Choosing an Optimal Location for Your Data Center

This chapter explains how to choose an appropriate location for your Data Center, from the hazards you should avoid to the physical attributes you want. The chapter spells out the risks that can jeopardize a Data Center site, how to safeguard your server environment against them, and what agency to go to in order to learn if a specific parcel of land is susceptible. Finally, the chapter outlines what seemingly minor building elements can make or break a property's suitability to house a Data Center.

Assessing Viable Locations for Your Data Center

When the time comes for your business to build a server environment, it is essential that the people responsible for the Data Center's design have an opportunity to provide input into where it is constructed. Traditionally, upper management decides what property to purchase, based upon a variety of a company's wants, needs, and business drivers. Other purchase considerations might include a parcel's price tag, its proximity to a talented labor pool, advantageous tax rates, or the desire to have a corporate presence in a particular geographic area. Whatever the drivers are, a property's suitability to house a Data Center must be among them. Purchasing or leasing a site without considering this greatly hampers the Data Center's capability to protect company servers and networking devices. Not making this a consideration also invariably leads to additional expense, either to retrofit the land's undesirable characteristics or to add more infrastructure to compensate for them.

An ideal Data Center location is one that offers many of the same qualities that a Data Center itself provides a company:

• Protection from hazards
• Easy accessibility
• Features that accommodate future growth and change

These qualities are fairly obvious, like saying that it is easier for an ice chest to keep drinks chilled when it is also cold outside. Less apparent are what specific characteristics improve or hamper a property's usability as a Data Center location and why.

Building Codes and the Data Center Site

The first step when evaluating an undeveloped property's suitability as a Data Center site is a determination of how the property is zoned. Zoning controls whether a server environment is allowed to be built there at all. Zoning is done in a majority of countries and reflects how the local government expects a parcel of land to be used. Some classifications prohibit a Data Center.

Zoning information is maintained at the planning or public works department of the municipality whose jurisdiction the parcel is in. Many of these agencies even maintain their own websites and publish up-to-date zoning maps on them. Because land is frequently zoned in consistent blocks, a rudimentary way to estimate how a property is classified is to look at its neighbors. If the land is surrounded by private homes, it is probably residential. If the land is bordered by businesses or manufacturing, it is likely commercial or industrial. If the land is framed by open fields as far as the eye can see, it might be any of the previous zoning classifications or even agricultural land.

If a property you are interested in isn't zoned to allow a server environment, that doesn't mean you have to give up on the site. You can ask local government officials to rezone the parcel for a different type of use, although this might add time for them to review and approve your construction plans. As long as your construction project doesn't have a significant and negative impact on the surrounding area, it is likely to be approved.

Even if you are dealing with a developed site that contains existing structures, it is just as important to be familiar with the zoning, building codes, building control standards, and other government regulations (local, state, and national) that apply to the property. Ordinances vary significantly among cities, and even more so from country to country. They can regulate anything from how many hours a Data Center's standby generator is permitted to run per year to what time of day delivery trucks can travel through the neighborhood. Some countries even control the ratio of manpower and materials that can be imported, requiring that a project use a clear majority of in-country resources. Knowing the restrictions that apply to a given site enables you to either prepare for them or altogether avoid the location if you believe the rules aren't conducive to your business.

Site Risk Factors

Every parcel of land comes with unique hazards. Knowing the hazards associated with any property upon which you consider placing a Data Center is very useful and should be a serious consideration. Maybe the site is in a region known for earthquakes. Maybe it is in a flood plain. Perhaps it is close to an electrical tower that generates electromagnetic interference. Regardless of whether the dangers are naturally occurring or man-made, it helps to understand how they can affect a server environment, how to alter your Data Center's design to prepare for them, and who can provide information about whether a hazard applies to a particular property. In many cases, the local planning or public works department is an excellent resource. Your company can also hire a risk management firm to gather applicable hazard information about a site.

As you read the descriptions that follow about various hazards and the suggestions for how to mitigate their influence, keep in mind that the absolute best way to avoid a threat to your Data Center is by keeping it out of harm's way altogether. If a property has multiple risk factors, your company needs to decide if the merits of the site outweigh the cost of additional infrastructure to compensate for those hazards and the possibility that a colossal disaster can still overwhelm those preparations.

Natural Disasters

When considering risk factors connected to a property, most people think of natural disasters—catastrophes that devastate a broad geographic area. That's understandable. These events affect countless lives, do tremendous property damage, and garner significant media coverage. The following sections describe several that can threaten a potential Data Center location.

Seismic Activity

Earthquakes are caused when tectonic plates within the earth shift, releasing tremendous amounts of stored energy and transmitting powerful shock waves through the ground. The closer to the surface a shift occurs, the stronger the quake that is felt. Earthquakes are measured in two ways:

• Magnitude refers to its size, which remains the same no matter where you are or how strong the shaking is.
• Intensity refers to the shaking, and varies by location.

The most powerful earthquakes can topple buildings, buckle freeways, and cause secondary disasters, including fires, landslides, and flash floods—all extremely hazardous conditions that you want your Data Center to be well away from, or at least as insulated as possible against. Even a moderate quake that causes minimal property damage can tip over Data Center server cabinets, sever underground data cabling, or induce utility power outages.

Major earthquakes occur regularly around the world. Table 2-1 lists those of 7.5 magnitude or greater that have occurred just since the start of the 21st century, according to the United States Geological Survey.

Table 2-1. Recent Major Earthquakes

Up-to-date listings of earthquakes around the world, major and minor, are available at http://neic.usgs.gov/.

If your Data Center site is in an area known for seismic activity, the entire building should be designed to lessen earthquake impacts. Limit the planned heights of buildings, consolidate weight onto the lowest floors, and use high-quality building materials that can withstand shaking and won't easily catch fire. Anchor the building's structure to the foundation and use earthquake-resistant technologies such as steel frames and shear walls. Finally, limit the number of glass exterior walls and, no matter what architectural style is applied to the building, make sure that all balconies, chimneys, and exterior ornamentation are securely braced.

Similar earthquake mitigation should be applied within the Data Center itself, and more than one technique can be employed. One approach is structural reinforcement of all server and networking cabinets and their secure attachment to something immobile, by either bolting them directly to the Data Center subfloor or securing them with cables to anchor points set in to either the floor or ceiling. Alternatively, seismic isolation platforms can be installed below the cabinets. Bolting or tying the cabinets is intended to restrict their movement in a quake, whereas isolation platforms are to shift with an earthquake's motion, enabling the cabinets to surf over the movement and more likely stay upright.

Another good idea is the securing of all Data Center servers and networking devices by either tethering them with straps or directly mounting them to the cabinets. Miscellaneous Data Center supplies such as storage cabinets or tools should be tied down as well to reduce the number of objects that can become airborne in a quake. This both reduces the likelihood of injury to anyone in your Data Center during an earthquake and cuts down on how much debris has to be cleaned up once the shaking stops.

When choosing among earthquake mitigation options, be conscious of how they affect your Data Center's design. Bolting cabinets reduces the room's flexibility, for example, while installing seismic isolation platforms means server rows need additional buffer space around them so that the platforms can shift from side to side during a quake.

How do you find out if a site you are interested in is prone to earthquakes? Maps showing seismic activity are available at the planning or public works department local to the property. These agencies also have relevant information about the parcel's overall geologic makeup. Land consisting of bedrock, for example, is more stable and therefore more desirable in a seismically active area than land consisting of soft soil. Additional information about seismic activity, from what to do in an earthquake to where major quakes have occurred in the past, is also available through the United States Geological Survey, which you can find online at http://www.usgs.gov/.

Ice Storms

When weather conditions are right, freezing rain can blanket a region with ice, making roads impassable and triggering widespread utility power outages for hundreds of square miles or kilometers. These ice storms occur when relative humidity is near 100 percent and alternating layers of cold and warm air form. Unlike some natural disasters that occur suddenly and dissipate, severe ice storms can last for days. Because they cover a huge area and make it difficult for repair crews to get around, it can take several weeks for normal utility service to be restored to an area.

If your Data Center site is in a region susceptible to ice storms, operate under the assumption that the room might need to run on standby power for extended periods of time and that contracted services for refueling your standby generator, assuming you have one, might be unreliable. Consider this when deciding what tier of infrastructure to build your Data Center to. Additional battery backups or standby generators with greater fuel capacity might be in order.

Be aware that the wintry cold that contributes to an ice storm can itself threaten your building's infrastructure. When temperatures approach 32° Fahrenheit (0° Celsius), ice blockages can form within water pipes. High pressure then occurs between the blockage and an end faucet or valve, which can cause the pipe to burst. Because the liquid inside is frozen, a break in a pipe might go unnoticed until it thaws. Thoroughly insulate your building's piping and perform regular maintenance to reduce the likelihood of a burst pipe.

Local meteorologists as well as those in the planning or public works department can tell you if a property is susceptible to ice storms or freezing temperatures.

Hurricanes

Hurricanes, alternatively known in parts of the world as tropical cyclones or typhoons, are severe tropical storms capable of generating winds up to 160 miles per hour (257.5 kilometers per hour). (A tropical storm is not officially considered a hurricane until its winds reach at least 74 miles per hour [119.1 kilometers per hour].) Hurricanes form over all of the world's tropical oceans except for the South Atlantic and Southeastern Pacific. Although they do not start on land, powerful hurricanes have been known to come inland for hundreds of miles or kilometers before dissipating, causing widespread utility power outages and sometimes spawning tornadoes. Hurricane season begins in mid-May in the eastern and central Pacific basin and in June in the Atlantic basin, including the Gulf of Mexico and Caribbean Sea, and ends in November.

If your Data Center site might be in the path of a hurricane in the future, design the room without exterior windows. Transparent views into your server environment are not a good idea at any time, because they create an unnecessary security risk, and should especially be avoided should the building be struck by a hurricane. A hurricane's high winds can propel large debris through a glass window, even one that has been taped or boarded over.

Locate the server environment at the center of the building, if possible, and surround it with cement interior walls. If the Data Center must be near an external wall, surround it with a service corridor. All of your site's major infrastructure components should likewise be sheltered to withstand high winds.

Additionally, because hurricanes often cause power failures that last for days, design your Data Center with adequate standby power to continue functioning for that long. (Chapter 6, "Creating a Robust Electrical System," includes details about providing a Data Center with backup power.)

Besides high winds, hurricanes carry tremendous amounts of water. If a hurricane passes anywhere in the vicinity of your Data Center site, there is an increased chance of moisture entering the buildings there. For instance, external air vents on a building are typically oriented downward and covered with a protective lip. Although this is sufficient to keep out moisture from even a heavy rainstorm, a storm driven by hurricane winds projects water in all directions—including up into a downward-facing vent. Install additional barriers in the Data Center building to make it more water resistant. Consider having a subroof, for example, that can continue to protect the Data Center if a storm damages the main roof.

Hurricanes are unlikely to be a risk factor for a property if it is well inland. However, local meteorologists can tell you for certain if a property has a history of hurricane activity.

Tornadoes

A tornado is an intense rotating column of air. Created by thunderstorms and fed by warm, humid air, they extend from the base of a storm cloud to the ground. They contain winds up to 300 miles per hour (482.8 kilometers per hour), and can inflict great swaths of damage 50 miles (80.5 kilometers) long and more than a mile (1.6 kilometers) wide. Tornadoes can cause significant property damage, trigger utility power outages, and generate large hail. The most powerful tornadoes are capable of throwing cars and other large debris great distances, leveling homes, and even stripping bark off of trees.

If your Data Center site is in an area where tornadoes occur, it should be designed with the same safeguards as for a hurricane—avoid external windows on the Data Center and provide enough standby power systems to do without commercial power for extended periods of time.

Tornadoes can form any time of year. They occur predominantly in the United States, but are also known to appear in Australia and Europe. A portion of the central United States, roughly bordered east and west between the Appalachians and Rocky Mountains and north and south from Nebraska and Iowa to central Texas, is nicknamed Tornado Alley because of the high frequency of tornadoes. Local meteorologists can tell you if a property is susceptible to tornadoes.

Flooding

Flooding most often occurs because of torrential rains. The rains either cause rivers and oceans to rise dramatically and threaten nearby structures or else trigger flash flooding in places with non-absorbent terrain, such as pavement, hard-packed dirt, or already saturated soil. Although less frequent, flooding can also occur from a break in a dam or other water control system. Severe flooding can uproot trees and move parked cars, breach walls, and make roadways impassable. Flooding can also trigger utility outages and cause landslides.

If your Data Center site is in an area prone to flooding, make sure that the building's walls are watertight, reinforce the structure to resist water pressure, and build on elevated ground. If the property has no elevated ground, then consider building the Data Center above the ground floor. This keeps your company's most important equipment out of harm's way if water does reach the structure.

Placing the Data Center above the ground floor, however, affects other elements of the building's design. First, a building's weight-bearing capability is less on its upper levels than the ground floor. To compensate for this, either structurally reinforce the Data Center area or else accept significant limitations upon the acceptable weight of incoming server equipment. Current trends in server design are for more compact form factors that make for heavier weight loads, so in most instances reinforcement is the better option.

Second, if the Data Center is not on the ground floor, the building must have a freight elevator to accommodate incoming equipment and supplies. The elevator must be tall, wide, and deep enough to accept server cabinets, tape libraries, or pallets of materials. The elevator must also have the ability to support the equipment's weight as well as that of the pallet jack and people transporting them.

To find out if a property is located in a flood plain, contact the local planning or public works department. In the United States, flood plain information is also maintained at local offices of the Federal Emergency Management Agency (http://www.fema.gov/). The agency's Technical Services Division performs hydrologic and hydraulic analyses to identify flooding hazards in communities throughout the United States.

Landslides

A landslide occurs when a hill or other major ground slope collapses, bringing rock, dirt, mud, or other debris sliding down to lower ground. These flows can cause significant property damage, either in a single fast-moving event or gradually over time. Slides, also known as earthflows or mudflows, are propelled by gravity and occur when inclined earth is no longer stable enough to resist its downward pull. Earthquakes, heavy rainfall, soil erosion, and volcanic eruptions commonly trigger landslides.

If your Data Center site is in an area prone to slides, the environment should be designed with safeguards similar to those for flooding—make exterior walls watertight and strong to withstand sliding muck and debris and build on elevated ground. Other advisable practices are the construction of a retention wall or channel to direct flows around the Data Center building and the planting of groundcover on nearby slopes.

Parcels at the base of a steep slope, drainage channel, or developed hillside are more susceptible to landslides. Slopes that contain no vegetation, such as those burned by fire, are also more vulnerable to them. Trees, fences, power lines, walls, or other structures that are tilted on a site might be an indication of a gradual slide. Local geologists as well as those in the planning or public works department can tell you whether a particular property is vulnerable to landsliding.

Fire

Fires are the most common of natural disasters. They cause significant property damage, spread quickly, and can be started by anything from faulty wiring to lightning strikes to intentional arson. Even a coffee maker in a break room is a potential source of a fire. Large fires can span tens of thousands of acres and threaten numerous buildings. Even the act of extinguishing a fire once it has entered a structure can lead to millions of dollars in losses from water damage. Additionally, a fire that fails to reach your Data Center can still cause problems. Minor amounts of smoke from a blaze can clog the sensitive mechanisms within servers and networking devices, causing them to malfunction later.

The best ways to deal with fire in the design of your Data Center are prevention and early detection. Install fire-resistant walls and doors, smoke detection devices, and fire suppression systems, both in the Data Center and throughout the building. (Fire suppression system options for a Data Center are outlined in Chapter 8, "Keeping It Cool.") It is also desirable for the building to have adjustable dampers on its ventilation and air conditioning system. This enables you to prevent outside air from entering the server environment during a nearby brush or building fire.

Once your server environment is online, remove potential fuel for a fire by equipping the room with fireproof trash cans and prohibiting combustible materials in the Data Center such as cardboard. Be sure to keep brush and other flammable items cleared away from the building, too.

Although many causes of fires are unpredictable, the local fire department can tell you if a property has experienced wildfires in the past and where controlled burns are conducted in a region to eliminate unwanted brush.

Pollution

Just as smoke particles from a fire can interfere with the proper functioning of servers and networking devices, so too can other airborne contaminants such as dust, pesticides, and industrial byproducts. Over time, these pollutants can cause server components to short-circuit or overheat.

If your Data Center is built in a region where contaminants are present, protect your equipment by limiting the amount of outside air that is cycled into the room. The percentage of external air that must be circulated into a Data Center is normally controlled by regional building codes or building control standards. The ratios of internal and external air are based upon the size of the server environment and its expected occupancy. A Data Center that has personnel working in it throughout the day is typically required to incorporate more outside air than a Data Center the staff of which are in the room less frequently. Some municipalities even allow zero external air if no employees work throughout the day in the server environment.

A second method of protecting your Data Center is incorporation of high efficiency air filtration into the environment's air conditioning system. Be sure to schedule frequent and regular filter changes for all Data Center air handlers.

Some municipalities have an agency responsible for managing regional air quality that can provide information about known sources of pollution in an area. Pay special attention to this risk factor in areas known for strong winds, since they are more likely to kick up dust or carry contaminants a significant distance.

Electromagnetic Interference

Electromagnetic interference, or radio frequency interference, is when an electromagnetic field interrupts or degrades the normal operation of an electronic device. Such interference is generated on a small scale by everyday items ranging from cellular phones to fluorescent lights. Large sources of interference, such as telecommunication signal facilities, airports, or electrical railways, can interfere with Data Center servers and networking devices if they are in close proximity.

Electromagnetic interference is particularly challenging because it's not always easy to tell that your Data Center devices are being subjected to it. Even when that is known, you may not be able to immediately ascertain what the source of interference is. System administrators, network engineers, and others who work directly with the equipment are most likely to see symptoms first, even if they don't realize their cause. If you learn of a server experiencing unexplained data errors and standard troubleshooting doesn't resolve the problem, check around for possible sources of electromagnetic interference.

If your property is near an identified source of interference, locate the Data Center as far away as possible to limit the effects. All manner of shielding products—coatings, compounds, and metals; meshes, strips, and even metalized fabric—are available to block electromagnetic interference, but most of them are intended for use on individual devices rather than over a large Data Center. Again, distance from the source of interference is the best protection. That's because electromagnetic interference works according to the inverse square law of physics, which states that a quantity of something is inversely proportional to the square of the distance from a source point. The law applies to gravity, electric fields, light, sound, and radiation.

So, if a Data Center is located twice as far from a source of electromagnetic interference, it receives only 1/4 of the radiation. Likewise, if a Data Center is 10 times as far away, it receives only 1/100. To see an example of this effect, shine a flashlight (torch) against a wall. Back away from the wall, increasing the wall's distance from the light source (the mouth of the flashlight), and the circle of light against the wall becomes larger and fainter. Move closer, reducing the distance between wall and the light source, and that circle of light becomes smaller and more intense.

Figure 2-1 illustrates the inverse square law.

Figure 2-1 Inverse Square Law

The intensity (I) of electromagnetic radiation is inversely proportional to the square of the distance (d) from the source.

The local planning or public works department can provide the location of airports, railways, and other facilities known to produce electromagnetic interference.

Vibration

Servers and networking devices, like other complex and sensitive electronic equipment, are vulnerable to vibrations as well. As when dealing with electromagnetic interference, there are several commercial products available to inhibit vibrations from reaching Data Center servers—from springs to gel-filled mats to rubber mounts—but the most effective solution is simply avoid locating your Data Center near large vibration sources. Airports, railroads, major thoroughfares, industrial tools, and road construction are common sources of vibrations.

The local planning or public works department can provide information about what major road construction is scheduled to occur near a property, as well as which of these other facilities are in close proximity.

Political Climates

Among the most challenging risk factors to diagnose and prepare a potential Data Center site for are the man-made kind. Political instability in a region can delay the delivery of Data Center equipment and materials, make utility services unreliable, and—worst of all—threaten the safety of employees. Depending upon how contentious conditions are, workers of certain nationalities might even be prohibited from traveling into the region.

When dealing in an area with conflict, adjust your Data Center project timelines to accommodate delays. Design the server environment itself with standby power systems to support the room if utility services fail. Reinforce building walls to withstand explosions. Install safety bollards around entrances and any external infrastructure, such as generators, to protect against someone ramming a vulnerable area with a car or truck. Consider placing security fencing around the entire site. To find out whether or not a property is in a politically unstable area, check with the local embassy and news outlets. The United States Department of State, Bureau of Consular Affairs (http://travel.state.gov/) issues travel warnings for known trouble spots, as do the consular offices of most countries.

Flight Paths

If there's an airport in the region of a potential Data Center site, be aware of the flight paths that incoming and outgoing planes regularly follow. Although crashes or debris falling from aircraft are rare, the effect can be devastating if something does strike your Data Center.

How should you prepare for this unlikely event? Even if your property lies in the path of a busy airport, it is probably not cost effective to make your Data Center an impenetrable bunker. A more practical solution is to distribute your servers. Build two smaller server environments and place them in separate locations, even if just two different buildings on the same property. As unlikely as it is for your Data Center to be struck by an out-of-control plane, it is that much less likely for two rooms to suffer the same fate.

The local planning or public works department can inform you if a property is in the flight path of any local airports.