Before virtualization and hypervisors, most computers could only run one operating system at a time. This means that you would have to pick between Linux, Windows, Mac, or a server-side operating system that you wanted to run on a computer.
Then hypervisors came in and changed everything. Hypervisors allow you to manage virtual machines, which are like computers within a computer.
In this guide, we’re going to talk about what hypervisors are, how they work, and why they are used.
What is Virtualization?
Virtualization is a technology that allows you to create virtual computers. These are computers that can share the same physical resources – CPU, memory – and are run on another computer. Virtualization is what allows you to set up both a Linux server and a Windows server on the same computer, for example.
Virtualization helps businesses scale their computation resources. This is because businesses do not have to worry about buying new hardware to run separate operating systems; they can run new computers within existing ones, and let them share their resources.
Without hypervisors, virtualization would not be possible.
What is a Hypervisor?
A hypervisor is a software layer that creates, runs, and monitors virtual machines.
Whereas virtualization refers to all of the tools that allow you to run a computer within a computer, the hypervisor has a very specific purpose. It manages virtual machines and ensures that each machine is kept separate.
A hypervisor, which is sometimes called a Virtual Machine Monitor (VMM), will assign each virtual machine its own segment of computing power and storage. This ensures that if you’re running multiple virtual machines they will not overlap.
This is a crucial feature because it means that if something goes wrong in one virtual machine, it will not affect any others, or the underlying system on which the virtual machine is hosted. For instance, if there was a security problem on one system, it would be isolated to that one system.
Hypervisors were invented by IBM in the 1960s for its mainframe computers. Today, they are used by businesses and individuals around the world to emulate Linux kernels, Windows, macOS, and other types of operating systems.
How do Hypervisors Work?
There are two categories of hypervisors: Type 1 and Type 2. Each of these categories have their own benefits and drawbacks, and are used in different situations.
Type 1 Hypervisors
A Type 1 hypervisor is run directly on the hardware of the computer that is hosting the machine. This is called the “physical host computer”. The Type 1 hypervisor will interact with a computer’s storage, memory, and other physical resources.
You’ll often hear this type of hypervisor referred to as a “bare-metal” or “native” hypervisor. This is because it has a direct relationship with the computer hardware. This relationship is beneficial because it means that this type of hypervisors are very efficient; there are no layers of abstraction between the physical hardware and the virtual machine.
Type 2 Hypervisors
A Type 2 hypervisor runs within an application on a host machine. Type 2 hypervisors are mostly used by individual computer users who want to run multiple operating systems. They are not practical for server-based environments because they don’t have direct access to the underlying hardware of a host computer.
Type 2 hypervisors are what tools such as VMWare Workstation and VirtualBox are considered to be. This is because they run as applications on a system. These tools do all the work necessary to allow you to run multiple virtual machines on one computer.
This type of hypervisor is useful because it makes it easy to set up an alternative operating system on an existing computer. However, Type 2 hypervisors have access to a physical machine, which can introduce security risks.
When are Hypervisors Used?
Hypervisors are commonly used in malware analysis, desktop virtualization, and server consolidation. While hypervisor software is mainly used within companies, some individuals use hypervisors to run alternative operating systems on their home computer.
Here’s a breakdown of the top use cases for hypervisors:
Server Consolidation
Hypervisors allow you to track the performance of each virtual machine. This makes it easy to see how multiple servers are performing at the same time, even if they are running different operating systems.
It is usually very difficult to track multiple machines with different operating systems because most of the time there will be separate tools that you need to run on each machine.
Desktop Virtualization
Not all software is built for every computing platform. Some software is only available on certain Linux distributions; other pieces of software are only available on Windows devices.
Hypervisors are commonly used by individuals and businesses to run virtual machines on their computers. This means that they can set up an instance of a particular operating system that they can then use to execute the applications that they need to run.
Malware Analysis
Virtual machines, to a great extent, are independent from their host machines. This makes them practical for malware analysis. Malware analysts use virtual machines to test malware, observe the behavior of malware, and diagnose its core features.
Analysts can use virtual machines to reverse-engineer a virus, worm, or other security threat without having to worry about their main computer being affected. Malware cannot escape from a virtual machine if it is configured correctly.
Conclusion
Hypervisors are used to manage virtual machines. They track the performance of each virtual machine, delegate system resources to those machines. They also ensure that each machine is independent from others that exist on the same machine.
Hypervisors have become an essential part of cloud computing. Without them, virtualization software would not be possible.
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Now you’re ready to start talking about hypervisors like a cloud computing expert!
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