Virtualization Explained

Hello everyone, in this video we're going to be  talking about virtualization. Now virtualization in computing is the process of simulating  hardware and software, such as computers, operating systems, storage, and networking. And  it does it in a virtual or software environment.

Now the traditional way a business operates  is by having one machine for one application. So for example let's say that a business has  three servers. And they would have one of those servers dedicated to running an email service  and that server has Microsoft Windows as its operating system.

And then that business would  have another server that's used for running a website and it would have Linux as its operating  system. And then they would have another server that's running a database and it's using Unix  as its operating system. So one machine with one application.

And in addition, those three servers  are running three different operating systems. But instead of having three servers running one  application each, what if just one server could do the job just as good and do it more efficiently.  So basically one server would take the place of the three and run all the applications and  even run their different operating systems.

So this is what virtualization does. Virtualization  is basically consolidating all of these physical servers with their different operating systems  and applications and running them on just one physical server in a virtual environment. So now  this one server is running three VMs or virtual machines.

It's running all of the different  applications such as email, web services, and databases. And they're all running side by side on  one machine. But not only the applications, but it's also running the different operating systems side  by side and it's doing this all by using software and it does it so well that when users interact  with a virtual server they would interact the same way as if they were still on multiple physical  servers.

They won't be able to tell the difference. Now the software that creates and runs the  virtualization is called a hypervisor A hypervisor is what allows one machine to run  multiple virtual machines. It allocates and controls the sharing of a machine's resources  such as storage space, RAM, CPUs, and so on.

Hypervisors come in two different types. There's  type 1 and type 2. A type 1 hypervisor is installed on bare metal hardware.

Meaning that there is no  existing operating system or any other software on the machine. The hypervisor is installed on  empty, bare metal hardware. A type 2 hypervisor is installed and runs on top of an existing  operating system, such as Microsoft Windows, MAC OS, Linux, Unix, and so on.

So the operating system sits in between the machine and the hypervisor. So as an example, let's go ahead and install  a type 1 hypervisor on a machine. So let's go ahead and build our server that's going to be  used to create virtual machines.

So we'll start out with a server case and then we'll install  hardware in it, such as a motherboard, CPUs, RAM, and storage drives. So now our server hardware  is built. So the next step is to install a type 1 hypervisor and a common one is VMware ESXi. 

And that's going to be installed right on top of our bare metal server. So remember there's no  operating system installed on this server, it's empty. And then once the hypervisor is installed  it will be used to create virtual machines.

So for example we'll go ahead and create three  virtual machines. So first we have to allocate the server's hardware resources to each VM,  such as how many CPUs, how much RAM, how much storage space, and so on. And then once that is  complete we can load our different operating systems in each VM, such as Windows, Linux, and  Unix.

And then we'll install whatever service and application that each VM is going to run,  such as email, a web server, and a database. And that's pretty much it. So these three virtual  machines are basically three software-based computers.

They all run just like a regular  computer. They all have their own operating system software, applications, and allocated  hardware. And each VM is independent of the other.

So this was an example of a type 1 hypervisor.  Type 1 hypervisors are the most common because they are used in enterprise data centers.  Some examples of type 1 hypervisors are VMware ESXi which I mentioned previously,  Citrix XenServer, and Microsoft Hyper-V.

And as I mentioned earlier, a type 2 hypervisor  is installed and runs on top of an existing operating system. These are typically used on  personal computers. For example, people will use a type 2 hypervisor on their computer  if they want to test out new software for research purposes or to try out and test  different operating systems.

For example this MAC is running two VMs. One is Microsoft  Windows and the other is Linux. Some examples of type 2 hypervisors are Oracle VM Virtualbox,  Microsoft Virtual PC, and VMware Workstation.

So what are the benefits of virtualization? Well  the first benefit is that it saves money on hardware and electricity because a business  won't need as many physical machines or the power that it takes to run those machines. It can  just create virtual machines instead.

And second it saves money on floor space. A business won't need  to purchase a lot of floor space to accommodate a large number of machines. Another reason is  maintenance and management.

Because by having physical machines it requires administrators to  maintain and manage a machine in case something happens. Such as a change in the configuration,  or equipment failure, or maybe even a fire! And another reason is portability.

VMs on a  physical machine can easily be transferred to another physical machine if needed. So for  example if the current machine that is running the virtual machines is old and outdated, or if  it's running out of space, those VMs can easily be transferred to a new and more powerful machine  very rapidly, which makes things very convenient. Another benefit of virtualization is that  it takes advantage of the full computing capability of a machine.

And this is because  today computers and servers are so powerful that most of the time their full potential is  not being used. The software applications that they are running are not able to utilize the  machine's full potential. So the majority of the machine's power is not being used.

But with  virtualization, it can create virtual machines. So it can push a machine's capacity to its limit  and take full advantage of a machine's capability. And another reason is disaster and recovery. 

Virtual machines are just software files and those files can be backed up and they can be  uploaded to multiple physical machines. So if a machine goes down, the other machines will be  there to take over. So I want to thank everyone for watching this video on virtualization.

Please  subscribe and I will see you in the next video.