Hypervisors are software that creates and runs virtual machines (VMs). The beauty of using a hypervisor is that it can be installed on just about any size of system, from a single-user machine to a server farm running dozens of machines. The hypervisor acts as an intermediary between the VM and the operating system, so you can run many VMs simultaneously.
The idea of pure hardware virtualization comes from Intel, which patented the concept in 1990.
The term “hypervisor” itself was introduced by IBM in 2000 although their VTAM did it already in 1974. It offered features very similar to today’s virtual machines.
The hypervisor sits directly on the hardware, just below the operating system of the host machine, and is responsible for the creation, execution, management, and allocation of partitions of the hardware.
The hypervisor allows building virtual environments or virtual machines on top of the underlying hardware.
Hypervisors can be standalone (meaning they don’t require an additional operating system) or they can be hosted (meaning they run on top of an operating system). If a hypervisor is standalone it means it doesn’t need another operating system to run.
Why use a hypervisor?
Virtual Machines (VMs) offer a way to make use of systems’ available resources and mobility for IT administrators. Hypervisors make it possible to use more of a system’s available resources and provide greater IT mobility since the guest VMs are independent of the host hardware. This means they can be easily moved between different servers.
A hypervisor reduces the space, energy, and maintenance requirements. Multiple virtual machines can run off of one physical server with a hypervisor, leading to less space, energy, and maintenance requirements.
According to Wired, “[a]ny company that has computers on the go — the financial industry, for example — could save by using a hypervisor.”
Types of hypervisors
There are various types of hypervisors. A Type 1 hypervisor has the power to manage other operating systems. These hypervisors are often found in servers and they usually need a bare metal. In contrast, a Type 2 hypervisor runs on top of another operating system. These hypervisors can be found on most home computers.
Bare-metal hypervisors are also known as native hypervisors because they run directly on the physical hardware. These hypervisors are free of the application layer, making them the fastest and most lightweight of all possible hypervisors. They also offer the most direct access to system hardware, which provides an environment that is more familiar to developers.
However, bare-metal hypervisors do not provide any form of abstraction and limit the number of virtual machines that an organization can operate. But when the benefits outweigh the limitations, then all other types of hypervisors pale in comparison.
Hosted hypervisors run on top of the operating system (OS) of the host machine. Although hosted hypervisors run within the OS, additional (and different) operating systems can be installed on top of the hypervisor.
Hosted hypervisors run within the host machine’s operating system and allow you to create an entire virtual machine from the ground up. This provides a couple of different advantages. First, you can download new operating systems from the VMWare website and install them as a virtual machine. However, the only downside is that hosted hypervisors do not support as many virtual machine resources as a non-hosted hypervisor, which the latter is more expensive.
Some of the benefits of a hosted hypervisor include reduced cost, hardware compatibility, and greater software compatibility. Hosted hypervisors run within the OS, but additional (and different) operating systems can be installed on top of the hypervisor.
What is a cloud hypervisor?
A cloud hypervisor is a type of virtual machine manager that enables you to create, run, and maintain virtual machines on a cloud-based platform that is hosted by a central server. Cloud-based applications are hosted on servers that are maintained, powered, and operated by the cloud service platform provider. The cloud service platform provider generally charges a fee for hosting the cloud-based applications of its users on its servers.
The cloud service platform provider typically charges a fee for hosting the cloud-based applications of its users on its servers.
For instance, a cloud hypervisor can support multiple operating systems and workloads in a safe and effective way, thereby increasing the efficiency and performance of the IT system.
How does a hypervisor work?
The hypervisor has the main role of managing the resources of a physical machine and to allow multiple virtual machines to run simultaneously on it. Multiple versions of virtual machines (also called guest operating system and software applications) can run on a single physical machine (host operating system and hardware platform) using either of two methods: Simultaneous multithreading (SMT) and dynamic time-sharing (DTS).
With SMT, processors appear as logical processors (threads) of the virtual machine. With DTS, the hosting operating system provides each virtual machine with a time slice on each physical processor. While the hypervisor typically runs directly on the hardware, it also supports running on a virtual machine on top of a host operating system.
What are the benefits of hypervisors?
The benefits of using a hypervisor to host multiple virtual machines are numerous. First, it significantly reduces hardware costs, which is great for smaller budget operations or organizations that are trying to reduce the salary outlays. Second, it’s easier to maintain operations. This is because you can use your local hardware for operations, instead of relying on the hardware that the hosting company provides. And third, this can be a way of reducing downtime, as your virtual machines can be restarted during the peak hours of the day, and then shutdown and restarted when there’s less traffic on the network.
- Virtualization allows for increased efficiency, easy upgrades, and increased availability.
- Virtualization is a process that allows one physical server to host many other servers, called virtual machines. It helps to increase efficiency by running multiple virtual machines on one physical server. That way, the physical server only needs to spend its resources on one task instead of many.
- This also means that when one virtual machine goes down, the other virtual machines on the server are able to continue working. This increases availability.
- Additionally, virtualized servers are much easier to upgrade because the operating system only has to be upgraded in one location. If a virtual machine is no longer needed, it is as simple as terminating it within seconds.
