Whiteboard Wednesday Episode 14: What is Virtualisation? Virtual Machines, Hypervisors and Hosts explained
Whiteboard Wednesday is me, a whiteboard and learning about all things IT Asset Management (ITAM), every Wednesday!
This week, Virtualisation – What are virtual machines. hypervisors and hosts and why are they important for IT Asset Management?
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So, let’s say that you have two systems in your company, one called payroll and one called accounts. And these are two applications sitting on two different machines. They are physical machines in your office that collect dust, with flashing lights, and you can see them.
What we can do is virtualise them and to virtualise them, you take these two systems, and you put them on one big box. Now, this is one system, but they operate completely separately. So this might be Linux, and that might be Microsoft, and you can switch this one off. It can be on a different version to that one. They are completely different entities, but they are run virtually on top of a physical machine.
So why do people virtualise? Well, as well as only using one machine rather than two, you can also dynamically exchange the resources. So you can say actually, payroll time, we’re going to use this much of the device. And when we’re doing the accounting system at year ends we can shift resources this side. So this is a dynamic use of resources, it’s a great concept, great use of computing.
In terms of terminology, this is a virtual machine. It’s a virtual piece of hardware. This is what you would call the physical host. And this layer is the virtualization layer. And the system running the virtual machines is called the hypervisor. The hypervisor is like the brains of the system, it allocates the resources, and provisions the different virtual machines.
Now, why is all of this important to it asset management? because this represents three IT assets. Two virtual and one physical. And as IT asset managers, we need to know in the relationship between the virtual and the physical, because the licensing terms and the cost of these assets will typically be determined by the underlying hardware, and what’s going on inside these virtual systems.
So we need to know about these relationships in order to be able to manage them.
Now, virtualization is not a new technique. IT departments have been virtualising their system for decades, but it’s still common in use in it departments today.
And more importantly, in order to understand cloud, you need to understand virtualization, because many of these techniques are now used in the cloud. So these two virtual systems are sat on hardware, but in the cloud that also might be virtual, which is another thing to get your head around in future videos.