Virtual machines vs Containers

Question 1

Define virtualisation

Answer 1

The process of presenting a system resource as multiple resources.

Question 2

What do VM’s and Containers virtualise?

Answer 2

VMs virtualise entire system stacks down to the hardware level.

Containers virtualise software from the OS and above.

Question 3

What is a container?

Answer 3

Containers are lightweight software packages holding software at the OS level and above.

Multiple containers can be hosted on the same physical machine.

Question 4

What are the pros and cons of using Containers?

Answer 4

Pros:
- Speed
- Lightweight
- Pre-made containers for rapid set-up
- Microservice compatibility

Cons:
- Shared hosting system. If issue effects hardware all client containers are effected.

Question 5

What is a VM?

Answer 5

A VM is an entire computation system shipped as software that a client can use.

Virtualisation of an entire system.

VMs are barebones systems and can be reconfigured at low levels as per the client need.

Question 6

What are pros and cons of VMs?

Answer 6

Pros:
- Each VM is independent from one another at the OS level, as opposed to containers that share a host OS.
- Great customisation due to barebones system being delivered.

Cons:
- Being a full system stack reduces speed
- Large VMs take up memory on hosting machine.
- More complicated set-up