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Server Virtualization in Cloud Computing

Cloud Computing | Server Virtualization: In this tutorial, we will learn about server virtualization, types of server virtualization, how virtualization for servers functions, why is the virtualization of servers important, etc. By Rahul Gupta Last updated : June 03, 2023

What is Server Virtualization in Cloud Computing?

Server Virtualization is a technology that allows any operating system on a virtual platform to construct a virtual instance of it. Each operating system needed a physical platform, usually a server with a CPU, disc, memory, and other related hardware to house the operating system, before server virtualization became mainstream. An operating system has access to all of the host hardware's available computing power on a physical server. This approach has proven quite wasteful on hardware resource availability as servers have become more efficient.

How Virtualization for Servers Work?

To build virtual server instances we first need to set up virtualization software. It is an important software known as a hypervisor. Its main function is to build a virtualization layer that separates virtual instances from CPU/processors, RAM, and other physical resources. We can use the virtualization program to replicate physical resources and build a new virtual server on top of it once we install the hypervisor on a host machine.

Different forms of server virtualization exist. The difference between them is based primarily on the degree of isolation they provide, which is also linked to the number of hardware resources they emulate.

Why Server Virtualization is Important?

Server virtualization is important because it is substantially more effective for each application or task than using individual servers. Database virtualization not only decreases the number of physical servers available, but also simplifies the management of those servers, reduces the cost of housing and server maintenance, and results in substantially fewer resources being wasted.

Followings are the key points that show why is the virtualization of servers important:

1. Power Savings

Inherently, virtualizing servers is "green." Not only do servers need the energy to power them, but also need cooling energy. Because the number of servers required is greatly reduced by server virtualization, this results in reduced energy costs.

2. Faster Server Provisioning & Deployment

Since a new server is needed for most new applications, having a one-server-per-application configuration typically involves buying and installing a new physical server. This can be time-consuming, taking weeks sometimes. With virtual servers, however, server provisioning and deployment is easy and fast, as no new server or installation is needed.

3. Improved Disaster Recovery

Virtualization of servers makes it easier to implement an efficient plan for disaster recovery. This is because we can rapidly transfer information or programmes from one server to another. A large number of virtual machines can be housed on virtual machines (VMs). Because of this, building a replication site can be easy and efficient. The majority of virtualization software also helps to test failovers in disaster recovery, a protocol with a large number of physical servers that is almost impossible.

4. Minimize Costs

By increasing the use of existing resources, server virtualization minimizes costs. This reduces the number of physical servers available, minimizes the cost of operating those servers, and reduces the energy requirements needed to operate the servers and provide server cooling.

Types of Server Virtualization

1. Full virtualization

Full virtualization uses a hypervisor, a type of software that interacts with the storage space and CPU of a physical server directly. The hypervisor manages the resources of the physical server and keeps the other virtual servers separate and unaware of each virtual server. As it runs programmes, it also relays resources from the physical server to the right virtual server. The main constraint in using total virtualization is that a hypervisor has its own needs for processing. This can slow down apps and affect the efficiency of servers.

2. Paravirtual Machine Model

A fully virtualized environment might not be sufficient when we need many virtual machines and have flexible resource sharing. A para-virtualized environment can better serve the situation in this case.

The virtual model removes the VM's need to trap privileged commands, rendering the device more time-efficient and less intrusive. The operating systems understand a hypervisor's presence and interact with it directly by sending comments known as hyper calls.

3. OS-Level Virtualization

OS-level visualization does not use a hypervisor, unlike total and Para-virtualization. Instead, all the functions of a hypervisor are handled by the virtualization capability, which is part of the physical server operating system. However, in this Server Virtualization Process, all virtual servers must run the same operating system.