With the evolution of new hosting technologies, solutions like VPS Hosting seems to be on the rise. As the name suggests, VPS runs on Virtual Private Servers which use virtualization to isolate servers from the host machine. A VPS network is designed in a manner wherein the main physical server is separated into multiple smaller servers. Each such smaller server is complete in itself with its respective hardware, applications, storage, and more. The technique of virtualization makes this hosting technology unique and more efficient. Now, there are two types of virtualization – KVM and OpenVZ.
Let’s look at what each of entail.
KVM or Kernel-based Virtual Machine is a technology that runs on the Linux kernel of VPS hosting server. It transforms the kernel into a hypervisor, which then helps create multiple virtual servers, also called guest machines. In a way, KVM is responsible for the isolation of servers on the host machine.
OpenVZ is a virtualization technology that runs at the operating-system level, which is usually Linux. Although the virtual servers are isolated, they all run on the same operating system, facilitated by OpenVZ.
Each of these technologies has its own advantages and disadvantages and come with respective functionalities.
Key differences between KVM and OpenVZ
KVM is highly versatile and customizable. While it runs primarily with Linux OS, KVM also supports almost all currently used operating systems like, CentOS 6 / CentOS 7 / Ubuntu 16.04 / Fedora 23 / Debian 8, Plesk Onyx, etc.
Furthermore, with KVM, you can always set the lowest or highest values for your resource utilization on the system. This allows you to use only what your applications need or demand, thus optimizing resources and performance at the same time. Since KVM helps isolate servers completely, each such server has its dedicated resources, which lets them function as an independent system, which also includes an independent kernel.
OpenVZ, on the other hand, can only run on a Linux OS. Also, since it makes the virtual servers run on a common operating system, it allows complete resource sharing. It operates on a shared kernel over the Linux OS, which is used by multiple users on the VPS network. So, in a way, although the guest machines are virtually separated, the kernel is common, and users cannot customize it as they want.
OpenVZ, with its shared OS option, makes it affordable and thus are popular among small-scale websites. KVM, on the contrary, comes with complete virtualized hardware and other server assets, which is dedicated to your account. This makes KVM VPS much costlier than OpenVZ.
OpenVZ, with its certain limitations, makes for a good platform for running small applications and are apt for websites which do not need a highly customized hosting environment. But, for resource-intensive websites and demands tailor-made hosting operations, as in dynamic sites like media and entertainment, gaming, e-commerce, and similar businesses, then KVM is the most suitable technology to be used.
There is no rule for which of these two technologies should you adopt. It all depends on what your website demands and what is your plan for scaling. Once you assess your requirements, you should discuss the same with your hosting provider who can help you with the right insight into the virtualization technology that you should opt for. Always research well, ask questions, and find the most optimal hosting solution for your business.