Understanding Cloud Basics - Infrastructure As a Service

I have been getting multiple request to explain cloud in a very basic way and in steps.
So Starting off with this post we will try to understand very basics of the cloud computing - Infrastructure as a service.
Infrastructure as a service simply put is provisioning and using infrastructure on the fly and pay per usage of the infrastructure. The infrastructure includes the following things -
1) Servers, 2) Operating system, 3) VLANs, 4) LAN, 5) WAN, 6) Firewall and may be more.
A traditional IT infrastructure consists of the following things -
1) Physical Servers, 2) Network Switches, 3) Firewalls.
A typical provisioning of the infrastructure involves the following activities -
1) Order Physical servers, switches and firewalls
2) Rack up Physical servers.
3) Setup server network
4) Setup intranet connectivity
5) Setup firewall network
6) Setup internet connectivity
7) Install operating systems on each server
Unless you have an automation software, most of the above activities are manual and take a good amount of time to get it done. Let's look at typical time lines for the same -
Sr No Activity Time to accomplish Comments
1 Hardware ordering 3-4weeks Typical delivery time
2 Rack and power 1 day
3 Set up server 1 day
4 Set up intranet 1-2 day
5 Set up firewal 1-3 days
6 Set up internet 1-2 days

The highest amount of time is in hardware to arrive.

When you switch to cloud the activity time reduces to follow assuming the service provider is already selected -
Sr No Activity Time to Accomplish
1 Sign up the account 30min-1Hr
2 OS Image creation 2-3Hrs
3 Setup security 2-3Hrs

So maximum within a day your setup is ready and when you want to scale this time further goes down to not more then 30 min as the base setup is ready and re-usable.

So how does the magic happen?
There is no magic. Its a combination of things below -
1) Service Provider
2) Provisioned hardware capacity
3) Virtualized infrastructure
4) Clouded APIs :)

What happens in the background is as follows -
Service provider builds cloud services as follows -


And there you have it. Check out the following clouds -
http://aws.amazon.com/products/




There are many more Infrastructure as a service provider but above gives you an idea of using cloud for infrastructure as a service.

Feel free to comment on the post if you had like to see more details on this topic.