What Is A Hypervisor, Its Types And Use Cases?
If you are interested in cloud computing, virtualization, or simply getting the most out of your hardware, you might have heard of the term “hypervisor”. But what exactly is a hypervisor and how does it work? In this article, we will explain the basics of hypervisors, their types, benefits, and use cases.
What is a Hypervisor?
A hypervisor is a software process that creates and runs virtual machines (VMs) and allocates the host server’s compute, storage, and networking resources as needed by each VM. A virtual machine is a simulated computer system that can run its own operating system and applications, independent of the underlying hardware.
A hypervisor allows you to access several virtual machines that are all working optimally on a single piece of computer hardware.
A hypervisor is sometimes also called a virtual machine monitor (VMM) or virtualizer. The term hypervisor is a variant of supervisor, a traditional term for the kernel of an operating system: the hypervisor is the supervisor of the supervisors, with hyper- used as a stronger variant of super-.
Types of Hypervisors
There are two main types of hypervisors: type-1 and type-2.
Type-1 Hypervisors
Type-1 hypervisors, also known as native or bare-metal hypervisors, run directly on the host’s hardware to control the hardware and to manage guest operating systems. For this reason, they are sometimes called bare-metal hypervisors.
Type-1 hypervisors are more efficient and secure, as they have direct access to the hardware and do not depend on another operating system. However, they are also more complex and require specific hardware support.
Some examples of type-1 hypervisors are VMware ESXi, Microsoft Hyper-V, and Citrix XenServer.
Type-2 Hypervisors
Type-2 hypervisors, also known as hosted hypervisors, run on a conventional operating system (OS) just as other computer programs do. A virtual machine monitor runs as a process on the host.
Type-2 hypervisors abstract guest operating systems from the host operating system. Type-2 hypervisors are more flexible and portable, as they can run on any hardware that supports the host operating system.
However, they are also less performant and secure, as they have to share the hardware resources with the host operating system and other applications. Some examples of type-2 hypervisors are VMware Workstation, Oracle VirtualBox, and Parallels Desktop.
Benefits of Hypervisors
Hypervisors play an essential role in enabling server virtualization, which is itself essential to enabling cloud computing.
Some of the benefits of hypervisors are:
Resource optimization: Hypervisors allow you to run multiple virtual machines on a single physical server, reducing the cost and space of hardware, power, and cooling. Hypervisors can also dynamically allocate and balance the resources among the virtual machines, ensuring optimal performance and availability.
Isolation and security: Hypervisors isolate each virtual machine from the others, preventing interference and improving security. Hypervisors can also enforce policies and controls on the virtual machines, such as encryption, backup, and firewall.
Flexibility and scalability: Hypervisors enable you to run different operating systems and applications on the same hardware, increasing the compatibility and diversity of your IT environment.
Hypervisors can also easily create, clone, migrate, and delete virtual machines, allowing you to scale up or down your capacity as needed.
Testing and development: Hypervisors provide a convenient and safe way to test and develop new software, as you can run multiple versions and configurations of the software on different virtual machines, without affecting the production environment.
Hypervisors can also facilitate the deployment and integration of the software, as you can easily move the virtual machines across different servers or clouds.
Use Cases of Hypervisors
Hypervisors have a wide range of use cases in various domains and scenarios, such as:
Cloud computing
Hypervisors are the backbone of cloud computing, as they enable the creation and delivery of cloud services, such as infrastructure as a service (IaaS), platform as a service (PaaS), and software as a service (SaaS).
Cloud providers use hypervisors to offer their customers virtualized resources, such as servers, storage, and networks, on demand and at scale.
Cloud customers use hypervisors to access and manage their cloud resources, such as applications, data, and analytics, from anywhere and at any time.
Data centers
Hypervisors are the key to modernizing and optimizing data centers, as they enable the consolidation and automation of data center operations.
Data center operators use hypervisors to reduce the number and complexity of physical servers, improve the utilization and efficiency of resources, and enhance the reliability and availability of services.
Data center users use hypervisors to access and manage their data center resources, such as databases, web servers, and applications, from a single interface and with minimal downtime.
Desktop virtualization
Hypervisors are the foundation of desktop virtualization, as they enable the delivery and consumption of desktops as a service (DaaS). Desktop virtualization providers use hypervisors to offer their customers virtualized desktops, which are hosted and managed on a remote server, instead of on a local device.
Desktop virtualization customers use hypervisors to access and use their virtualized desktops, which can run any operating system and application, from any device and location.
Education and training
Hypervisors are the tool of choice for education and training, as they enable the creation and provision of virtual learning environments (VLEs). Educators and trainers use hypervisors to create and customize virtual machines, which can run any software and content, for their students and trainees.
Students and trainees use hypervisors to access and interact with their virtual machines, which can simulate any scenario and situation, from any device and location.
How Hypervisor Started
The concept of hypervisor can be traced back to the 1960s, when IBM developed the first systems that supported virtualization. The motivation was to enable the migration of bank transaction services without interrupting the service.
IBM created a test tool called SIMMON and a one-off research system called CP-40, which began production use in January 1967 and became the first version of the IBM CP/CMS operating system. CP-40 ran on a modified S/360-40 machine that supported dynamic address translation, a feature that enabled virtualization.
The term hypervisor was coined by IBM around 1970 for the 360/65 machine and later used for the DIAG handler of CP-67. The term is a variant of supervisor, a traditional term for the kernel of an operating system.
The hypervisor is the supervisor of the supervisors, with hyper- used as a stronger variant of super-.
The CP/CMS system was based on a virtual machine monitor or hypervisor that ran on the hardware and created several virtual machines. Each virtual machine could run its own operating system and applications, independent of the others.
The CP/CMS system was the predecessor of IBM’s VM family of virtual machine operating systems, which are still in use today.
The first hypervisors were type-1 or native hypervisors, which ran directly on the host’s hardware to control the hardware and manage the guest operating systems.
Later, type-2 or hosted hypervisors emerged, which ran on a conventional operating system as a software process and abstracted the guest operating systems from the host operating system.
Hypervisors have evolved over the years to support different types of hardware, operating systems, and applications. They have also become more efficient, secure, and flexible, enabling various use cases such as cloud computing, data centers, desktop virtualization, and education and training.
Hypervisors are the future of computing, as they enable you to leverage the full potential of your hardware and software.
Conclusion
Hypervisors are a powerful and versatile technology that enable you to create and run virtual machines on a single piece of hardware. Hypervisors have many benefits, such as resource optimization, isolation and security, flexibility and scalability, and testing and development.
Hypervisors have many use cases, such as cloud computing, data centers, desktop virtualization, and education and training. Hypervisors are the future of computing, as they enable you to leverage the full potential of your hardware and software.
