The following tip was excerpted from Chapter 4, 'Data Center Design,' from the book Administering Data Centers: Servers, Storage, and Voice over IP by Kailash Jayaswal, courtesy of Wiley Publishing. Click here for the complete collection of book excerpts.
When designing a data center, plan ahead. New factors unfold and must be resolved before starting the construction phase. Keep the design simple. It is easy to set up and manage. Root causes of problems are easy to identify and resolve.
Following are some hints:
- The design must be modular— Use patch panels for Cat5 and fiber connections. Segment the data center with sets and keep them independent of each other. Each set must have its infrastructure equipment in a single rack called the point of distribution (POD).
- Label everything— This includes ports, cable ends, and devices. Also, label the physical grid locations in the data center. If the north-south side is labeled with alphabets, the east-west side must be labeled as numbers.
- Document everything—This includes device details, location, and software components. Equipment location in the data center must be documented online.
- Isolate cables— Keep all cable bundles either in the subfloor plenum or ceiling plenum. ■
- Use cast aluminum tiles— They are strong and will be able to handle increasing weights of future equipment and densely packed racks.
Data-Center Design Case Studies
This section discusses data-center design cases. The process of determining the requirements and final suggestions must be changed for other situations.
Celebrity Travels is a full-service travel agency that must keep all its data online. It also provides travel- and vacation-related services to several other agencies. It has recently acquired Castro Services, another long-established travel agency. Celebrity Travels wants to provide independent travel agents with the ability to use Celebrity's reservation system remotely for a certain fee.
Because of shrinking profit margins, Celebrity Travels has decided to reduce expenses. Most of its 400-person workforce operate out of their homes, anyway, and have no need to visit the data center. The only people who must physically work at the data center are the NOC, equipment installers, and maintenance and security personnel. Celebrity Travels has decided to relocate its data center from Boston to Kansas, where space and local help are far less expensive.
The company has purchased a large plot of land for its data center. It engages a data-center design consultant from the beginning to plan all the details. Unknown future expansion plans require the need for a flexible and scalable design that must provide high availability and servicing without equipment downtime.
The consultant must make final determination regarding all aspects of the design and construction of the data center including size, raised floor design, rack layouts, HVAC systems, UPS, generators, electrical and mechanical distribution, fire suppression and detection, and network and electrical cable design.
The consultant determined the approximate base load of the equipment in the proposed data center and suggested a raised floor design. The floor area was divided into functional areas such as NOC area, equipment staging area, network room, and data center area, which would have rack rows containing servers, storage, and other devices. Some floor area near the entrance was marked for large floor-standing servers and storage subsystems (which are not designed for racks).
The consultant suggested a redundant three-phase UPS system and power distribution unit, backed by a diesel generator. The generator was located just outside the data center with exhausts facing away from the building. For redundancy, the data center had two power feeds from different grids. The HVAC unit was designed to be redundant. It had two units and subfloor air distribution systems.
The return-air ducts were located in the ceiling plenum. The two units were located on diagonal sides of the data center. The electrical and mechanical infrastructure was designed in such a way as to be able to double the amount of UPS protection and precision cooling seamlessly should it become necessary.
The network room had switches connecting the servers to the intranet and ISPs. The racks in the data center were grouped into sets.
Each set of racks had POD racks that contained patch panels, terminal servers, and subswitches. The POD patch panels were connected to the patch panel in the network room. The fire-suppression system included a preaction sprinkler system, smoke detectors at various locations and plenum areas, and temperature-based fire-sensing devices.
The entire data-center construction project took 8 months from concept to completion. The close cooperation and partnership of all critically involved parties (such as the customer, engineers, and contractors) was vital to the accomplishment of the overall project.
Designer Dresses, Inc., has several off-line stores around the state. The owners have decided to establish an online presence to be able to allow anyone in the country to order dresses. They have acquired services from a software development firm to place their catalog online. They have rented a building in the state of New York.
Designer Dresses has engaged a data-center consultant to architect and build a 1,000-server data center that must have no downtime for network devices, servers, or any facility services (such as power and air conditioning).
The data center was architected with raised floor. There were two redundant HVAC units and subfloor plenum chilled-air distribution. Two separate power feeds came from different utility companies. Two 50-kilowatt three-phase UPS units with 30-minute batteries backed the grid power, which, in turn, were backed by diesel generators.
Separate areas were allocated for different functions (such as NOC, loading area, network room, and racks). All the devices in the data center were designed for racks. However, a part of the data center had no racks and would be used for future, nonrackable equipment. The rack rows were laid out, along with hot and cold aisles. Only cold aisles had perforated tiles. The equipment had front-to-back cooling, and each rack front faced a cold aisle.
Following are some key points discussed in this chapter:
- It is important to get the design right because retrofitting a data center is too expensive and unwieldy.
- A data-center design must be simple to modify and manage, scalable to accommodate future needs without any changes, and modular and flexible so upgrades can be made if necessary.
- Common structures within a data center are raised floor, aisles, floor tiles, subfloor plenum and ceiling plenum, electrical wireways, and cable trays.
- All equipment, cable ends, and grid locations must be labeled in an orderly manner.
The previous tip was excerpted from Chapter 4, 'Data Center Design,' from the book Administering Data Centers: Servers, Storage, and Voice over IP by Kailash Jayaswal, courtesy of Wiley Publishing. Click here for the complete collection of book excerpts.