By alkagupta on Nov 06, 2009
So, there you have it. Every CIO there is being tasked these days to potentially reduce costs and accelerate the time to market by incorporating this Mantra in their data center. Either by building in-house or by buying the service from an external vendor that offers these features to the user.
Its no news that Virtualization and Cloud Computing go together. Virtualization enables Cloud Computing, and in fact is one of the key under lying technology enabling the Cloud. However, often people are left wondering if Cloud Computing is no more than "Next-Gen Virtualization". In my mind, Yes and No, especially if you are talking about Private Clouds. I got motivated to write this piece to bring some clarity to this topic.
A Cloud is virtualized by definition, but the degree of cloudiness depends on the level of automation and self service that is built into it. If the offering is a Public Cloud, then it must incorporate almost all principles of a Cloud Computing architecture that include multi-tenancy and pay-as-you-go model, enabled by a virtualized self-service platform with built-in services like billing, metering, charge back, along with public APIs or a Portal for public access to the Cloud. This is much more than an evolved virtualized environment, where you can quickly get a pre-deployed server or a service, ready to use, but does not necessarily have all these other built in services like self-service and pay-as-you go. In fact, a cloud service should be such that it can be abstracted for use on an as-need basis, and not just be a service that can be used over the internet.
In case of a Private Cloud, the users are more targeted and there is more leeway in how much of Cloud Computing principles are built into the infrastructure. Infact, most enterprises are going with the incremental approach so as to leverage their existing legacy systems, yet begin to harvest the benefits of Cloud Computing. This is making Hybrid Clouds more popular where enterprises can spin off certain type of functional workloads or burst loads to an external Public Cloud. Several Public Cloud vendors are offering this feature where the customers can embed the compute nodes from the public cloud into the company VPN, hence making the public cloud nodes part of the company data center. While this architecture has some security concerns, given the public compute nodes in most cases are physically not separate from other nodes in the cloud, it being a virtualized environment, its still a good mid-way between an exclusive public cloud and a private cloud. Its worthwhile to mention here that there are companies like GoGrid and Rackspace who would offer dedicated hardware in their data centers to complement an enterprise private data center. However, the more dedicated the hardware, less are the cost and flexibility benefits of a cloud available to you.