As is the case with many revolutionary ideas, Amazon stumbled upon the concept of offering IT infrastructure services to businesses in the form of a service. Realizing that it had built such a large, highly efficient data center that it could afford to capitalize on the excess capacity, the online retail titan decided to offer space on a pay-as-you-go basis. And while it would be inaccurate to say cloud computing was born, AWS put a public face on it, and Microsoft Azure, Rackspace Hosting and Softspace, soon followed suit.
Unlike a public cloud solution which is offered on a multi-tenancy model, meaning a company is assigned a slice of a server shared by other tenants or clients, a private cloud service is offered in a single tenant environment. Each client has its own dedicated hardware, network, and storage. Since a private cloud offers an exclusive environment, it is billed monthly rather than on a pay-as-you- go basis.
Private Cloud or Public Cloud?
Whether a company chooses to use a public or a private cloud depends on the purposes they have in mind. Those deploying a public cloud solution often use it to develop games or other programs where security is not an issue, or as a web server. Larger organizations with strict security or compliance requirements prefer private cloud services.
The Basic Facts
Both models are designed to appeal to different sectors.
Companies Using a Public Cloud
- Pay only for what they use, so if they choose to shut down after two hours, that is all they are billed for. There is no contract requiring that they make use of the server on an ongoing basis.
- Generally have a technical staff to manage the setup and details of the server, since being multi-tenancy and low cost, managed service is not included.
- Do not choose a network device, storage performance, or cache, but are assigned to a server that the cloud service provider designates for their use.
Companies Using a Private Cloud
- Some find that having dedicated hardware, network, and storage that other clients cannot access delivers the level of security their operations require.
- Are often bound by HIPAA,PCI DSS, or Sarbanes-Oxley compliance mandates and need a single client solution.
- Require the ability to customize the performance of the hardware, network, and storage they will be using.