Server Virtualization in Cloud Computing

Today we will discuss Server Virtualization, which is the second pillar of Cloud Computing.

What is Server Virtualization in CLoud Computing?

Server Virtualization is the process of dividing a physical server into several individuals and isolated virtual servers with software applications. Every virtual server can run its own operating systems individually.

Why Server Virtualization?

Server Virtualization is one of the most cost-effective methods to offer Web hosting services and uses the existing resources effectively in IT Infrastructure.

If there is no server Virtualization, the servers will only use a tiny section of their processing power. It will result in idle servers because the workload is divided into one portion of the network servers.

Data centers have become overcrowded with unutilized servers, resulting in wasting resources and heavy power consumption.

By having every physical server divided into multiple virtual servers, server virtualization will authorize each virtual server to behave as a unique device.

Every Virtual Server is capable of running its own application and operating systems.

The following process helps to increase resource Utilization by creating each virtual server to behave as a physical server, and it develops the capacity of every physical device.

Key Benefits of Server Virtualization

  • Server Virtualization contains higher server capability
  • Organizations experience cheaper operational cost
  • It eliminates the complexity of the server
  • It helps in developing the application performance
  • With Software Virtualization, users can deploy their workload swiftly.

Types of Server Virtualizations in Computing Network

1. Hypervisor in cloud computing

The Hypervisor is also popularly known as Virtual Machine Monitor. Basically, it is a layer that lies in between Operating System and Hardware. It offers essential services and features for a smooth process to run multiple operating systems.

It will identify the traps, respond to the priority CPU instructions, handle the ques, and dispatch and answer the requests of Hardware.

A Host Operating System will also work on the top of the Hypervisor to administer and manage the Virtual Machines.

2. Para-Virtualization in cloud computing

Para-Virtualization is dependent on Hypervisor. In this Virtualization model, many emulated and trapping overhead software are implemented and handled.

The guest Operating System will be modified and recompiled before the installation process inside the virtual machine. Because of this modification in the Guest Operating system, the performance increases, and the system will communicate directly with the Hypervisor, and the Emulation overhead gets eliminated.

  • Para-Virtualization is easy
  • It has no enhanced performance
  • It has no Emulation overhead.
  • Para-Virtualization requires modification to run the guest Operating System.

3. Full Virtualization in cloud computing

Full Virtualization is almost similar to Para-Virtualization. It has the capability to simulate the underlying Hardware when required. The Hypervisor will trap the machine operations done by the Operating Systems to perform I/O operations or modify the system’s status.

Once the trapping is completed, the following operations will be simulated in the software, and the status codes will be returned invariably as per the hardware delivery. It is the key reason why a whole operating system is capable of running on top of Hypervisor.

  • In total Virtualization Guest Operating System does not require modification.
  • Full Virtualization is complex
  • It is slower
  • Installing a new device is challenging

4. Hardware-Assisted Virtualization in Cloud Computing

Hardware-Assisted Virtualization can be related to Full Virtualization and Paravirtualization in operational terms except that it requires Hardware support.

Many Hypervisors are overhead because of trapping and Emulation of I/O Operations, and status instructions get executed and processed within the guest OS. It deals by depending upon the hardware extensions of x86 Architecture.

Also, unmodified OS can be run as the Hardware support for Virtualization purposes. Secondly, it can be utilized to manage the hardware access and it will request the privileged and protected operations to communicate with the Virtual Machine.

  • In Hardware-Assisted Virtualization, the Guest Operating System has to perform any modifications.
  • The Hypervisor is overhead with a lower rate.
  • Hardware-Assisted Virtualization requires Hardware support.

5. Kernel Level Virtualization in Cloud Computing

Apart from using a Hypervisor, it will run a different version of Linux Kernel, and it is associated with Virtual Machine as a user’s space process on the physical machine.

It makes it easy to run several virtual machines on a single host device. A device driver is used to establish communication between the main Linux Kernel and virtual machine. But remember, Processor support is essential for Virtualization.

A slightly modified QEMU process is made and utilized to display and execute the containers for virtual machines.

In multiple methods, the kernel Level Virtualization is a specialized form of Server Virtualization.

  • In Kernel Level Virtualization, there is no requirement for administrative software.
  • It has significantly less overhead.

Linux Kernel Virtualization requires Hardware Support.

6. System Level Virtualization in Cloud Computing

This will run several but logically separated environments in a single machine of the operating system kernel. It is also known as the shared kernel approach, as all virtual machines share the same kernel to host the operating system. It is dependent on the change root concept, and it is known as “chroot.”

Basically, “chroot” will begin during system boot-up. The kernel will make use of root filesystems to load the drivers and perform several initial stage system tasks.

It will later switch into another root filesystem using the chroot command to mount on an -disk file system and the final root filesystem. And it will continue system initialization and configure within the file system.

The chroot mechanism of system Level Virtualization is considered as an extension of the following concept. It will allow the system to begin the virtual servers by their processors, executing its relative own filesystem root directories.

The critical difference between system Level and Server Virtualization is that multiple operating systems can run on various virtual systems.

Suppose all the virtual servers share an exact copy of the operating system. In that case, it is known as system Level Virtualization, and if various servers have multiple operating systems it is titled Server Virtualization.

Advantages of system level virtualization
  • System-Level Virtualization is lightweight compared to entire machines.
  • It can host various virtual servers
  • It consists of developed security and isolation
Disadvantages of system level virtualization
  • There is a possibility that the kernel of any driver issue can destroy all virtual servers.

How does Server Virtualization Works?

In Server Virtualization, the virtual servers are wholly dedicated to performing a specific task. Each virtual server behaves like a physical device that is capable of running its Operating System.

The administrator of the software is capable of converting one physical server into various virtual servers.

Later these several servers are capable of using the processing power of all machines.
The computer’s CPU can run various processors, which offer the capability to run many complex tasks efficiently.

Advantages of Server Virtualization

1. Economic

When the division takes place in the physical server is partitioned into multiple virtual machines, they then further and then several operating system instances can launch, operate, and be managed inside the physical servers.

Thus, using a less physical server will help in reducing the cost of the server, and as a result, it will benefit the overall business.

2. Disaster Recovery

The data virtually travels from one server to another quickly and safely. Users can store the data at any location and retrieve it back from anywhere. The following process takes less time, and also the downtime is reduced.

3. Increased Productivity

If the physical servers are fewer, then they are easy to manage. So there are several tools available and will convert the services smoothly.

4. Quick Deployment and Provisioning

In some seconds, the user is capable of performing provisioning and deployment tasks. Server Virtualization permits replicating the existing Virtual Machine.

5. Energy Consumption is reduced.

Less Physical servers will lead to lower consumption energy as they produce a lot of heat if it is not used efficiently. It raises an important issue because of environmental changes.

6. Affordable Web Hosting

When multiple servers are adjusted on one computer, the servers rise virtually, and there is no additional expenditure.

7. Increased Efficiency

As there are fewer physical servers, the IT team will focus on those specific servers and it will thereby benefit them to focus on critical tasks and increase their efficiency.

8. Independent Restart of Each Server

Every server can be restarted individually, which will not affect other working servers.

9. Centralized Management

Software Virtualization has centralized management, and there is Full compatibility with the applications.

10. Migration

In Server Virtualization, live Migration is possible from the servers, and it can be carried out very quickly.

11. Easy to Update

In Server Virtualization, installing, updating, and setting up the software is done efficiently.

Disadvantages of Server Virtualization

  • If any servers go offline because of technical issues, the website hosted with its help will also be down.
  • Users must manage the Virtual Machines accurately by configuring and monitoring the movements.
  • The RAM requirement is more as RAM consumption increases as every Virtual Machine will occupy its location.
  • The disk space also increases during the increase of files in virtual machines.
  • Several links in a Single-chain must work together.
  • When several virtual machines perform their operations together under the same host, their performance might get affected.
  • The cost of software licenses may be an issue.


Server Virtualization has benefitted IT Businesses in multiple ways, either by minimizing their Hardware cost or offering other benefits, as mentioned in the above article.