One building, five offices
A company rents one big building. Inside, it builds five separate offices with walls, doors and their own phones. Nobody in one office can walk into another.
It is still one building. But it acts like five.
Computers can do the same trick.
Key words
| Word | What it means |
|---|---|
| Virtualisation | making a software version of something that is really hardware |
| Virtual resource | a software version of a real part, such as a virtual disk or virtual network |
| Physical resource | a real part you can touch, such as a disk or a switch |
| Partitioning | cutting one physical resource into several parts |
| Isolation | keeping each virtual resource apart from the others |
| Encapsulation | packing something into one self-contained bundle, such as a file |
| Hardware independence | running the same way on different kinds of hardware |
| Network | computers and devices joined together so they can share data |
| Virtual machine | a computer made of software that runs inside a real one |
| Hypervisor | software that makes and runs virtual machines |
| Router | a device that passes data between networks |
| Operating system | the main software that runs a computer |
| Database | an organised store of data that can be searched |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can explain five ideas of virtualisation and name five places it is used.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Many from one, and one from many
Many from one. One physical resource is split into many virtual ones. This is partitioning. One server becomes ten virtual servers. One disk becomes three drives.
One from many. Several physical resources are joined into one virtual one. Three disks become a single big drive. Four servers act as one pool.
You met the same idea as sharing and aggregation in the core lessons.
Isolation, encapsulation, hardware independence
Isolation. A fault or a virus in one virtual resource does not reach the others.
Encapsulation. A virtual resource is packed into a bundle, often a set of files. You can copy it, back it up or move it like any file.
Hardware independence. The bundle does not care which brand of host runs it. Move it to a new host and it still works.
Check the ideas
Have a go
Check the ideas
4 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.