In the last portion of this module, we
will look at the virtual desktop and
virtual application streaming. First of
all, what is the virtual desktop or most
commonly called virtual desktop
infrastructure, or VDI. Virtual desktop
infrastructure refers to the process of
running a user's desktop inside of virtual
machine that lives in a server in the
datacenter. It enables a fully
personalized desktop for each user with
all of the security and simplicity of
centralized management. A personal
computer if we look at it has the same
architecture as an industry standard
server. You have the hardware, the
operating system, and the applications.
Similar to how a server can be
virtualized, so can a personal computer.
The operating system and applications
running on it can become in sort a virtual
machine. In the same way, a number of
virtual servers can be hosted on a
physical server, so can a number of
virtual desktop PCs be hosted on a
physical server. Virtual desktops can,
like virtual machines, be moved from host
server to another providing benefits in
terms of load balancing and resilience to
your infrastructure. And while this move
takes in place, the virtual machine can
continue to operate. In a desktop
virtualization scenario, the client still
needs to have a computer with a monitor,
mouse, and network, but it doesn't need to
be powerful at all. Since there are barely
any resources used on the host computer,
its sole job is to connect to the virtual
desktop. For the hardware aspect, most
users will use what we call is a thin
client. A thin client is a stateless
file-less desktop terminal that has no
hard drive. All of the features typically
found on the desktop PCs including
applications, sensitive data, memory are
restored back in the datacenter when using
a thin client. Because of no moving parts
and the fact that it's really basic, it
has a high reliability and a low cost.
Because it doesn't need to be powerful and
only needs basic ports, it also has a
really long lifetime. We can look up to 10
years for a thin client. And even if
something goes wrong, it's super easy to
replace because you don't need to migrate
any applications or any of the user's data
when the hardware goes wrong. You simply
put another thin client, a thin desktop,
and the user will connect to the same
virtual desktop where everything is at.
And also, the maintenance and the
electricity costs are super low because of
the basic hardware. Desktop virtualization
can also be used from a laptop. So users
can work from anywhere in the world, as
long as they have a network connection and
a way to reach out to your VDI
infrastructure and this can also ease the
aspect of bringing your own device in the
enterprise. Lastly, of course, while less
common, VDI can also be consumed from a
desktop, but a desktop does not need to be
a fully blown machine. It can be an older
desktop, which is not powerful enough to
run today's application locally anymore.
So the benefits of a virtual desktop
infrastructure are the hardware cost
savings because we don't need to buy
powerful PCs for every user every few
years, a better load balancing and
resilience on the backend ensuring that
users have a great experience every day.
Deploying new computers is also faster
since everything is virtualized on the
backend. And finally, all of the desktops
are centrally managed and backed up by IT.
So the data is not stored on the user's
computer. Everything is stored centrally
in an environment controlled by IT so it
makes it easier to back up, manage, and
ensure that sensitive information is well
protected. There are multiple vendors out
there that provide products for virtual
desktop virtualization, but the biggest
ones, at least in my opinion, are Citrix
XenDesktop, Microsoft remote desktop
services, and VMware Horizon. Feel free to
check them out, and of course, do your own
research because those are not only
vendors available out there. There are
many others, those are just some three of
the biggest names out there. Now let's
talk a bit about our next subject, which
is application streaming. Application
streaming is a form of on-demand software
distribution. Instead of virtualizing the
whole desktop, you only virtualize the
application or some portions of it so a
part of it stays on the user's computer
while a part of it is centralized or
virtualized in the datacenter. So how
exactly does it differ from virtual
desktop infrastructure? So we have our
normal desktop where everything runs
locally from hardware to operating system
to applications. Then we have the desktop
virtualization that we have just covered a
bit before where the operating systems and
apps are all virtualized. And with
application virtualization or application
streaming, the client has the operating
system installed locally and just enough
bits of the app in order to run it, but
the application runs, in fact, on a
virtualized environment on a server. The
client computer still needs to run the
operating system, but a system doesn't
need to be too powerful because only a
part of the app is installed locally. All
of the heavy lifting is done on the
backend server that runs the virtualized
application. And this doesn't only apply
to desktops. It can apply to tablets and
smartphones as well. So what are the
benefits of application streaming? First
of all, a lot less conflicts between
applications and operating system because
the application runs in a controlled
environment on the server. It also
centralizes and simplifies application
patching and updating since everything is
controlled by IT and it can reach all of
the users instantly. It also accelerates
application deployment for the same
reason. An app only needs to be deployed
on the servers and then it's available
almost instantly to all of the users. Some
of the major vendors include Citrix
XenApp, Microsoft App-V, and VMware
ThinApp. But again, there are others out
there and it's always good to do your own
research of what each one offers and which
one is best either for you to learn or for
your current project which one would server your client or company better.