Sunday, November 6, 2011
Why public cloud
Because of the risks, especially those relating to security and loss of control over where data resides, your organization may prefer the private cloud option, which, as I have said previously, is still a good option that provides you with the benefits of reduced number of physical machines along with lower electricity and cooling needs, as well as needing fewer staff to administer the machines.
However, unless your organization has hundreds of thousands of employees, a private cloud is not going to give you the cost savings that come from the economies of scale that public clouds enjoy.
To implement the private cloud, you’ll need upfront investment to virtualize your servers and add the software needed to operate it as a cloud. You are not going to just pay for what computing resources you need - - you basically still have to maintain the systems you need for your worst-case computing load.
Some go as far as to say that a private cloud is not a cloud at all because a cloud should have “elasticity” - - meaning you can create new virtual machines on demand and shut them down when you don’t need them. A private cloud cannot easily provide this elasticity, unless it’s for a huge number of employees.
With a public cloud, you can truly pay for computing as you go - - just buy what you need, when you need it. That’s why, unless you have hundreds of thousands of employees or information that’s very sensitive (like military information), you have to consider public clouds to get the benefits of cloud computing. If that’s not acceptable, you can consider a community cloud suitable for your organization. For example, government agencies could opt for a government community cloud where you could at least get some economies of scale.
Here's some more information to help you
Please see my previous blog posts on what is cloud computing, why you should consider it, and some risks of cloud computing.
Here are some books on cloud computing that you may consider: