A Cloud Hypervisor is software that enables the sharing of cloud provider’s physical compute and memory resources across multiple virtual machines (VMs). Originally created for mainframe computers in the 1960s, hypervisors gained wide popularity with the introduction of VMware for industry standard servers in the 1990s, enabling a single physical server to independently run multiple guest VMs each with their own operating systems (OSs) that are logically separate from each other. In this manner, problems or crashes in one guest VM have no effect on the other guest VMs, OSs, or the applications running on them.
Although there are multiple types of VMs, they all perform the same task, enabling a single set of physical server hardware (including CPU, memory, storage, and peripherals) and enabling the simultaneous use by multiple instances of OSs, whether Windows, Linux, or both.
Role of Hypervisor in Cloud Computing
Hypervisor is the single, most advanced technology that is able to handle all the resources effectively in cloud computing. The use of hypervisors in cloud emerges from the fact that it is able to meticulously dole out CPU resources from one cloud account to another.
In layman’s terms, all the cloud terminals are but virtual machines. When you opt for a cloud server, you are allocated resource from the giant resource pool. Now, since all the cloud servers are to be independent of each other, the resources are to be distributed in a discreet manner.
Despite being in the same pool, the cloud servers are never aware of each other’s existence. Or, even if they are, they never seem to interfere.
How Does a Hypervisor Work?
Hypervisors and collections of virtual machines are used for numerous different tasks in a business setting, including data replication, server consolidation, desktop virtualization, and cloud computing.
Typically, when you want to replicate a virtual machine, you have to replicate its entire volume manually. Using a hypervisor, you can simply choose which virtual machines and parts you want replicated, and it will perform the process for you.
If you have a business with multiple servers operating different services for customers over the internet, it can become difficult to centrally manage them all, especially if they run different operating systems. A hypervisor lets you virtualize these servers, then manage them all in one physical machine, so they operate more efficiently. Simply put, you can allocate resources to all the machines, which can, in turn, make better use of the total physical resources you have available, rather than having physical resources sitting idle while they aren’t in use.
Desktop virtualization is useful when you want to use a piece of software compatible with one operating system, such as Windows, but you have another operating system, such as Linux or Mac OS, on your machine. With a hypervisor, you can set up a Windows virtual machine to run the software without having to change operating systems.
There are two types of hypervisors:
- Type-1, native or bare-metal hypervisors
Type-2 or hosted hypervisors
Type-1, Native or Bare-Metal Hypervisors
These 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.
This type of hypervisor is most common in an enterprise data center or other server-based environments.
KVM, Microsoft Hyper-V, and VMware vSphere are examples of a type 1 hypervisor.
Type-2 or Hosted Hypervisors
These hypervisors run on a conventional operating system (OS) just as other computer programs do. A guest operating system runs as a process on the host. Type-2 hypervisors abstract guest operating systems from the host operating system.
A type 2 hypervisor is better for individual users who want to run multiple operating systems on a personal computer.
VMware Workstation and Oracle VirtualBox are examples of a type 2 hypervisor.
Even inexpensive desktops and laptops feature multi-core CPUs, so it’s easy to see why hypervisors have become more popular. In addition to faster CPUs with more physical cores and multi-threading support, the availability and affordability of modern high-speed SSD (Solid State Drive) storage and speedier PCIe lanes also play an essential role in hypervisor performance.
Hypervisors will likely find their way to even more applications and platforms as technology expands. The demand for cloud services remains robust, the hardware is evolving to offer even more opportunities for cloud deployment, and software engineers worldwide are working tirelessly to keep up with demand and harness even more power and efficiency from cloud-based systems. The sooner we understand the need and benefits of hypervisors, the better off we will all be.