Cloud Hosting Glossary

Hypervisor

A hypervisor or virtual machine monitor (VMM) is the essence of virtualization. It permits a number of operating systems (OS) to be run on a physical host computer, and each one has a separated virtual environment. Visualize it like a virtual landlord segmenting a building (your machine) into some independent flats (virtual machines) where every single one of them is a tenant of a standalone isolated individual (OS and software). Hypervisors do this by controlling the hardware and assigning to each OS what it requires without interrupting others.

Types of Hypervisors

Type 1: Bare-Metal Hypervisor: It is a hypervisor that directly executes on the host machine hardware with no operating system in between. It is very efficient and secure and is widely used in enterprise data centers. VMware ESXi, Microsoft Hyper-V, and Xen are examples.

Use Case: Cloud providers such as Amazon Web Services (AWS) utilize Type 1 hypervisors to host scalable virtual servers.

Type 2: Hosted Hypervisor: This is executed on top of a previously installed operating system. It suits personal or development purposes rather than general deployment. Examples include Oracle VirtualBox and VMware Workstation.

Use Case: Hypervisors Type 2 are employed by software engineers to perform application testing for diverse operating systems on a single machine.

Significance of Hypervisors

Optimization of Resources: Hypervisors permit multiple VMs to run on a single piece of hardware, leveraging maximum hardware and reducing expense. Multiple OS environments can be run cost- and time-efficiently with one physical server.

Isolation and Security: Individual VMs are segregated. If a single VM gets compromised or hangs, it does not affect the other VMs. Such containment is most essential when maximum security and fault tolerance must be ensured.

Scalability and Flexibility: Virtual machines can be added, removed, or upgraded without necessitating any physical change in the system. This makes hypervisors hugely valuable in cloud computing if the resources are to be dynamically changed.

Testing and Development: Developers employ hypervisors so that they can build test environments without worrying about effects on their main system. It is also more convenient when installing ancient software that operates on ancient operating systems.

Disaster Recovery: Since virtual machines are simply files, they can be replicated, copied, or moved from system to system. If a system fails, it is faster and easier to restore a VM than to re-wire hardware.

Real-World Example

A software company is coding an application that will be run on Linux, Windows, and macOS. Instead of purchasing several machines, the coders use a hypervisor like VirtualBox to install three virtual machines in one laptop, each virtual machine a different OS. Not only is this hardware cost-effective, but it makes cross-platform testing easy.