Virtualization technology makes it possible to separate hardware resources like CPU and storage from physical computers. Most famously, it’s the foundation of cloud computing. Hypervisors play a key role in the process of virtualization. The following article explores hypervisor use cases, types, benefits, and disadvantages.
What is a hypervisor?
A hypervisor is a software that creates and runs virtual machines (VMs), which are software emulations of a computing hardware environment. Sometimes called a virtual machine monitor (VMM), the hypervisor isolates the operating system and computing resources from the virtual machines and enables the creation and management of those VMs. These virtual machines – simply, code operating in a server’s memory space – enables administrators to have a dedicated machine for every service they need to run.
This small software layer is the most important component of virtualization technology, which comprises storage, desktop, operating system (OS), and application virtualization. Hypervisors also make server virtualization possible by allowing different operating systems to run separate applications on a single server while still using the same physical hardware resources. Virtualization is the basis of modern cloud computing, enabling scalability, security, and management of global IT infrastructure.
Role of Hypervisor in Cloud Computing
The hypervisor is the single, most advanced technology that is able to handle all the resources effectively in cloud computing. The use of hypervisors in the 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 cloud terminals are virtual machines. When you opt for a cloud server, you are allocated resources 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 it 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 to be 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.
Why Use a Hypervisor?
From a VM’s standpoint, there is no difference between the physical and virtualized environment. Guest machines do not know that the hypervisor created them in a virtual environment or that they share available computing power.
The fact that the hypervisor allows VMs to function as typical computing instances makes the hypervisor useful for companies planning to:
- Maximize utilization of their computing resources. Multiple virtual environments on a single server fully utilize the available CPU and memory.
- Provide better IT mobility. The VMs do not depend on their host hardware and can easily be transferred to another system.
Benefits of hypervisors
There are several benefits to using a hypervisor that hosts multiple virtual machines:
- Speed: Hypervisors allow virtual machines to be created instantly, unlike bare-metal servers. This makes it easier to provision resources as needed for dynamic workloads.
- Efficiency: Hypervisors that run several virtual machines on one physical machine’s resources also allow for more efficient utilization of one physical server. It is more cost- and energy-efficient to run several virtual machines on one physical machine than to run multiple underutilized physical machines for the same task.
- Flexibility: Bare-metal hypervisors allow operating systems and their associated applications to run on a variety of hardware types because the hypervisor separates the OS from the underlying hardware, so the software no longer relies on specific hardware devices or drivers.
- Portability: Hypervisors allow multiple operating systems to reside on the same physical server (host machine). Because the virtual machines that the hypervisor runs are independent of the physical machine, they are portable. IT teams can shift workloads and allocate networking, memory, storage, and processing resources across multiple servers as needed, moving from machine to machine or platform to platform. When an application needs more processing power, the virtualization software allows it to seamlessly access additional machines.
Types of hypervisors
Type 1 hypervisors, also known as native or bare metal hypervisors, run directly on the host machine, with no other software or operating system in between it and the hardware. A type 1 hypervisor acts as a basic OS itself, on which the VMs run. In this scenario, the host machine can be used for nothing else but operating the VMs.
This type is typically found in large-scale or enterprise deployments. Because they have direct hardware access and can directly assign resources, these bare-metal hypervisors are highly scalable, can optimize physical resources on the host server, and allow admins to set resource allocation manually.
Type 2 hypervisors, sometimes called embedded hypervisors or hosted hypervisors, run as an application within the operating system on the host hardware. This hypervisor type does support having multiple guest VMs run on the same host, but it cannot directly access the host hardware and resources. It is typically used in testing labs or home environments.
While type 2 hypervisors are typically easier to set up and manage than type 1 versions, they do have some latency and performance issues because the host OS still has to manage the physical hardware resources. They also come with some additional risk, because any system crashes or malware attacks on the host OS then affect the guest VMs as well.
The rise of the Internet of Things (IoT) has led to a third hypervisor type, the embedded hypervisor. This hypervisor type enables the virtualization of IoT devices, allowing for improved hardware use, enhanced security, and support for multiple OSes.
Choosing a Hypervisor
There are a few things to keep in mind when selecting a hypervisor.
- Needs. Understand the needs of every person who will be impacted. Take into consideration the scalability, usability, and reliability of the solution. Ensure that the product delivers enough performance for your company.
- Cost. Is the hypervisor built into a larger solution or does it come with licensing fees? Make sure you’re aware of exactly what you’re getting and at what cost.
- Ecosystem. Does the solution support the guest operating systems you use? Will the product require specialists to maintain and troubleshoot? Is there ample documentation and support?
Hypervisors have been around for a long time, but with the increased use of cloud computing their importance is becoming more apparent. Ensuring your hypervisor is set up correctly and functioning properly is vital for keeping your virtual machines running effectively, managing resource use, and maintaining device security. To do this, I recommend using a third-party monitoring tool like Virtualization Manager to get a complete picture of your VM performance.