resources, while with a standard OS any website can drain server resources for any reason.
 · LVE technology provides better security for users and protects servers from draining resources, while a standard OS offers no additional security or protection for users from hackers or scripts that drain the resources of a single website.
 · With CloudLinux, a single website cannot overload the server.
 · CloudLinux lowers risk, increases efficiency, and improves server performance, while a standard OS increases risk and lowers efficiency of servers.
“Distributions like CentOS and RHEL see enterprises as their customers,” says Seletskiy. “Hosting companies have a different set of needs than enterprises and we serve those needs. For example, security issues like local privilege escalation are considered minor issues in an enterprise environment (due to their servers being locked down), yet it is a critical vulnerability for hosting companies.”
Even more important for web hosting companies is CloudLinux virtualization technology actually allows providers to host more websites on a single server without any negative effect on its operation. As a result, hosting customers experience maximum uptime with increased server stability and security.
For shared hosting, increased server density with more accounts per server will lead to lower hardware, electricity, datacenter space, and management costs. Improved stability and security will reduce outages, allowing technical staff to spend less time managing servers that are down or causing issues on the network.
Getting started with CloudLinux 
Whether you are a shared hosting provider or a datacenter, CloudLinux delivers better efficiency and stability so you can build a more profitable business. CloudLinux offers innovative technology that will help hosting providers “crash proof” their servers. According to Seletskiy, starting with CloudLinux is easy.
“There is no server migration and no need to setup a new server, as we can convert existing production CentOS/RHEL servers on the fly, with just one reboot.” Deploying CloudLinux will enable shared hosting providers to consolidate and reduce costs, while maintaining the same or better level of service to their customers.
And if you want to build multi-tenant clouds — CloudLinux is the OS to use. CloudLinux was chosen as a base OS by Parallels Share Hosting NG platform — high availability, cloud like shared hosting environment because of the product’s ability to meter and limit resources. CloudLinux is also working with several large hosting providers to bring their platforms to the cloud as well as more traditional Platform as a Service (PaaS) clouds that are looking to improve their density and efficiency.
To learn more about CloudLinux and its innovative technology, visit
About Dave Young
Dave Young is a professional writer, technical writer, website auditor, marketing consultant, SEO guru, and founder of Young Copy, a leading promotional and technical writing services firm. Visit to learn how you can boost your company’s revenues.