Scope, Budget, and Criteria

An important distinction to make at this point is what really constitutes the elements of a data center. When we talk about the data center, we are talking about the site, the Command Center (if one is to be added), the raised floor (if one is to be added), the network infrastructure (switches, routers, terminal servers, and support equipment providing the core logical infrastructure), the environmental controls, and power. Though a data center contains servers and storage system components (usually contained in racks), these devices are contents of the data center, not part of the data center. They are transient contents just as DVDs might be considered the transient contents of a DVD player. The data center is more of a permanent fixture, while the servers and storage systems are movable, adaptable, interchangeable elements. However, just as the DVD is of no value without the player and the player is of no value without the DVD, a data center without equipment is an expensive empty room, and servers with no connection are just expensive paper weights. The design of the data center must include all of the elements. The essential elements are called the criteria.

Project Scope

Most often, it is the project scope that determines the data center design. The scope must be determined based on the company's data center needs (the desired or required capacities of the system and network infrastructure), as well as the amount of money available. The scope of the project could be anything from constructing a separate building in another state with offices and all the necessary utilities, to simply a few server and storage devices added to an existing data center. In either case, those creating the project specifications should be working closely with those responsible for the budget.

Budget

Designing a data center isn't just about what the company needs or wants, it's what they're willing to pay for.

Using project scope as a starting point, the criteria for the data center can be loosely determined, and a comparison between how much this will cost and the budget will determine the viability of the project. Is there too much money or too little? (Okay, in theory you could get more money for the data center than you need, but this rarely happens.) Then the balancing act begins. If there isn't enough money in the budget to cover the cost of essential elements, either more money must be allocated, or some creative modifications must be made to the project scope.

The process for determining a budget, deciding what parts of the data center will receive what portion of it, and putting together a center based on designated funds is one of negotiation, trade-offs, compromises, and creativity. Also, there is probably more than one budget for the data center, and how the money is allocated depends on numerous factors specific to the company.

Planning a data center is part of larger business considerations, and both designers and those setting the budget must be flexible. Accountants telling the data center designers, "Here's how much you get. Make a data center," probably won't work. By the same token, designers demanding enough money for the ideal data center probably won't meet with approval by the accountants . When negotiating for funds, the best idea is to have several alternative plans.

Some questions and considerations that must be examined in the beginning might include:

• What is the budget for the data center?

• Are the project scope and the budget a realistic balance?

• Is there enough money to create an adequate center for the company's needs?

• How much do you actually need to create the center?

• How will funds be distributed? Can funds be redistributed?

• Factor in running costs, servicing , and maintenance contracts with maintenance suppliers.

• Factor in redundancy of power/services/HVAC/UPS.

• Consider carefully all possible future modifications, upgrades, changes in power needs, and system additions in the design.

The toughest thing about designing a data center is working within the budget. The budget will force you to make compromises and you must figure out whether or not you are making the right compromises. You might be able to cut costs by removing the backup generators from the budget, but you must weigh the risk of such a decision. There is the possibility that the data center power might fail and systems would be out of action without backup power. Every compromise carries a degree of risk. Do the risks outweigh the cost? Figuring out how to meet the budget is where your finance people and risk analysts really come into play. Use their expertise. Here are a few questions you might work out with your finance and risk team.

• If cost exceeds budget, can anything be removed or replaced with a less expensive alternative?

• Are all redundant systems really necessary?

• How much will projected failures (downtime) cost compared to initial costs for redundant systems?

• Is a separate Command Center necessary?

• Can amortization schedules be stretched from, for example, three years to five years so there is money available for other needs?

• Can certain areas be expanded or upgraded later?

• What is the best time to bring the facility online? In the U.S., amortization doesn't begin until you occupy the space. Would it be better to take the amortization hit this fiscal year or the next ?

A final point to consider: As with many aspects of data center design, the money spent on planning is invariably money well spent. It costs money to build a data center, and part of that expenditure comes right up front in coming up with a budget. Money spent on creating an accurate budget can actually save money in the long run.

Build Budget and Run Budget

The build budget is the money allocated to build and bring up the data center. The previous three sections describe what is covered by the build budget (or budgets , if separate). But you must also consider the run budget which is the amount of money allocated for yearly operating costs, maintenance, repair, ISP network connectivity, service and support agreements on computers, storage and network equipment, and the cost of electricity. These should be considered as part of the run budget.

Criteria

The most important criteria for a data center can be put into the following categories:

• Location (or site)

• Essential criteria

• Secondary criteria

Location

It would seem that the site you choose for your data center would be considered one of the essential criteria. It's true that where you choose to locate the data center site (region/building) is important, but this choice is based on many different factors. For example, a company wants to build a new data center near their corporate offices in Cleveland, Ohio. To meet project scope on the essential criteria, it is determined that several million dollars more are needed, just to secure the site location. Suddenly, building in Cleveland doesn't seem as critical if a few million dollars can be saved by locating the building one hundred and sixty miles away in Milford Center where land prices are much cheaper.

Also, connectivity through the company's network infrastructure has made it possible for a data center to be located wherever it is practical and affordable. A data center can even use multiple locations, if necessary, connecting through the network. In this way, location is a very flexible and negotiable criteria.

Essential Criteria

There is a hierarchy of essential criteria. All data centers must have the following four elements in whatever capacities are needed or available. Though they are listed in order of importance, a data center cannot run without all of them working interdependently. It is only their values that are negotiable.

• Physical capacity. You must have space and weight capacity for equipment, and therefore, the other three criteria. There must be space for the equipment and the floor must be able to support the weight. This is a constant.

• Power. Without power nothing can run. Power is either on or off. Connections to different parts of the grid and/or utilizing a UPS increases uptime. You must have physical capacity to have room for power and the equipment that needs power.

• Cooling. Without cooling nothing will run for long. This is either on or off, though redundancy increases uptime. You must have physical capacity and power to run HVACs.

• Bandwidth. Without connectivity, the data center is of little value. The type and amount of bandwidth is device dependent. You must have physical capacity, power, and cooling to even consider connectivity.

Unless the data center will be used for non-mission-critical operations, the last three criteria should be designed to be up and running 100 percent of the time.

The use of these elements is non-negotiable, but their values are negotiable. Consider a decision about power redundancy. A UPS system (batteries that kick in when the power goes out) is less expensive than creating a power generation plant, but it has a limited run time. For a mission-critical operation, the 20 minutes of power a UPS might give you could be insufficient.

Let's say the UPS costs $1 million, and the power generation plant costs $3.5 million. The track record of the power company shows that they're down an average of 15-minutes once a year. For your company, a 15-minute power outage equals two hours for the outage and recovery time. Two hours of downtime costs the company $500,000. With a UPS system, there would be no outage because the 20 minutes afforded by the batteries would easily cover for the 15 minute outage and there would be no recovery time needed. Therefore, it would take two years to recover the $1 million dollar cost of the UPS, whereas it would take seven years to recover the cost of the power generation plant. If the power company has a greater problem with power outages, the generators make sense. Or relocating to an area with more dependable power might make more sense.

Secondary Criteria

The essential criteria must be included in the design in whatever values are available. However, there are invariably other criteria that must be considered, but they are secondary. The level of importance of secondary criteria is wholly dependent on the company and project scope. It's conceivable that the budget could be trimmed , for example, in fixtures, but it's likely that you'll want to budget in overhead lighting so data center personnel won't have to work with flashlights held between their teeth. Still, you can see that some criteria is very flexible.

Examples of secondary criteria are:

• Fixtures such as plumbing and lighting

• Walls, doors, windows , offices, loading dock

• All of the miscellaneous hardware, security cameras , card readers, door knobs , equipment cabinets , etc.

• Equipment such as forklifts and pallet jacks

• A Command Center

These will vary depending on whether you're building a new structure or retrofitting an old one, but what is key is the negotiating value of these elements.

The equation for the total budget is:

or

Using Rack Location Units

A concept that will help the data center designer considerably in determining the essential criteria (how much equipment can the center support and what capacities are necessary to support the equipment) is that of rack location units (RLUs). These are numbers based on the operating requirements of each rack in the data center. A rack could be considered to have specific RLU values based on its essential requirements (power, cooling, etc.) and these numbers could be used in relation to other devices with the same, or similar, requirements. In a data center with varied equipment, more than one RLU definition is usually required. For example, all of the storage racks in one section of the data center might be considered to be all RLU-A racks, and all the server racks might be considered RLU-B racks.

This is a very important design concept to understand and is covered in greater detail in Chapter 4, "Determining Data Center Capacities."