TEST ECRIT le 30 avril 2015 sur les lectures préparées (test 2)
(7 points sur 40 total année)
Le test comportera les mêmes types de prestations que celui du 2 avril.

Vous préparerez seuls ce dossier; vous aurez l’occasion de poser toutes vos questions le 23/4.

Vous avez reçu le 2 avril un texte d’introduction au sujet (Welcome to Oracle VM Virtual Box).
! attention au mot « consolidation » (= faux ami) à comprendre avec précision.

Avant de le lire, regardez ces trois vidéos :

1. Celle-ci (How to use VirtualPC, David McClelland) n’est pas toute récente mais elle a le mérite d’être très claire. Transcription disponible sur le site, mais commencez par essayer de comprendre sans la consulter. (Profitez-en pour découvrir VideoJug : des vidéos en vrac sur les sujets les plus divers, des plus sérieux aux plus légers – avec transcriptions ! )

2. Virtualization overview (VMWare) – (distinguer les informations réelles du blabla publicitaire)

3. A simple explanation of virtualization (vminformer)

mise à jour 12/4/15
– Lecture à préparer, suite et fin :
http://www.extremetech.com/computing/198427-how-to-install-windows-10-in-a-virtual-machine (pages 1 et 2)
S’il y a des notions inconnues pour vous (ex : image ISO…), à charge pour vous de chercher les informations nécessaires !
Vous recevrez à la rentrée la version papier de cet article pour le test (mais les saisies d’écran risquent de vous paraître très petites, aussi aurez-vous sans doute intérêt à les compléter à la main d’après la version en ligne).

…Et si vous essayiez de mettre en pratique ? cela vous permettrait de mieux comprendre l’article.

___________________________________

Transcripts :

1. VMWARE VIRTUALIZATION BASICS

Over the years, IT complexity has grown while efficiency has plummeted.
Virtualization reverses this trend,
simplifying IT infrastructure so you can do more with less.
Virtualization lets you run your applications on fewer physical servers.
To virtualization each app and operating system live in a separate software container
called a virtual machine or VM.

0:30 VMs are completely isolated,
but computing resources – CPUs, storage and networking – are pooled together
and delivered dynamically to each VM by software called a hypervisor.
Every application gets what it needs for peak performance.
With all your servers running at full capacity, you don’t need nearly as many.
Hardware count and overhead drop dramatically
while application performance improves by leaps and bounds.
Bottom line : greater value at lower cost,
with less complexity and faster maintenance.
Now you can spend more time on innovation to meet real business needs.

1:04 But all virtualization is not created equal.
For the smallest companies as well as the largest global enterprises,
VMWare is far and away the most trusted and widely deployed platform.
Out technology is the most mature, feature-rich and reliable,
generations ahead of any other.
With VMWare you get higher service levels,
two and three times higher for heavy workloads,
and IT management gets a lot simpler.

1:32 Tasks that used to take all night can be done over coffee in the afternoon,
freeing up work time for innovation
and evening hours for spending with your family.
No business can afford application downtime
and VMWare Virtualization makes sure it won’t happen to you.
High availability and fault tolerance are built right into the platform.
If a server ever fails, your apps stay up and running,
with no downtime, no data loss and no need for human intervention.

1:58 VMWare Virtualization brings you the biggest savings
by letting you run more apps on many fewer servers
at the industry’s lowest net virtualization cost.
Even better, the savings in efficiency multiply with every application you virtualize.
Of course protecting IT against intrusions is critical.
That’s why VMWare shields virtualized apps and data
with unified, easy-to-use security across all levels.
In fact, VMWare protection makes your virtual assets even more secure
than the most fortified physical environments.

2:30 Virtualization is a must for today’s IT environment.
At the same time advancing and protecting your business
means choosing your virtualization solution wisely.
Go with a trusted platform that delivers the greatest benefits,
the largest savings and the highest responsiveness to your business : VMWare.

2. A SIMPLE EXPLANATION OF VIRTUALIZATION

Hello, and welcome to vminformer’s videoguides on virtual computing.
The first question to answer is : Why virtualization ?
Well, its simple : it saves money and resources.
Of course you’d like us to tell you how it works,
so here is a simple introduction.
Virtualization, or virtual computing,
makes one physical computer act and perform like many computers.

0:26 Every computer, irrespective of its power, size or age,
from the smallest PC to the biggest mainframe,
has four attributes.
Each one has a processor – the chip that does the work;
some memory – the chips that remember the task and how to do it;
some storage – which files everything away,
and a network connection.
Because we rely on computers for every aspect of our business life,
there are hundreds of servers, PCs and laptops in most organizations,
but they all have the same name need for these four things.

1:01 So virtualization works as follows.
A big piece of hardware with plenty of power
and processing, memory, storage and network capacity
is loaded with a piece of software called a hypervisor.
The hypervisor is sometimes called the abstraction layer
because it abstracts the physical resources
and reallocates them more efficiently.

1:25 In this diagram, above the abstraction layer is a guest computer,
or as some people call it, a virtual machine.
These virtual machines are just very big files.
The guest computers run inside the physical hardware,
which is called the host.
An example of how virtual machines run inside a computer
is the sending and receiving of some data through the network.
Sent data leaves the guest computer,
it travels through the hypervisor to the network card on the host
and forward (?) to its eventual destination.
The same works in reverse when receiving data.

2:04 Why would you do this ?
Well simply because you can run many machines simultaneously
over one physical hardware
so it can save money on hardware,
consolidate management,
reduce energy use,
and it becomes a much more efficient use of resources.
Most computers operate using between only 4 to 7 percent of their resources.
By virtualizing these computers,
you can get many guests onto one host.

2:32 Immediately you’re gonna get much greater efficiencies in power consumption,
physical space and energy used for cooling.
Of course you should need less people to look after that equipment.
Now when you need a new server, you don’t need to buy new hardware,
you can make a virtual one.
If you need more memory or CPU on a device,
your administrator just changes the resource allocation with a few mass clicks.

2:59 So what can you virtualize ?
Well, anything that has the four attributes of a computer.
Even a network and switching between computers
can be consolidated onto the same platform.
There are more benefits.
When you have two host servers,
then you have the ability to move machines around
so valuable resources are optimized at all times.
It’s quite possible to move a powered on guest computer from one host to another.
You might do this because the first host is overloaded
or because there has been a catastrophic hardware failure of the original host.
Maybe you get cheaper processing power somewhere else,
which introduces the concept of cloud computing.

3:41 However, this flexibility does raise some questions :
where are your machines ? who has access to these systems ?
how are they managed ? what security is in place ?
Our other videos on virtualization with management
outline what is involved in these and other risks
and what you can do to address them.
Understand and address these issues,
and you should be able to continue your virtualization journey with confidence.
4:08 (…)