Twenty computers, one box
A college wants a training room with twenty student computers, each with its own system, and a way for them to talk to each other. It has no money for twenty PCs and no space for them.
It buys one strong computer and makes twenty pretend computers inside it. Each pretend computer works like a real one.
Key words
| Word | What it means | Example |
|---|---|---|
| Virtual machine | a software computer that runs inside a real one | a virtual PC |
| Hypervisor | software that makes and runs virtual machines | |
| Host | the real computer that runs the virtual machines | |
| Guest | a virtual machine running on a host | |
| Type 1 hypervisor | a hypervisor that runs straight on the hardware | |
| Type 2 hypervisor | a hypervisor that runs as a program on an operating system | |
| Operating system | the main program that runs a computer | |
| Network | devices joined so they can share things | |
| Router | a device that joins networks and passes data on | |
| Virtualisation | making a software copy of something real | |
| CPU | the main processor of a computer |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can name the parts of a virtual environment and tell a type 1 from a type 2 hypervisor.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
A virtual machine is a software computer
A virtual machine (VM) acts like a real computer. It has a virtual CPU, memory, disk and network card. These are slices of the real computer, called the host. The VM itself is the guest.
You install an operating system in a VM just as on a real PC. The VM is saved as files on the host.
Kinds of virtual machine
| Kind | What it stands for | Example use |
|---|---|---|
| Virtual PC (client) | A desktop or laptop | A student workstation in a training room |
| Virtual server | A computer that gives a service | A web server or file server in a data centre |
| Virtual switch | A switch made of software | Joins the virtual PCs in one virtual network |
| Virtual router | A router made of software | Joins the virtual network to other networks |
The cells students fill in are left blank in this preview.
Extra: How many virtual cores does this machine see?
nprocA command for the lesson’s lab terminal. It is shown here and not run.
Extra: How much memory does it see?
free -m | head -2A command for the lesson’s lab terminal. It is shown here and not run.
Check
Have a go
Check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.