In data center terms, what is "white space"?

The data hall floor area where IT racks and servers are installed

The electrical and mechanical rooms that support the IT equipment

Land on the campus held for future expansion

Empty rack units left open inside a cabinet

What is an edge data center?

A smaller facility placed close to users or devices to cut latency

The largest building on a hyperscale campus

A facility built at the edge of a city to avoid zoning rules

A standby site that is used only during disasters

What is the main job of a UPS (uninterruptible power supply) in a data center?

Conditioning power and carrying the IT load from stored energy until generators take over

Stepping medium-voltage utility power down to 480 V for the building

Switching the building from utility power to generator power during an outage

Measuring how much energy each rack uses so customers can be billed

Which equipment cools the data hall by blowing room air across a chilled-water coil?

A computer room air handler (CRAH)

A power distribution unit (PDU)

An uninterruptible power supply (UPS)

An automatic transfer switch (ATS)

How is Power Usage Effectiveness (PUE) calculated?

Total facility energy divided by IT equipment energy

IT equipment energy divided by total facility energy

Cooling energy divided by total facility energy

IT equipment energy minus cooling energy

In a hot aisle/cold aisle layout, how are the rack rows arranged?

Rows alternate so fronts face fronts across a cold aisle and backs face backs across a hot aisle

Every row faces the same direction, so each row exhausts into the next row's fronts

Racks face the cooling units, with servers mounted sideways in the cabinets

Hot and cold racks alternate within each row to even out temperatures

What happens in a meet-me room?

Carriers and customers connect their networks to each other with cross-connects

Visitors sign in, show ID, and receive badges before entering

Operators watch alarms from every building system around the clock

Customers meet sales staff before a tour of the facility

In a typical retail colocation data center, who owns and maintains the servers inside a customer's cage?

The carrier in the meet-me room

Quiz · Data Center Basics

Data Center Basics Quiz

Ten beginner questions on what a data center is, how it is laid out, and the equipment that keeps it running. Each answer comes with a short explanation.

10 questions About 5 minutes Beginner

Question 1In data center terms, what is "white space"? The data hall floor area where IT racks and servers are installed The electrical and mechanical rooms that support the IT equipment Land on the campus held for future expansion Empty rack units left open inside a cabinet

Show answer
Answer: the data hall where IT equipment lives. White space is the raised floor or slab area that holds racks, cabinets, and cages. The switchgear, UPS, battery, and mechanical rooms that support it are often called gray space. Read What Is a Data Center?
Question 2What is an edge data center? The largest building on a hyperscale campus A facility built at the edge of a city to avoid zoning rules A smaller facility placed close to users or devices to cut latency A standby site that is used only during disasters

Show answer
Answer: a smaller facility close to users or devices. Edge sites put compute near where data is created or used, such as a metro area, a factory, or a cell site, so round trips are short. They are often remotely monitored and connect back to larger regional or hyperscale facilities. Data Center Design Fundamentals compares facility types.
Question 3What is the main job of a UPS (uninterruptible power supply) in a data center? Stepping medium-voltage utility power down to 480 V for the building Switching the building from utility power to generator power during an outage Measuring how much energy each rack uses so customers can be billed Conditioning power and carrying the IT load from stored energy until generators take over

Show answer
Answer: conditioning power and bridging to the generators. The UPS filters disturbances and, when the utility fails, carries the load from batteries or a flywheel for the seconds to minutes generators need to start. Transformers step voltage down, and a transfer switch moves the building to generator power. Read how UPS systems work.
Question 4Which equipment cools the data hall by blowing room air across a chilled-water coil? A power distribution unit (PDU) A computer room air handler (CRAH) An uninterruptible power supply (UPS) An automatic transfer switch (ATS)

Show answer
Answer: a CRAH. A CRAH uses fans and a coil fed with chilled water from the central plant. Its cousin, the CRAC, has its own refrigerant compressor, while a PDU distributes power to the racks. Read the cooling guide.
Question 5How is Power Usage Effectiveness (PUE) calculated? Total facility energy divided by IT equipment energy IT equipment energy divided by total facility energy Cooling energy divided by total facility energy IT equipment energy minus cooling energy

Show answer
Answer: total facility energy divided by IT equipment energy. A PUE of 1.0 would mean every kilowatt-hour reaches IT equipment, and a site at 1.5 spends 0.5 kWh on cooling, power losses, and lighting for every kWh of IT. The inverse, IT energy over total energy, is called DCiE. Read the PUE guide.
Question 6Which Uptime Institute Tier is defined as "concurrently maintainable"? Tier I Tier II Tier III Tier IV

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Answer: Tier III. Concurrently maintainable means any component or distribution path can be taken out for planned maintenance without shutting down IT. Tier IV adds fault tolerance, so a single unplanned failure does not affect the load either. Read the Tiers guide.
Question 7In a hot aisle/cold aisle layout, how are the rack rows arranged? Every row faces the same direction, so each row exhausts into the next row's fronts Rows alternate so fronts face fronts across a cold aisle and backs face backs across a hot aisle Racks face the cooling units, with servers mounted sideways in the cabinets Hot and cold racks alternate within each row to even out temperatures

Show answer
Answer: fronts face fronts, backs face backs. Servers pull cool air in the front and exhaust hot air out the back. Facing the rows this way keeps cold supply air in one aisle and hot exhaust in the next, so the two streams mix less. Data Center Design Fundamentals covers white space layout.
Question 8What happens in a meet-me room? Visitors sign in, show ID, and receive badges before entering Operators watch alarms from every building system around the clock Customers meet sales staff before a tour of the facility Carriers and customers connect their networks to each other with cross-connects

Show answer
Answer: carriers and customers interconnect. The meet-me room (MMR) is the interconnection hub of a colocation or carrier facility. Network providers terminate their fiber there, and a cross-connect cable links a customer cage to a carrier or to another customer. Fiber Optics & Network Cabling covers the cabling side.
Question 9A data hall needs four cooling units to carry its full heat load. The design installs five. What is that redundancy called? N N+1 2N 2(N+1)

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Answer: N+1. N is the capacity the load needs, here four units, and one extra unit makes N+1, so any single unit can fail or be serviced. A 2N design would install eight units as two complete sets. See the redundancy table.
Question 10In a typical retail colocation data center, who owns and maintains the servers inside a customer's cage? The customer The colocation provider The electric utility The carrier in the meet-me room

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Answer: the customer. A colocation provider sells space, power, cooling, physical security, and connectivity, while customers bring and manage their own IT equipment. Many providers also offer "remote hands" for simple tasks. Data Center Operations Management covers how the facility side runs.