LET’S LEARN ABOUT HYPERVISOR, IT’S TYPES AND COMPARISON WITH DOCKER

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In this, we are going to learn about hypervisors, types of hypervisors, and a comparison of it’s with docker.

WHAT IS HYPERVISOR

Virtualization

In simple words, we can say that a hypervisor is a layer of software that creates and runs many separate virtual machines (VMs) on a single piece of hardware. Before diving into the details of what a hypervisor is, we should understand the technology behind it, i.e., called virtualization.

Virtualization is basically the creation of a virtual form of a resource (server, workstation, operating system, storage space, network, or file). The underlying hardware partition virtualization process so that each partition runs as a separate virtual machine.

Hypervisor

This is where the hypervisor comes in. A hypervisor can also be thought of as the operating system of virtualized systems. It is software that partitions, abstracts, and isolates the operating system and applications of the underlying computer hardware. In Addition, It is a form of virtualization software used in cloud storage to divide and allocate resources across different hardware the program that provides partitioning, isolation, or abstraction is hypervisor virtualization. The hypervisor is a hardware virtualization technique that allows multiple guest operating systems (OS) to run on a host system at the same time. A hypervisor is also sometimes a virtual machine manager (VMM).

Features of Hypervisor

There are two main characteristics of the hypervisor:

  • Partitioning/Partitions
  • Resource Allocation

Partitions:

Hardware partition supervisor below. Partitioning is a method of making efficient use of abundant hardware resources by allowing multiple independent software to run concurrently on the same hardware.

Resource Allocation:

The hypervisor manages independent virtual machines by distributing resources like memory, network bandwidth, etc. between them.

How does a hypervisor work?

  • Supervisor works at the server level and can be physical or virtual and is defined by hardware or software.
  • Virtual machine guest OS load monitor
  • Computer resource distribution monitor such as processor, memory, bandwidth, and disk storage for each virtual machine. It does this by creating pools of hardware resources, which it then allocates to virtual machines.
  • The virtual machine can make requests to the hypervisor through API calls.

To know how they work let us understand the types of Hypervisor

TYPES OF HYPERVISOR

There are two types of Hypervisors we have, they are:

  • Type I
  • Type II
  • KVM

TYPE I HYPERVISOR:

  • Type I are also called as Bare metal and Native Hypervisors.
  • They directly run the server’s hardware or host machines directly , so the hypervisor software is the operating system. In other words, the hypervisor has direct access to the hardware without any other software interfering.
  • Type I Hypervisor is best for enterprise computing and large scale deployments.
  • Examples: VMware ESXi, Citrix XenServer and Microsoft Hyper-V hypervisor. 

In AdditionType 1 is widely recognized as the highest performing and most efficient super monitor for business computing. The ability to directly allocate resources makes these monitors more scalable.

Advantages of Type I Hypervisor are:

  • Physical resource optimisation: Organisations often spend money quickly by buying separate servers for different applications – a business that takes time and space in the data centre. With Type 1 hypervisor, IT can leverage server hardware, freeing up data centre and real estate costs, and reducing power consumption.
  • Better resource allocation: Most Type 1 monitors give administrators the ability to manually set resource allocations, based on application priority. Many Type 1 monitors also automate resource allocation as needed, allowing resource management to be a dynamic and personalised option.

TYPE II HYPERVISOR:

  • Type II hypervisors are embedded or hosted hypervisors.
  • Usually, these hypervisors are on top of the operating system. Due to its reliance on the underlying host operating system – unlike type 1 – it is known as “hosted hypervisor”.
  • Hypervisor runs as an application in the operating system, then runs directly on the host computer.
  • Type 2 hypervisor supports multiple clients but is not a direct access to the server hardware and its resources.
  • The pre-existing operating system processes calls to the CPU to obtain memory, network resources, and memory. All of these can create some latency.
  • Examples: Oracle Solaris Zones, Oracle VM Server for x86, Oracle VM Virtual Box, VMWare Workstation, VMware Fusion and more.

Advantages of type II Hypervisor are:

  • Easier configuration: These hypervisors are easier to configure and manage as there is an underlying operating system to work with.
  • Simplified management: Type 2 supervisors do not require a dedicated administrator.
  • Compatibility: Type 2 hypervisors are compatible with a wider range of hardware because they run on an operating system, rather than specific hardware machines.

KVM HYPERVISOR:

KVM stands for Kernel-based Virtual Machine It is a mixture of Type I and Type 2 hypervisors. It is on Linux and makes Linux a Type I hypervisor. This type of hypervisor:

  • is secure.
  • Offers plenty of storage
  • Full hardware support and memory management capabilities
  • Provides low latency
  • Allow apps to take priority
  • Provides better scalability, planning, and control of resources

COMPARISON BETWEEN HYPERVISOR AND DOCKER

The software that supports virtual machine creation in which a virtual platform is provided for the operating system to manage and run virtual machines is called Hypervisor, also known as Virtual Machine Monitor or Emulator or Virtualisation. Moreover, A system can control many virtual machines, helping to manage the operation of virtual machines through the hypervisor.
Docker is a virtualization service used in operating systems, where software is distributed in a container with software, libraries, and configuration files. Furthermore Written in the Go language and developed by Solomon Hykes, applications are created and deployed using containers and are developed as packages inside containers.

Comparison

  • Functioning Mechanism

The most significant difference between hypervisors and Dockers is how they start and use resources.

There are two types of hypervisors: the bare metal runs directly on the hardware while the second type runs on the operating system.

Docker, on the other hand, runs on the host kernel itself. Therefore, it does not allow users to create multiple versions of the operating system. Instead, they create containers that act as virtual application environments that users can work on.

  • Number of Application Instances Supported

A hypervisor allows users to build multiple versions of a complete operating system.

Dockers can run multiple applications or instances of the same application. It does this with containers.

  • Memory Requirement

The hypervisor allows users to run multiple instances of the entire operating system. This makes them resource-intensive. However They need dedicated resources for any of the shared hardware that the hypervisor allocates at startup time.

Dockworkers, however, have no such requirement. You can create as many containers as you need.
Depending on application requirements and available processing capabilities, Docker provides it for containers.

  • Boot-Time

Since Dockers do not require such resource allocation to create containers, they can be on the fly, to begin with. Above all one of the main reasons Dockers and Containers are growing in use is their ability to start-up in seconds.
After that, It may take up to a minute for the hypervisor to start up and function Docker can create containers in seconds and users can start quickly.

  • OS Support

The hypervisor is independent of the operating system. They can run on Windows, Mac, and Linux.

Dockers, on the other hand, is to Linux only. However, this shouldn’t be a deterrent to Dockers as Linux is a strong ecosystem.

REFERENCES:

https://www.vmware.com/topics/glossary/content/hypervisor.html

https://www.educba.com/hypervisor-vs-docker/

Written by 

Deeksha Tripathi is a Software Intern at Knoldus Inc Software. She has a keen interest toward learning new technologies. Her practice area is Devops. When not working, she will be busy in listening music , and spending time with her family .