What is Hypervisor in Cloud Computing

What is Hypervisor?

Hypervisor is a program that allows multiple Operating Systems to share a single physical hardware. Each operating system will share the host’s processor, memory, file storage, and other resources. The hypervisor controls the host processor and resources, allocating what is needed to each operating system. This ensures that he the guest operating systems (called virtual machines) cannot interrupt each other.

Since Hypervisors help create and manage virtual machines (VMs), they are also known as Virtual Machine Monitors or VMMs.

Hypervisors help you retain control over a cloud environment’s processes and infrastructure and protect sensitive data. It makes cloud-based applications accessible to users in a virtual environment.

Types of Hypervisors

There are 2 types of Hypervisors, as detailed below:

Type 1 Hypervisor

Type 1 Hypervisor is installed directly on the physical server, also called a “bare metal” Hypervisor. You can also have direct access to the resource of the physical server, which makes the Type 1 Hypervisor highly effective. Furthermore, the design of the Type 1 Hypervisor is highly secure, as it limits the attack surface and the potential for compromise.

Type 1 Hypervisors are the most common choice within the enterprise IT context as it offers strong security, stability, and performance.

Popular Type 1 hypervisors are Nutanix AHV, VMware ESXi, Citrix Hypervisor amongst others.

Type 2 Hypervisor

Type 2 Hypervisors run as applications on a physical server’s pre-existing OS. The host operating system, sits between the physical server and the Hypervisor. So, it is also called “hosted” Hypervisors.

However, Type 2 Hypervisors are not a good choice for server-based environments, as they have higher latency and risk exposure than Type 1. Type 2 Hypervisors are easy to install. It can work well in specific use cases, like individual PC users who want to run only one OS. In such cases, performance and security are not principal concerns.

Example: Installing Linux over Windows using VirtualBox

What is a Cloud Hypervisor?

A Cloud Hypervisor is a software solution that enables you to share the physical computing and memory resources of a cloud provider across multiple virtual machines (VMs).

It was created for mainframe computers in the 1960s. Cloud Hypervisors gained worldwide popularity with introduction of VMware for industry-standard servers in the 1990s.

Cloud Hypervisor allows the single physical server to run multiple guest Virtual Machines. These VM’s each have their own operating systems (OSs) that run independently and are logically separated from each other. Because of this problems or crashes in one guest VM have no effect on the other guest VMs, OSs, or it’s running applications.

Why do you need a Cloud Hypervisor?

Suppose you own a company with multiple servers that provide various services to customers via the internet. In that situation, it isn’t easy to centrally handle them, particularly those running different operating systems.

A Hypervisor allows you to virtualize these servers and manage them all in one physical machine, making them more efficient. It also helps you to control the data flow into the virtual machines managed by the Hypervisor.

Hypervisor also acts as a storage center where all the data is stored virtually.

How does a Cloud Hypervisor work?

Following 3 modules are used in a HyperVisor

• Dispatcher: This module acts as an entry point for the Virtual monitor. It also reroutes all the virtual machine instructions to one or both modules listed below.
• Allocator: The allocator is responsible for deciding the system resources to be provided to the virtual machine instance. In other words, the dispatcher invokes the allocator whenever a virtual machine executes an instruction that results in changing machine resources associated with the virtual machine.
• Interpreter: The interpreter module contains routines executed whenever a virtual machine executes specific privileged instructions.

Benefits of a Cloud Hypervisor

Here are some important advantages/pros of Cloud Hypervisor:

• Portability: Applications that experience spikes in demand can connect two additional machines to scale as needed. It becomes possible as hypervisors allow workloads to move between two different virtual machines.
• Efficiency: One physical server can be used more effectively when multiple virtual machines run on one physical machine’s resources, thanks to Hypervisors.
• Utilization: Hypervisors allow multiple virtual machines (VMs) to run on a single physical server and share resources. Thus, it increases server utilization while saving on power, cooling, etc.
• Hardware neutral: Hypervisor-based replication is hardware neutral, meaning duplicate data can easily be stored on any device.
• Flexibility: The Hypervisor guest VMs and OSs on a wide range of hardware.
• Time to use: Cloud Hypervisors enable virtual machines (VMs) to be instantly turned up or down. It allows projects to be created and teams to work on the same day.
• Reliability: Hardware failures can be remedied by moving virtual machines to different machines.

Container vs. Hypervisor

Containers and Hypervisors are involved in making applications faster and highly efficient. However, they achieve this same goal differently.

Here are some important differences between Container and Hypervisor:

Containers	Hypervisor
Containers as a service is a type of infrastructure primarily geared toward running a single application.	A Hypervisor also called a virtual machine monitor, is software that creates and runs virtual machines (VMs).
It can run on any operating system. The only requirement is a corresponding container engine.	It shares virtual computing, storage, and memory resources.
It allows applications to run without the need for an operating system.	It allows an OS to run independently from the underlying hardware using virtual machines.
They are extremely portable because an application contains everything it requires for running.	It can run on multiple operating systems or be installed on the standard operating system.

How to choose the right Hypervisor?

Here are important things you need to consider for selecting the right Hypervisor:

• The cost of a Hypervisor: The most significant determining factor in selecting a Hypervisor should be to strike the right balance between cost and functionality. Several entry-level solutions are free but do not offer the necessary features.
• Virtual machine performance: Virtual systems should be able to meet or even exceed the performance of their physical counterparts, so everything beyond meeting this benchmark is undoubtedly profitable.
• Ecosystem: Selecting a Hypervisor with a great ecosystem is also essential. It’s desirable to have documentation, support, training, third-party developers, and consultancies available for your chosen Hypervisor.
• Test yourself: You can run various Hypervisor systems and determine which is right. It can be tested on your existing Desktop or Laptop.
• Performance – It should be able to deliver enough performance to support your mission-critical applications.
• OS Support–Does it support popular guest operating systems like Microsoft, Suse, RedHat, Ubuntu, and CentOS.

Example of Hypervisor

Here are some famous examples of Hypervisors:

• KVM: KVM is virtualization software that provides virtualization infrastructure and a processor-specific module. It enables you to run multiple virtual machines on unmodified Images on Windows or Linux operating systems. It also helps you to do scheduling and resource control.
• VSphere: VMware vSphere is a server virtualization software application from VMware. IT departments can run application workloads on the most efficient and cost-effective computer resources. It offers an effective central management system for hosting multiple machines or servers using virtualization.
• XenServer: Citrix XenServer is an open-source server virtualization platform based on the Xen Hypervisor. This Hypervisor platform enables the creation and management of virtualized server infrastructure.

Summary

• A Hypervisor also called a VMM (virtual machine monitor), is software that creates and runs virtual machines (VMs).
• Hypervisors use one or more systems available resources and provide greater IT versatility.
• Two types of Hypervisors are Type 1 and Type 2.
• A Cloud Hypervisor is software that allows sharing of a cloud provider’s physical computing and memory resources across multiple virtual machines.
• The cost of a Hypervisor, Virtual machine performance.
• Ecosystem, Test for yourself, performance, ecosystem, etc.
• KVM, VSphere, and XenServer are some most common types of Hype visors.