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You're going to need a lot of hardware to build out a private cloud.[/caption] One question that often comes up when speaking with IT pros: “What are the necessary components (i.e. hardware, software, virtualization, etc.) needed to build a relevant lab environment to test out and evaluate a private cloud architecture for my company?” When speaking at events, I often reference and demo a comprehensive private cloud environment I built along with a team of peers. This environment has all of the necessary hardware, software and virtualization assets to test and evaluate the merits of a private cloud architecture. As a point of reference, it consists of five current generation rack-mounted servers, which we were able to purchase new for this lab; each features quad processors and six cores (24 processors each) and 24 GB of RAM. This lab has a number of Hyper-V hosts as well as external iSCSI storage to allow all of the host machines to use a central repository for VM storage. From a hardware perspective, the “right” size for a lab depends on what you’re planning on evaluating, which determines the appropriate number of simultaneous VMs and host machines for a functional test bed. If you have the budget and/or you’re interested in truly evaluating performance of the private cloud components, going with new hardware for your lab environment is clearly the only option. In speaking to many customers, I’ve found it’s also not uncommon to use older server hardware (outside of the typical three-year hardware refresh cycle) as the host machines running Hyper-V or VMware ESXi. While many larger customers have a regular cycle of hardware coming out of production, it’s a bit more challenging to find parts for these servers when issues arise, due to the age of the hardware. Budget will ultimately dictate the hardware you’re able to procure, but the hardware in the private cloud lab should have the capacity to run all of the software components simultaneously—the better to understand the benefit and full effect of the private cloud. On the software side, there are a number of questions that need answering in order to help prepare for the build-out. For example:

- How many components of System Center am I planning on evaluating simultaneously?
- How many VMware software components will I need to keep running to mirror my current production environment?