7.3.1 The key features of virtual environments

Question 1

Define:

Virtualisation

Answer 1

The technology that enables a single physical hardware system to be separated into multiple simulated environments or dedicated resources

Question 2

State:

“Software that connects to the hardware and facilitates the splitting of one system into separate and distinct environments referred to as VMs”

Virtual Environments

Answer 2

Hypervisor

Question 3

Fill The Blank:

VMs rely on the hypervisor to separate the …………………… of the machine from the hardware and distribute them and hardware that is equipped with a hypervisor is called the …………. and VMs are called ……………..

Answer 3

Resources, Host, Guest

Question 4

Fill The Blank:

The guests treat the resources such as the …….., memory and …………… as a ………….. of resources and receive only what they require from the ……………….

Answer 4

CPU, Storage, Pool, Operator

Question 5

State:

2 examples of types of virtualisation and briefly explain them

Answer 5

2 of:
* Data virtualisation - Treat data as a dynamic supply, provide processing functions that can bring data together from multiple sources and tranform data and accommodate new data sources
* Desktop virtualisation - Install multiple OSs onto a single machine, to allow a central admin to install simulated destop environments on very large quantities of physical machines simultaneously - allowing mass configuration, updates etc.
* Server vritualisation - Allow a server to serve multiple functions at once (involves partitioning)
* OS virtualisation - Load multiple types of operating system side by side, making multiple accessible on one device reducing hardware costs and increases security as all virtual instances can be monitored
* Network function virtualisation - Seperate key network functions independent of hardware, allowing them to be packaged together to form a new network, reducing number of physical components required to create multiple independent networks

Question 6

State:

5 key features of virtual environments

Answer 6

4 of:
* Increased security - Manager can control and filter activity of guest’s programs; mitigate risk of harmful operations being carried out
* Managed execution - Execution of sharing, aggregation, emulation and isolation managed from central virtual server
* Sharing - Creation of separate computing environments within same host reduces number of active servers and limits power consumption
* Aggregation - Group of hosts are combined and presented to guests as a single virtual host - done with cluster management software
* Emulation - Guest programs are executed in an environment that is controlled by a virtualisation layer, which allows for completely different environments to the host to be smulated meaning execution of guest programs that require specific characteristics
* Isolation - Each guest has a separate environment and the VM can filter activities of the guests and mitigate the risk of harmful operations against the host - also allows performance tuning
* Portability - hardware virtualisation = Virtual image of guest can safely be moved and programming-level virtualisation = binary code representing application components can run on any installation of the corresponding VM