What is server virtualization

Term of the Day. Best of Techopedia weekly. News and Special Offers occasional. Server Virtualization. Techopedia Explains Server Virtualization. What Does Server Virtualization Mean? Techopedia Explains Server Virtualization Typical enterprise data centers contain a huge number of servers. Related Question What is the difference between cloud computing and virtualization?

Share this Term. Tech moves fast! Stay ahead of the curve with Techopedia! Servers are the technology that hosts files and applications, providing functionality for other programs. This device processes requests and delivers data to other computers in a local area network LAN or wide area network WAN. Servers are often very powerful, processing complex tasks with ease. A single server can only use one operating system OS and is usually dedicated to a single application or task.

This is because most applications do not function effectively together on a single server. However, when a server is virtualized it is transformed into multiple virtual servers which can each run different operating systems and applications in an isolated environment. This means less wasted processing power. Servers take up space and require maintenance, as well as needing to be housed in an environment that is cool and dust-free.

Between hardware costs, maintenance costs, and cooling costs, this can often become a significant cost to organizations. Server virtualization is important because it is significantly more efficient than using individual servers for each application or task. Not only does server virtualization reduce the number of physical servers needed, but it also simplifies the management of those servers, reduces costs associated with housing and maintaining servers, and results in significantly less wasted resources.

Server virtualization minimizes costs by increasing the utilization of existing resources. This cuts down on the number of physical servers needed, minimizes management costs for those servers, as well as reducing the energy requirements needed to run the servers and provide cooling for the servers. These are modified by implementing an API application programming interface to enable them to communicate through hypercalls.

Learn more about Bare Metal Cloud. Virtualization at the OS level is a feature of an operating system which has a kernel that allows the existence of multiple user-space instances. We call this type of virtualization containerization and these user-space instances containers partitions, virtual environments or jails. Programs can run inside the container but are restricted only to the content of the container and devices assigned to that container. Unlike the primary OS, these user-space instances believe they have all available resources but are limited to the resources allocated to the container.

As this level of virtualization uses the same OS and kernel as the host, it can only differ from its host by the version of OS. Type 1 or bare-metal hypervisors are installed directly on the physical hardware of the host machine, providing a layer between the hardware and an OS. On top of this layer, you can install many virtual machines. The machines are not connected in any way and can have different instances of operating systems and act as different application servers.

System administrators and advanced users control the hypervisor remotely through an interface called a management console. With it, you can connect to and manage instances of operating systems. You can also turn servers on and off, transfer operating systems from one server to another in case of downtime or malfunction and perform many other operations. Also, it controls and assigns the resources allocated to each virtual machine based on its usage to avoid wasting resources.

Unlike type 1, a type 2 hypervisor is installed on top of an existing operating system. This allows users to utilize their personal computer or server as a host for virtual machines. Therefore, you have the underlying hardware, an operating system serving as a host, a hypervisor and a guest operating system.

Note: The guest machine is not aware of its part of a larger system and all actions you run on it are isolated from the host. Although a VM is isolated, the primary OS is still directly connected to the hardware.

This makes it less secure than type 1 hypervisors. In environments where security is paramount, this type of hypervisor may not suit your needs. However, end-users and clients with small businesses may find this type of environment more fitting. Having a hosted hypervisor allows more than one instance of an operating system to be installed. However, you should be careful with resource allocation. In the case of type 2 hypervisors, over-allocation may result in your host machine crashing.