A Modern Pantheon

A modern data center still shares many aspects with ancient architecture, structurally and in service. The form literally follows the function. The purpose of both the Pantheon and a data center is to provide services. To provide services, its requirements for continual functioning must be met. This is the design team's primary concern. The design of the data center must revolve around the care and feeding of the service providing equipment.

These functional requirements of the data center are:

A place to locate computer, storage, and networking devices safely and securely
To provide the power needed to maintain these devices
To provide a temperature-controlled environment within the parameters needed to run these devices
To provide connectivity to other devices both inside and outside the data center

In the design philosophy of this book, these needs must be met and in the most efficient way possible. The efficiency of the data center system relies entirely on the efficiency of the design. The fundamental principles of a data center philosophy should be your guiding principles.

The phrase "design philosophy" could have many different meanings. For the purposes of this book we'll use the following definition: A design philosophy is the application of structure to the functional requirements of an object based on a reasoned set of values.

Fundamentals of the Philosophy

There are five core values that are the foundation of a data center design philosophy: simplicity, flexibility, scalability, modularity, and sanity . The last one might give you pause, but if you've had previous experience in designing data centers, it makes perfect sense.

Design decisions should always be made with consideration to these values.

Keep the Design as Simple as Possible

A simple data center design is easier to understand and manage. A basic design makes it simple to do the best work and more difficult to do sloppy work. For example, if you label everything ”network ports, power outlets, cables, circuit breakers, their location on the floor ”there is no guess work involved. When people set up a machine, they gain the advantage of knowing ahead of time where the machine goes and where everything on that machine should be plugged in. It is also simpler to verify that the work was done correctly. Since the locations of all of the connections to the machine are pre-labeled and documented, it is simple to record the information for later use, should the machine develop a problem.

Figure 1-1. Simple, Clean, Modular Data Center Equipment Room

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Design for Flexibility

Nobody knows where technology will be in five years , but it is a good guess that there will be some major changes. Making sure that the design is flexible and easily upgradable is critical to a successful long- term design.

Part of flexibility is making the design cost-effective. Every design decision has an impact on the budget. Designing a cost effective data center is greatly dependent on the mission of the center. One company might be planning a data center for mission critical applications, another for testing large-scale configurations that will go into a mission critical data center. For the first company, full backup generators to drive the entire electrical load of the data center might be a cost-effective solution. For the second company, a UPS with a 20-minute battery life might be sufficient. Why the difference? If the data center in the first case goes down, it could cost the company two million dollars a minute. Spending five million on full backup generators would be worth the expense to offset the cost of downtime. In the second case, the cost of down time might be $10,000 an hour . It would take 500 hours of unplanned downtime to recoup the initial cost of five million dollars of backup generators.

Design for Scalability

The design should work equally well for a 2,000, 20,000, or 2,000,000 square foot data center. Where a variety of equipment is concerned , the use of watts per square foot to design a data center does not scale because the needs of individual machines are not taken into consideration. This book describes the use of rack location units (RLUs) to design for equipment needs. This system is scalable and can be reverse-engineered.

Use a Modular Design

Data centers are highly complex things, and complex things can quickly become unmanageable. Modular design allows you to create highly complex systems from smaller, more manageable building blocks.

These smaller units are more easily defined and can be more easily replicated. They can also be defined by even smaller units, and you can take this to whatever level of granularity necessary to manage the design process. The use of this type of hierarchy has been present in design since antiquity.

Keep Your Sanity

Designing and building a data center can be very stressful. There are many things that can, and will, go wrong. Keep your sense of humor. Find ways to enjoy what you're doing. Using the other four values to evaluate design decisions should make the process easier as they give form, order, and ways to measure the value and sense of the design decisions you're making. Primarily, they help to eliminate as many unknowns as possible, and eliminating the unknowns will make the process much less stressful.