There are 7 primary types of virtualization, Hypervisor being the topic of this article.
We'll start by taking a look at what a server looks like without Virtualization.
We'll start by taking a look at what a server looks like without virtualization. In this example, our server is working with the physical hardware that it has, it's running a Windows OS that is serving a website over HTTP. As simple as this configuration might be we can run to some limitations along the way:
- our OS is tied to hardware, which means it is not portable and we can't easily move that OS and the application that is installed on it to another piece of hardware if we have some sort of issue or if wanted to upgrade the specs due to more/less traffic.
- the hardware might be underutilized because of the wrong estimation of what we need and in the context of cloud computing, this will cause a higher bill.
this layer is able to present virtualized hardware to the operating system, in that case, we call it a virtual machine or VM for short. The VM has an allocation of resources, maybe the server has 32GB of RAM but we just give 8GB the VM, also a certain amount of CPU power, disk space, and an allocation of shared networking... There is no physical hardware here it's virtualized and presented by the hypervisor but the OS doesn't know that, it just sees hardware.
the cool part about this is being able to run multiple VMs on the same physical hardware, another benefit is that any instance of these VMs can easily be moved to another server if it failed, went down, or if you wanted to perform some upgrades on hardware.