Hello, my awesome students.
A lot of you have asked me to go over some of the virtualization technology, like how the virtualization
works.
So I know a lot of you are starting Linux for the first time or even the I.T. or getting into the IETF
field for the first time.
And when you get into the Linux, you probably notice a lot of Linux servers actually run on the virtual
technology.
So what exactly is virtualization?
So I'm going to take some time off yours, and I'm going to try to try my best to explain you what virtualization
is.
So you will have a better understanding when someone is talking about virtualization.
What is virtual?
Something that is not physically existing, so you could say something if it's, let's say a computer
is a virtual, it means it's in reality you cannot really physically touch it.
It's virtual that is based that computer that is based on a software related type of computer.
So what is a virtualization technology?
Virtualization is the process of creating a software based or virtual representation of something such
as a virtual application, server, storage and network.
So again, the virtual technology.
Let me take a couple of steps back and I will tell you how people came up with virtualization.
So you have a physical machine, as you could see right now to additional server architecture right
here at the bottom, you have a physical machine.
You go to, for example, you go to a computer store, you buy your computer, then build that computer
if you have a pre installed operating system on it, right?
Maybe if you are buying a regular Dell or HP server, you probably going to see that it has a windows
installed on it.
And then when you have the windows installed, you actually run all the applications.
So what are the applications like Firefox, even Microsoft Office, word a calculator and all of those
are applications, right?
So now so let's say if your application, the only purpose of your computer is to run that application,
and that application is using only two gigabyte of memory.
So what happens if your computer has 16 gigabyte C++ remaining 12 gigabyte is useless, right?
So everybody got together and says, Hey, we got to do something about it.
We we are, we are wasting the resources.
So they came up with the idea, Hey, how about we dual partition the computer and we could put one
operating system at a time?
OK, perfect idea.
Everybody got together now.
The problem with that you could only run operating system one operating system at a time.
So still not an optimized way your you couldn't get the same results out of it as you wanted.
Then they got back again and they got back again together and said, What should we do to utilize that
remaining unused memory?
Then came the virtualization technology, the virtualization technology.
What happens here is you have a regular physical server, just like any other server, you install a
layer of virtualization layer on top, just like in this case, you would in the other case, the older
case you would install like a regular operating system.
But in this case, you would install an operating system that is a hypervisor that's called a hypervisor
layer on top of it.
Once you have the hypervisor layer on top of it, by the way, that's also software, then you could
run a multiple operating system at the same time.
So if your computer has, let's say, 16 gig of memory, then you tell me how many virtual machines
you can run.
If each virtual machine requires two gig eight right?
But I would say not really.
Eight.
But let's say a set of seven because you do want to give at least two or three gigs to your own machine.
The machine that is right here at the bottom right.
So that's how the virtualization technology works.
Again, to wrap it up, I am please pay close attention.
Virtualization is basically a machine that does not have a physical hardware underneath it, actually
using a software based computer processing and memory.
All right, so now let's talk about the companies that are offering virtualization products.
So if you wanted to get into it and you start looking for a job, it is important for you to know what
are the companies out there that are offering virtualization or have their product as a virtualization
product on the number one?
I would say the VMware, that's the one that came up with the virtualization technology, primarily
the beginning, and a lot of market share is actually used today by a VM where the next one is Microsoft.
Everybody knows Microsoft.
Their technology is called Hyper-V is a hypervisor that runs and allows you to run multiple operating
system.
Then we have Citrix.
RedHat also have a virtualization technology, as well as Oracle, Amazon, and I'm sure a lot of people
know Amazon a UX cloud.
You ever heard of it?
So yes, they do have a virtualization technology.
As well and also offer a huge platform, a cloud platform, then we also have Google and you probably
heard of Google Azure.
Sorry, Google, it's Microsoft is the Azure, which is the cloud technology.
So Google also have the virtualization technology.
IBM has it and Hawaii, Hawaii.
I hope I'm pronouncing it right.
So that's another company that actually offers virtualization technology.
All right.
Moving on some of the terms I think you should have really know because I don't want you to go out on
the field or go out for for the interview.
And some of the terms are being thrown at you.
And I don't want you to look at yourself and say, What exactly does it mean?
So let's take some time, and let's understand some of the terms that you should really know.
Regardless, if you are learning a Linux, Windows or whatever operating system you are learning, this
is something I.T. terminologies in terms of virtualisation hypervisor now any time when you run your
virtual machines on top of a server.
So the the underlying host that is allowing you to run those virtual machines that that software is
called hypervisor.
You need to remember when someone says hypervisor, it means not the virtual machine.
It's actually a machine that's running under it.
Or that that was the machine that supporting it.
That hypervisor is also referred as that host many times as referred as a host or virtual server.
So it's a interchangeably terms.
If someone says, Hey, virtual server it try to clarify if they are referring as a host or hypervisor
host.
When someone sees host, I was in nine out of 10 times.
People are referring to the actual hypervisor and then someone says, Hypervisor, then you know it
is an actual hypervisor moving on virtual machine.
Any virtual machine that you run on top of the hypervisor is called virtual machine.
It is also referred as guest operating system or insured VM.
Then, in order to manage the bunch of hypervisor together, you need a some kind of software and that
software is called of like a virtualization manager in VMware.
Its call center and Oracle virtualization platform is call or VM manager, then virtual desktop.
You heard of that as well.
If you are working for a company, you're probably given a virtual desktop.
It is basically and a VM as well, but it is given a name as a virtual desktop is because it is used
for your regular day to day work where you are given instead of a laptop, you're given a virtual desktop
where you will log in and do your regular day to day job.
And it is like your personal desktop kind of way.
It's not a server, it's a desktop P2P.
You probably going to hear the word P2P, which means physical to virtual.
The reason we have this term is used in many times.
It because a lot of companies who are still running on physical environment, they are moving from physical
to virtual.
They do why to save money.
They do want to go to physical.
They wanted to go to virtual.
So the term they use is if P2P.
So it's not O, it's actually number two.
So P2P, physical, virtual and there are many different software that are used to convert a physical
machine to a virtual machine like VMware has a software called VMware Converter that allows you to convert
a physical machine to a virtual machine.
By the way, before I get into the snapshot, there is also something called V2V, meaning virtual to
virtual.
So if you are running on VMware platform and you want to migrate to Oracle platform, then you use a
tool to migrate virtual machine to virtual machine.
Of course, that term exists like a virtual machine to physical machine.
Very rarely use, meaning the actual procedure is very rarely used.
I don't know why someone would want to move from virtual to physical.
The only reason I could think of.
If someone wants to move from virtual to physical is at one point and they move to virtual.
They weren't there.
They weren't getting the required resources or the application was not functioning properly.
So they decide to move back to physical.
That's when I could think that.
It would be the top.
All right.
Next one is snapshot, a snapshot is a term like when it's it's it's a technology that is used in virtualization
platform, which allows you to take a snapshot of your virtual machine.
Meaning if you if you if you click on your virtual machine and click on the option, take snapshot.
It will actually take the exact same set.
You are the exact same state off that virtual machine.
Kind of like backup, but it's not a backup.
So let's say if you if I take a snapshot of a virtual machine today or at this time and tomorrow I install
the software and my software crashes my entire machine.
Now I could come back and revert back to the today's snapshot.
That's the beauty of taking snapshots, and that's a beautiful technology, which I love in virtualization.
The next one is clone or cloning.
That's also another term that you're going to hear a lot of times when you are in virtual technology
world.
What it means is when you have a machine, a virtual machine and you need to have a second virtual machine,
which is pretty much exact same one as the other one.
Then, instead of spinning up a new virtual machine and installing the operating system from scratch
and doing the configuration, you could actually make a copy out of the another virtual machine.
And that copy actually means or actually referred or termed as clone or cloning.
All right, so this is all about the virtualization that I wanted to cover.
There's still many more things that you should know about virtualization, but I hope what I have covered
kind of have given you enough information in terms of the how the virtualization technology works.
If you still have many questions that that's perfectly fine.
You are more than welcome to send me a message, and I will definitely try my best to answer as as much
questions as you ask.
Thank you.