Server Virtualization Complete Guide

Posted on Jun 16, 2022

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If you want to save on IT costs while maximizing the existing IT infrastructure resources, server virtualization could be worth your consideration. This technique of deploying multiple server applications on one physical system has seen broader adoption in the market, and it's proving quite beneficial for small and large businesses alike. Below, we discussed more on server virtualization, from what it is, its types, pros, cons, and everything in between.

What is Server Virtualization?

Server virtualization refers to the process of creating servers, infrastructures, services, and multiple computing resources on one virtual platform. Initially, computer software and hardware were designed to support single applications. As a result, servers were forced to process one task at a time, which led to wastage of memory capacity and unused processors.

So as additional apps and services were deployed across the organization, the number of servers grew exponentially. Data centers were stretched to their limits by the rising prices and increased demand for space, power, cooling, and maintenance.

With the emergence of server virtualization, all of that changed. Here, one physical server is divided into numerous individual and remote virtual spaces, each serving various users. In other words, virtualization adds an extra layer of software to a computer, which controls the computer's virtualized resources, dividing them into logical instances known as virtual machines. The latter is capable of functioning independently. This minimizes the enterprise's IT costs by reducing server counts, easing the burden on data center resources, and improving IT flexibility.

Server Virtualization

How Does Server Virtualization Work?

Server virtualization works by extracting /isolating a hardware component from any software in which it is installed. A hypervisor - a specialized software- is used to provide this abstraction. The hypervisor identifies the computer's physical resources, such as CPUs, memory, storage volumes, and network interfaces, and creates logical aliases for them. The true strength of a hypervisor lies in what can be done with those isolated resources, not in its abstraction.

In other words, a hypervisor creates logical models of computers or Virtual Machines (VMs) using virtualized resources. Each VM functions as a full-fledged computer. Once a VM is set up, it requires the installation of a full suite of software, including an operating system, drivers, libraries, and, finally, the desired corporate application. This allows an organization to run different operating systems on the same physical computer to handle diverse workloads.

Although virtualization allows multiple logical computers to be created from a single physical computer, the number of virtual machines (VMs) that can be created is limited by:

  • The physical resources available on the primary computer.

  • The computing requirements imposed by the corporate apps running in those VMs.

Types of Server Virtualization

There are several types of server virtualization. We've highlighted the most common types below.


The hypervisor, also known as Virtual Machine Monitor or VMM, acts as a layer between the operating system and the hardware. This software package develops and runs VMs and allows a single host machine to support numerous guests' VM by sharing its memory and processing resources.

It also handles queues, executes commands, and responds to hardware requests. Since the guest Virtual Machines are independent of the host hardware, they can maximize the system's available resources, allowing for greater IT mobility. The two types of hypervisors available for use are Bare-Metal hypervisors and Hosted hypervisors.

Full Virtualization

Full virtualization is a popular method that combines binary translation and direct execution. The operating system and corresponding hosted software are operated on top of virtual hardware, which separates the computer service demands from the physical hardware that performs them. The challenge with this technique is that it causes continuous traps to the hypervisor and intercepts privileged operations, e.g., the input-output instructions.

Para Virtualization (PV)

This is a virtualization upgrade in which the guest operating system is altered before it's installed inside a VM, allowing all guest operating systems to share resources. Here, virtual machines become readily available through interfaces tied to the similar underlying hardware. This functionality lowers costs and improves system performance by utilizing VMs that are underutilized in traditional hardware virtualization, hence alleviating full virtualization concerns.

Hardware-Assisted and Kernel Level Virtualization

Hardware-assisted type is similar to paravirtualization and full virtualization, except that it needs hardware support. Additionally, no modifications to the guest OS are required, and hypervisor overhead is reduced. On the other hand, Kernel Level Virtualization employs a distinct version of the Linux Kernel instead of a hypervisor, allowing numerous VMs to run on a single host.

Advantages and Disadvantages of Server Virtualization


  • Server consolidation: Since virtualization permits a single physical server to handle several operations, the total count of servers in an organization can be decreased.

  • Simplified physical infrastructure: The total count of racks and cables in the data center is drastically decreased, thanks to the fewer servers used.

  • Reduced hardware and facilities costs: Consolidating servers minimizes the cost of data center hardware and facilities. This also reduces the overall maintenance costs for enterprises.

  • Increased server adaptability: Because each VM is its own separate instance, it must run its own operating system. On the flip side, the OS can differ between VMs, allowing the organization to run any combination of Windows, Linux, and other operating systems on the same physical hardware.


  • Increased Risk: Using the same physical computer to run numerous workloads poses a risk to the business. Multiple workloads can be affected by a server failure in virtualization, thereby creating further interruption to the organization, its employees, partners, and customers.

  • Virtual server sprawl: Unused or redundant virtual machines continue to consume precious server resources while doing little valuable work; in the meantime, those resources are unavailable to other virtual machines. As VMs multiply, the organization's resources get depleted, compelling it to make unanticipated capacity investments.

  • VM Licensing: Hypervisors and accompanying virtualization-capable management tools add to the organization's costs. Hypervisor licensing must be closely controlled to ensure that the software's licensing agreements' terms and conditions are followed.

  • Requires Professional Servicing: Professional IT personnel must adopt and manage a virtualized environment successfully.


Server virtualization serves firms in the IT industry in various ways, including lowering hardware costs and streamlining physical infrastructure. Still, virtualizations come with some drawbacks, so you want to keenly weigh the pros and cons with respect to your organization's IT needs. Before deploying server virtualization, consult an expert IT professional to help you choose a virtualization technique that will guarantee the most benefits to your firm.

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