The majority of private cloud conversations revolve around infrastructure as a service (IaaS). IaaS is a more natural progression from the consolidation and virtualization efforts going on in most data centers today. By adding automation, orchestration and provisioning portals, IT can gain efficiency and possibly lower costs over the virtualized data center. That being said, IaaS is not necessarily the right end goal because it still relies on the siloed application, operating system, server (virtual or physical) model.
A great end goal for the cloud model is PaaS. PaaS, or platform as a service, breaks the 1-to-1 relationship between OS and application/service, and provides for more fluid scalability. Additionally, PaaS platforms can remove the requirement for custom OS and server builds on a per-service basis, further reducing administrative
Within a private PaaS environment, applications and services are ported over to the PaaS platform and new applications are written directly for the system. Scalability, flexibility and availability are provided at some level by the PaaS layer itself, with additional options available at the infrastructure layer.
Additionally, because PaaS can be built over any infrastructure, a private PaaS has simplified portability to IaaS offerings in the public cloud. This in-house end-goal model and simplified portability make private PaaS an excellent option as either a migration tool or a permanent private model with public disaster-recovery (DR) possibilities.
An interesting example of private PaaS is Apprenda. Apprenda focuses on .Net and SQL Microsoft environments for its solution. In very basic terms, you provide its software with Microsoft Server and SQL Server instances, and it builds a fluid cloud development platform from them. Existing applications can be migrated into the PaaS cloud while new applications are being written directly to the platform. The entire system is agnostic to the infrastructure beneath; it only cares about the OS instances presented.
Private PaaS offerings such as this are fantastic for the enterprise, as they offer a simplified method of moving to end-goal service deployment thinking. They reduce or remove the need to focus on the underlying infrastructure. Instead of spending time on infrastructure concerns, IT is able to focus on capacity of processing and storage. Rather than focusing on specific builds for specific deployments, identical virtual or physical OS instances can be provisioned to the platform as needed.
The other advantage of this type of infrastructure is that when the platform is done right, the underlying server hardware is irrelevant. Physical and virtual servers of all shapes and sizes can be utilized because the platform cares only about the OS. This can allow for significant utilization of legacy equipment not ready for refresh and provide additional hardware choice flexibility.
When deploying private clouds, it's important to look as far out as possible to see where you think your IT service delivery will be. If PaaS or public cloud may be that end goal, private PaaS solutions should be considered for a first step. Rather than rebuilding your infrastructure and organization twice, you can start with PaaS functionality alongside consolidation and virtualization, or an existing IaaS platform.
Disclaimer: The vendors and products listed in this article do not comprise an all-inclusive list and are used for example purposes only. This article is not intended as an endorsement of any of the products mentioned.