Date:   Wednesday , February 05, 2014

In defining Infrastructure as a Service we need to drill into specific characteristics that a cloud platform provider must provide to be considered Infrastructure as a Service. This has been no easy task as nearly every cloud platform provider has recently promoted features and services designed to address the infrastructure as a service and cloud computing market. Fortunately, as the technology has evolved over time, a definition of cloud computing has emerged.

As a metaphor for the Internet, \"the cloud\" is a familiar cliché, but when combined with \"computing,\" the meaning gets bigger and fuzzier. Some analysts and vendors define cloud computing narrowly as an updated version of utility computing: basically virtual servers available over the Internet. Others go very broad, arguing anything you consume outside the firewall is \"in the cloud,\" including conventional outsourcing.
Cloud computing comes into focus only when you think about what IT always needs: a way to increase capacity or add capabilities on the fly without investing in new infrastructure, training new personnel, or licensing new software. Cloud computing encompasses any subscription-based or pay-per-use service that, in real time over the Internet, extends IT\'s existing capabilities.

Migration to the Cloud

The hype surrounding cloud services may make it seem like all of an organization\'s resources should be migrated to the cloud immediately. There is no denying that, in certain cases, cloud services can be tremendously beneficial. In others, however, a cloud migration probably does not make sense.
Organizations need to take a hard look at their existing investments in infrastructure -- from hardware to application portfolios to network architecture and beyond -- to determine if a move will be beneficial. Some of the migration questions are technical, such as whether a given application can perform adequately in the cloud; some questions will involve nontechnical, budgetary issues, such as whether a cloud migration is cost-effective given current investments in infrastructure.

One of the first considerations is an organization\'s existing data center investment. Despite technologies such as server virtualization, there are real costs associated with deploying on-premises servers. There are not only licensing costs involved, but also costs associated with hardware resource consumption and support infrastructure. As such, there is almost always a significant investment associated with an on-premises server. Outsourcing a server\'s data and/or functionality to the cloud may mean abandoning your on-premises investment unless an on-premises server can be repurposed.

Although this rip-and-replace approach to cloud migrations may not make financial sense for organizations that have a large investment in an on-premises data center, an organization can still benefit from migrating certain on-premises resources to the cloud.

No matter how good it is, any server hardware eventually becomes obsolete. Enterprise-class organizations have traditionally coped with this expected obsolescence by adopting a hardware lifecycle policy. An organization, for example, might choose to retire servers after five years. That being said, an organization could integrate a cloud services roadmap into its hardware lifecycle policy. Doing so allows IT teams to migrate on-premises resources to the cloud instead of moving them to newer hardware.

The prospect of using cloud services is often particularly attractive for smaller organizations and startups. In the case of a smaller organization, the use of cloud services provides access to enterprise-class hardware and fault-tolerant features that would otherwise be unaffordable. Similarly, startups can benefit from cloud services because they can get their operations running quickly without having to invest in on-premises data center resources.

The Hybrid Cloud Approach

The hybrid approach allows a business to take advantage of the scalability and cost-effectiveness that a public cloud computing environment offers without exposing mission-critical applications and data to third-party vulnerabilities. This type of hybrid cloud is also referred to as hybrid IT.

To be effective, a management strategy for hybrid cloud deployment should address configuration management, change control, security, fault management and budgeting. Because a hybrid cloud combines public cloud and private data center principles, it is possible to plan a hybrid cloud deployment from either of these starting points. Picking the better starting point, however, will make it easier to address business goals.
A primary goal of a hybrid cloud deployment should always be to minimize change. No matter how similarly a public and private cloud are matched, design differences will inevitably exist. The greater the differences between the cloud environments, the more difficult it will be to manage multiple clouds as a single entity.