• A centralized location where computer
related resources (and data) are stored.
• The users do not require physical access in
order to use the resources.
• A room
– Interior room
• A section of a building (a floor)
– Interior building space
• A building, underground structure, etc.
• Ease of access to roads
• Ease of access to the interior
Large oversized double doors
• Geography, weather, and climate
Data Center Requirements
Weight rated floor
Access to power
Access to HVAC
– Limited access entry points.
• Crime prevention through environmental
Fences, walls & gates
Natural barriers and open spaces
• The computer room should have limited
access: on a need to be there basis only.
– Keycards and old fashioned keys and locks.
– Guests should not be given access without an
– Proximity badges
– Biometric Passes
– A room may require two people to have access
at any one time, so no one can be alone in the
Physical Security: Surveillance
• Cameras (Closed Circuit Video)
• Motion Detectors
• Keeping track of entry and exit of each individual
• Your power capacity must provide for
• As technology advances, it takes less space to use
equal amounts of power.
• Power cords, fuse boxes, switches must meet fire
safety standards. (NEBs Standards)
• Networking Equipment Building System
Temperature & Humidity
Electric safety standards
Power Main Categories
• Surge Protection
• Line conditioning
• ATS (automatic transfer switch)
• Fire codes require an off switch for UPS.
• May include generators for prolonged
Automatic Transfer Switch
• Detects when utility power is outside of an
acceptable range, then activates the UPS
• Detects when utility power resumes, and
switches from UPS to utility power.
• UPS must provide power for
– Computing systems and other essential
– Separate backup power for any fire suppression
• UPS may require special requirements for:
Its own special room
• Make sure the power is available for this room too!
• Access is for maintenance and inspection only!
• UPS can be made up of a room full of
– these can be a dangerous fire hazard.
– Fumes from battery acid are flammable and
• Statistics show that power outages tend to
last for very short periods or very long
• Most power outages last less than 5
• If an outage lasts more than 10 minutes, it is
likely to last all day.
• A UPS should have enough stored power to
last about 10 min + the required time to
• A generator would be required to handle
power outages lasting more than 10 to 15
• UPS needs maintenance. Rechargeable lead
acid batteries will last about 5 years.
Power: Surge Protection
• Required to protect against jumps in voltage
from your power source.
• Can happen when there is a sudden large
draw of power. Most likely to happen
during power outages.
• A spike in voltage can damage electronics.
Power: Surge Protection
• Data center should be grounded for
lightning strikes using lightning rods.
Power: Line Conditioning
• A power conditioner keeps the power
supply at a constant voltage and frequency.
• Deals with sags, spikes, surges, and
– Surges last longer than spikes.
• A step above surge protection.
Power: Fire Suppression
• Fire suppression power requirements must
be separate from everything else including
computer system UPS.
Halon Alternatives are used to reduce the oxygen
content. (There must be enough remaining
oxygen for humans to breathe)
CO2 – cheap but causes greater condensation
compared to other alternative suppressants.
If fire suppression is activated:
Power down systems.
Shut off all power and system UPS
Contact the suppression experts
Maintain a fire-evacuation plan
• Fuse boxes, and any other power switch
control should be easily accessible and not
hidden behind equipment.
• Heating Ventilation and Air Conditioning
• Fans for forcing air flow
• Filters for reducing the amount of
contaminants in the air.
• Humidity control –
– dry air leads to more static electricity.
– Damp air leads to corrosion
– 40%-60% RH
• Water chillers, pumps, compressors
HVAC: Air Flow Management
• The hot aisle-cold aisle alternating system
• Room should have good ventilation.
• Equipment should be spaced apart to
prevent heat pockets from forming.
• The Amundsen-Scott facility does not
require heating as long as the equipment in
the data center is running.
• Water sensors should be placed under AC
units, and raised floor.
• Multiple thermostats may be required for
• Alarm to alert when temperature/humidity
is outside a safe operation range.
• Floor Layout
• Racks help manage space efficiently.
• Racks are needed so that equipment is not
literally stacked on top of each other. (build
up of heat)
• Racks also provide cable management.
• Racks help manage HVAC
• Two Posts – usually for lighter
• Four Posts – for heavier hardware.
• Height – should not be too tall that access is
difficult or gets too close to the roof. Heat
rises and equipment at the top will be
subject to higher temperatures.
– Computer hardware standard is 19 inches.
– Networking hardware NEBS standard is 21
inches. Network Equipment Building
Must be deep enough for your equipment to fit
plus enough space for vertical and horizontal
Cables and equipment should not protrude into
aisle space. (check fire codes)
• Extra deep racks tend to create unused
– Over packed racks lead to cabling
complications and heat build up around
• Some racks have built in fans.
• Bottom mounted fans may require perforated
• Bottom mounted equipment can restrict air flow.
• Doors on racks restrict air flow when closed.
• Allow racks to be far enough apart for easy
access to equipment and cabling.
• Racks placed too close will build up
excessive heat and cause access problems.
Racks: PDU vs Power Strip
• PDU - power distribution unit connects
different sockets into different circuits.
• Not all equipment is rack mounted.
• Be sure to have enough space for non-rack
– Networking cables
– Hardware connection cables
• Heavy power cables are best suited for
under the raised floor.
• Cable tracks hang from the ceiling. They
are designed to handle both power and data
• Lighter data cables can be above the drop
• Keep power cables and data cables as far
apart as practical.
– EMF from power cables can adversely effect
data cable performance.
• In some instances, the floor may collect
water and not be ideal for power cords.
• A leaking roof is also problematic.
• Water sensors should be installed under a
raised floor near the AC units.
• Use twist ties to keep cables in place.
• Put labels on both cable ends. Color coded
strips are ideal.
– Consider what will happen if you unplug the
wrong piece of equipment.
• Data and power cables should be color
– Thick black and gray cables are usually power
– Networking cables are often red, yellow, blue,
• Collect cables in different lengths. Try to
use cables of the correct length to avoid
large cable loops.
• If cables are too short, maintenance on
hardware is more difficult.
• Use plastic twist ties for bundling similar
• Don’t bundle power and data cables.
• Wire the data center for different AC power
• Create different pathways for cables. In
other words not all cables should go through
the same path. If a path is submerged in
water or on-fire, you want alternative
Power cords at both ends.
Data cables at both ends.
– Disk drives
– Tape drives
– Servers Front and Back
• High port density equipment is difficult to
label. Be creative with your labels.
• Some cables are molded with labeling on
Data Center Communications
• Data centers are noisy due to fans, disk
drives, and the AC. Phones are hard to use.
• The data center is not a good environment
for working at a console.
– Too noisy
– Insufficient space
– To many servers to have individual consoles for
– Tends to be cold and drafty
• Keep a minimal number of consoles in the
• You want to discourage unnecessary
console usage in the data center.
• Use a switch box for accessing the
• A laptop computer or serial console can be
placed on a moveable cart. The cart can be
positioned and connected to any server.
• Should be grounded.
• Grounding wrist bands should be attached
to the bench.
• Should have multiple power sockets.
• Should be in close proximity to the data
• Work rooms generate dust and should not
be in the data center.
• It is very difficult to keep track of tools.
Tools are borrowed and never return.
• Consider using an inventoried tool box and
• The best tool box has drawers in a cart.
• Miscellaneous things to have:
– Vacuum cleaner
– Brooms and brushes.
Keep spare parts in a special area.
Use bins or drawers to organize.
Cables of different types and lengths.
Anything else you can’t afford to do
• Network Equipment Building System is the
documented standards for
Room space planning
Temperature and humidity
Acoustic noise levels
Electrostatic discharge immunity
DC potential difference
• Used by the telecommunications industry.
• Creates high reliability standards.