What is Hyper-V in Windows Server 2019?
In the technology field, there is always the next hot thing that everybody starts talking about.
Virtualization was one of those topics when it first made its appearance. Microsoftís virtualization
product is called Hyper-V. Virtualization has enabled IT professionals to better use the resources
that have been purchased and has led to the creation of cloud computing services.
Introduction to virtualization
Every organization used to have physical servers. In most cases, they followed best practices and
one server was dedicated to one application. This often led to wasted resources because the application
didnít actually need all the central processing unit (CPU) and random access memory (RAM) it was given,
so those resources would sit idle. At the same time, the organization was paying for power and cooling
for a server that wasnít necessarily doing anything at the moment.
The amount of time it took to stand up a new server could be an issue for projects that were
time-sensitive. With each physical server, you had to rack it, cable it, configure it, and install
software on it. Provisioning new servers for large projects could take weeks to months, especially
if multiple teams were involved.
Virtualization was a game changer. Instead of buying individual smaller servers to run single
applications, an organization could purchase bigger, more powerful servers to run a hypervisor of
some kind that would, in turn, run multiple virtual servers, referred to as virtual machines (VMs).
By purchasing larger servers to run the smaller workloads, organizations were able to save on power
and cooling costs. They were also able to reduce the amount of time needed to go to market, because
the virtualization administrator was typically the one who would spin up the server operating system
in a VM, set up the networking, and perform the basic configuration tasks like assigning IP addresses
and other necessary steps.
Virtualization really streamlined the process for system administrators and organizations to be
able to build servers quickly in response to the needs of other teams for projects or for expanding
the existing capacity to support applications. It also simplified recovery efforts when configured
properly because VMs on a failed host could be transferred to another host.
You sometimes hear hypervisors referred to as hosts and virtual machines referred to as guests. If
you run into this terminology, donít let it confuse it. These terms are used across all types of
Type 1 and Type 2 hypervisors
Before diving into the difference between Type 1 and Type 2 hypervisors, make sure you understand
what a hypervisor is. The hypervisor is essentially a process that allows you to create, run, and manage VMs.
The hypervisor is ultimately responsible for presenting resources to the VMs that are running on
it, including CPU, RAM, networking, and storage.
Most of the hypervisors let you overprovision VMs, meaning that you can assign resources that are
not necessarily available. This may work for you if your workloads are very small, but if there
are spikes in the workloads, or if VMs take too many resources, then the hypervisor could become
starved for resources, which could impact all your VMs that are running on that hypervisor. Do not
over-provision your VMs.
Type 1 hypervisors
Type 1 hypervisors are also referred to as bare-metal hypervisors. This is because the software
for the hypervisor can run directly on the host systemís hardware. Type 1 hypervisors provide the
best performance and security of the hypervisors, but some of them are more complex that others to set up.
Here are some examples of the more common Type 1 hypervisors:
• Microsoft Hyper-V
• VMware ESXi
• Oracle VM Server
• Citrix XenServer