Virtualization is not new to computing. Over the last decade, the web hosting industry has used various server virtualization tools to create virtual servers for web hosting. When you decide to buy web hosting, you can choose the traditional shared or dedicated server hosting plans, or opt for the virtualization-driven VPS Server hosting or cloud hosting plans.
A site hosted on a VPS Server is stored on a virtual server that has full root access, dedicated resources, and account isolation. These virtual servers are created using server virtualization software called a hypervisor. The hypervisor is responsible for creating multiple virtual servers on a physical web server with dedicated resources and account isolation. Over the years, there have been different types of server virtualization tools to help hosting providers create virtual servers. Today, we are going to talk about two of the most popular ones – KVM and OpenVZ or OVZ and compare them to help you find the best VPS hosting for your needs.
Understanding KVM and OpenVZ
Kernel-based Virtual Machine or KVM is a Linux-native server virtualization solution that allows Linux to perform the functions of a hypervisor. It offers a range of powerful features making it one of the most commonly used virtualization solutions for creating a virtual server.
OpenVZ or OVZ is a container-based server virtualization solution. This allows the host to share the hardware of the server by using a layer of abstraction. OpenVZ creates containers that use the host’s kernel but have independent operating systems and applications.
Comparing KVM and OpenVZ
Here is a quick look at the comparison between KVM and OpenVZ:
Compatibility with Operating Systems
- KVM – Apart from Linux, since KVM is built into the Linux OS, it also offers support for guest operating systems including Windows, Solaris, Haiku, and many others
- OpenVZ – Since OpenVZ creates containers and depends on the host kernel, it only supports the Linux operating system
- KVM – KVM needs a hypervisor with specific hardware requirements. Hence, you need to reserve some resources for the hypervisor and cannot distribute all computing power among virtual machines
- OpenVZ – OpenVZ offers OS-level virtualization. Therefore, there are no additional resource requirements for it. Hence, you can allocate up to 99% of the server’s resources among virtual servers.
- KVM – When the host uses KVM for creating virtual machines, there is a fixed limit on the memory available to each virtual environment. Hence, you can expect a stable performance since the memory available to you does not depend on the overall memory usage of the physical server.
- OpenVZ – In OpenVZ, the overall memory is available for all virtual servers to use. However, if there is a spike in RAM usage by one container, then the performance of other containers can get impacted.
While both solutions are open-source and hence, free, the additional hardware requirements of KVM make it costlier than OpenVZ to implement.
When you decide to buy VPS Server hosting, you need to choose between Windows and Linux VPS Hosting, HDD and SSD Hosting, and unmanaged and managed VPS hosting. Apart from these factors, the virtualization technique used by the host should also be considered since it can impact the performance of the virtual server and your site. Make sure that you talk to the hosting provider and spend some time understanding the type of virtualization used before making a decision. Good Luck!