Server Room Designs

When designing a server room or even an entire data center, it's best to keep things as simple as possible. The smaller the number of components you introduce into your server room, the easier it is to design. If you can standardize on a particular raised flooring standard, or a particular size and type of server rack, or a particular standard of HVAC (heating, ventilation, and air-conditioning) system, you can design your entire space in a consistent and easy-to-understand manner.

If you can control your design so that you build sections in modules, when you need to expand your capacity, it is often a simple matter of adding another module. Simplicity has many benefits. When you use fewer system types, the number of spare parts you have to keep on hand also drops. Fewer systems also means that you can afford to have a smaller support staff to administer them.

Unfortunately, many server rooms, particularly smaller ones, aren't designed with servers in mind. Smaller server rooms tend to be designed to fit the equipment that is already on hand. Even if you aren't constrained to a small server room, it still behooves you to take a minimalist approach to the range of new equipment you adopt because you generally already have the expertise to run and manage the equipment you have.

Most larger server rooms are designed and built by companies that specialize in this sort of construction. Whatever company you hire to construct your server room, you need to check it out just as you would any other company that does a big project for an organization. That means that you should check references, visit sites to see their past work, and have the work monitored. Building a server room is a lot like building a house: It requires many different skills to construct the systems in the room, and rarely does one company do it all. For most designs and construction, a consultant or consulting firm should act as the general contractor for the work. Whatever design you end up selecting, there should be a project specification document that details the design, sets milestones, and provides oversight.

Chances are that whoever you choose to be your primary contractor, if your server room is large or if you are designing a data center, your contractor may be managing the following types of experts:

• Architects To draw the building or room.

• Structural engineers To evaluate the building's qualities and determine structural parameters, such as floor carrying capacity.

• Electricians To manage the placement of power lines, install distribution panels and conduit, run wiring, and set up fire and smoke alarms, as well as power backup systems.

• HVAC specialists To design and install an HVAC system, including the HVAC plant equipment, and run and return piping, heat exchangers, and other related equipment.

• Interior designers To select furnishings consistent with the purpose of the room(s).

It's rare that any one firm has all these skills in-house. As part of the design phase, you should expect to get a set of CAD drawings with associated financials and time lines that provide a roadmap to the construction phase of the project.

Of course, in the spirit of the 21st century, if you are creating a small server room, you can play all the roles yourself.

Converting Existing Rooms to Server Rooms

In many cases server rooms aren't new construction. A server room may start out as a classroom, a stockroom, a laboratory, an office, an anteroom, or something else. Just about any kind of room can be converted into a server room. This isn't a planned process, like starting from scratch designing a large facility is; it's growth by happenstance. It might begin with the arrival of a single server, and soon, without any planning at all, you might find several servers, storage arrays, and all sorts of systems.

When does a room become a server room, and when does it cease being any other kind of room? You have a server room when the following are true:

• The room needs air conditioning to keep it cool.

• A 220V electrical line needs to be wired into the room.

• You put a special lock on the door.

• You put a surveillance camera in the ceiling.

• You try to move large pieces of equipment from another part of the building into the room.

• Your first thoughts during a hurricane are to rescue the backup tapes in the room.

If you are lucky, you get to choose which room becomes a server room. Part of the planning has the site accommodate the necessary infrastructure to make your job easier. If there is no selection process for the room and you take what you can get, then you must retrofit your facility in order to have the infrastructure accommodate the site. It is typically true that accommodating a site is more difficult and more expensive than planning a site. Let's look first at a room selected by choice and then consider a retrofit project where you have no control over the site.

When you are offered a choice of rooms that can be used as a server room, it is best to draw up a list of characteristics that you need in your ideal server room. You can then rank each room as to how well it offers each of the properties a good server room should have. Here's a partial list of desirable characteristics:

• Good location for managing security issues

• Adequate access to loading docks or elevators

• Preexisting electrical and telecommunications infrastructure

• Adequate or extensible HVAC capabilities

• Ability of the room to carry the physical load (weight imposed)

• Protection from water damage, earthquakes, or other natural disasters

This list isn't much different from what you would use in the design process for a complete data center, but it is scaled down and weights each of the factors in a different way. In order to convert a specific room to a server room, you may find that you have to compromise on one of the characteristics that is desirable. It may be that in order to get the appropriate wiring, you will not be able to use a room near an elevator, for example. However, with planning, you can maximize your server room's capabilities while minimizing the overall cost.

Now let's look at an instance in which you have no control over the room, its location, or any of the other characteristics or properties of the room. In this case, you should create a document that lists the room's facilities: electrical, HVAC, and so forth. That document should then detail the equipment you are going to put into the server room, as well as equipment you want to eventually add. After you specify the equipment, you can then determine the facilities that will have to be added to the room to support the equipment.

The main problem with ad hoc placement of equipment is that in most instances, when the equipment grows to a certain point, it ends up getting relocated. The reason for this is simple: It becomes cheaper to relocate than it does to invest in some needed requirement. You don't want to be in a situation where you've made major investments getting a room ready to be a server room only to find out down the line that the investments were a waste of money. By specifying what you need to support what you intend to use, you can balance cost and a time line so that your server room gives you a strong return on investment. In other words, with some thought and planning, you can maximize your server room's utility while avoiding making unadvised investments in infrastructure.

Server Closets

All mechanical devices make noise. Some, such as dot matrix printers, make a lot of noise. Given that it's possible to build a small data center into a rack and put that rack into an enclosed space, you might want to consider whether that's really a good idea.

Many companies start by building a server rack that they maintain in their office. As the rack gets more fully populated, it gets more valuable and noisier, and it needs more physical protection. For these reasons, companies consider moving their racks into small, enclosed spaces. It's not a new idea: For many years, network connection patch panels and junction boxes have been located in closets. Moving a server or set of servers into a small space is along the same lines.

Unlike with a closet for switching equipment, the main problem for a server closet is environmental control. You don't have to condition a server closet so it can be habitable by people, which lessens the HVAC requirements you might otherwise have. The main HVAC requirement is that your equipment operate in a certain temperature range, and that sets your HVAC thresholds.

Server Room Specifications and Considerations

The design specifications for your server room are where your requirements meet your budget. Your design may be determined by the scope of the capabilities that need to be established; but your ability to add additional redundancies, establish different services, and support maintenance contracts is constrained by the budget you have to build the room as well as the budget you have to support it. Because no one ever has all the funds needed to build everything desired, it's important to make the right set of compromises.

In considering the compromises, you need to try to determine the answers to the following questions:

• Can you start with a subset of your desired installation and complete the plan later on?

• What systems are essential, and what systems are optional?

• How much fault tolerance (provided by redundancy) is desirable, and how much can you afford?

• Does your budget support your project scope, and is there enough flexibility to reassign funds, if needed?

• Does your design leave room for expansion and upgrading?

• Does your server room's annual operating budget support the required number of staff and services?

Perhaps the best investment you can make in designing a server room is to write a formal project specification document. The money you spend planning your building will likely be returned several times over, in the form of less waste and more user satisfaction. Indeed, in any large project, the specification document is considered to be the first phase of the work.

Determining Location

The first step in designing a server room is to site it. In many instances, you don't have control over where you locate your servers, but when you do, there are a number of criteria you can apply to choose the best location. Selecting a location is a balance between cost, convenience, and availability, and your choices should be influenced by the server room's purpose. For network systems that just can't go down, considerations such as network, power, and environmental services may be the deciding factors in choosing a location. When you can tolerate some downtime, you might choose to pick a location with a lower cost.

It's useful to create a matrix of your server room's design elements (as rows), and rank them against each location (the columns). In addition, you should have two columns that estimate your expected installation cost as well as your yearly projected budget for each component. A spreadsheet of this type can really help you decide on a site and other design elements. You might want to develop this document as part of your preliminary thinking or assign it as part of the initial design specification part of your project.

Macro-Level Location Concerns

As the cliché goes, location, location, and location are the three primary factors that offer success in the real estate business. Location also matters when you are determining where to place your server. You certainly wouldn't want to place your server room directly over an active earthquake fault, in an area that floods, or high up in a tall skyscraper. These are all locations with obvious issues that can cause you significant trouble. However, there are ways to deal with these kinds of difficult environments:

• In a seismic zone, at the very least, you can expect vibrational tremors, and you need to constrain all movable items to something solid, using mounting devices. If you build a server room in an earthquake zone, you might make the decision not to use a raised floor, under the assumption that a solid floor offers a better and more secure foundation for your equipment.

• A server room in a tall building also has concerns regarding sway and vibration. Your main concern for a server room located in a tall building might be access. Unless there has been adequate planning done in the construction of the building, it may be difficult to route a cable from one part of the room to another or from one floor to another.

• A flood zone construction may require that you place your server room significantly above historical flood levels in a building, have adequate pumping capabilities, and locate your wiring above the server room (rather than underneath it). You might also have to design your facility to be sealed in a way that prevents water or moisture from intruding.

No one would prefer to locate their equipment in areas such as these, but if you go to San Francisco's West Bay area, New York City's Wall Street, or downtown New Orleans, you will find many companies running server rooms in those areas. You'll also find that with advanced network connectivity, many of those same types of firms choose to locate their data centers miles away, in less problematic and more cost-effective locations.

Micro-Level Location Concerns

The macro-level concerns about where you locate a server room have micro equivalents that should guide your choice for the location of your server room.

A server room should be centrally located in a building, to minimize the amount of cable necessary to connect to other systems in the building. A central building location also has the least temperature and humidity fluctuations. If your server room is on the outside of the building and surrounded by large glass windows, hot temperatures and sunny days or cold temperatures mean that you have to be more careful about cooling and heating the room.

You don't want your server room to flood, so putting a server room in a basement or the ground-floor level of a building isn't as good an idea as moving the room further up in the building. Coastal regions and the effects of global warming aside, the most common way to flood a server room isn't from a nearby body of water flooding its banks; a flood is most likely to be the result of a water pipe bursting. Therefore, you need to eliminate all runs of piping through the server room or in the ceiling above it. If the floor above has a bathroom, then undoubtedly there are water pipes leading into it. Either the bathroom or the server room should be moved. Water and electricity are not a good combination. At the very least, if you can't move piping away from your server room, you should plan for disaster by installing a water barrier on the ceiling of your server room. This water barrier is usually a curtain or an impermeable plastic material that can route water away from your room and equipment, a little like a horizontal shower curtainalbeit a lot bigger. In humid climates, a good vapor barrier should also be installed.

Note

You can find a list of companies that provide waterproofing materials at www.thebluebook.com/cl/stall4670.htm.

Another location consideration is security. Some locations lend themselves better to being protected than others. If your server room is near areas with a large amount of foot traffic, it is harder to secure the room than it would be if it were located in an area where fewer people are located. Lobbies, common rooms, cafeterias, and auditoriums are areas that get a lot of traffic and are unsuitable neighbors for a server room.