Arnie W. Evdokimo is chief executive officer of DP Air Corporation, a leading provider of data center design, build and maintenance services based in Phoenix. For more information about Building a Data Center, visit http://dpair.com/design-data-center/today.

1. Building a Data Center:
How to Understand Tier
Classifications

2. Building a Data Center
• Four data center tier classifications exists,
from basic Tier I to rigid Tier IV
• Balance the need for availability with the cost
of redundancy – higher tier level, means
greater availability but at more cost
• Objectively identify performance levels
• Tier classification involves operation of the
data center as a whole

3. Building a Data Center
Tier I - Basic Site Infrastructure
• Has non-redundant capacity components and
single, non-redundant distribution path
• Things to know about building Tier I
– Planned work will require all systems shut down
– Planned and unplanned disruptions will affect
availability of computer equipment
– When preventive maintenance and repair occurs,
data center infrastructure must be on complete
shut down

4. Building a Data Center
Tier II - Redundant Site Infrastructure Capacity
Components
• Have redundant capacity components and
single, non-redundant distribution path
• Things to know about Tier II
– No computer shut down required for removal of
redundant capacity vs. System shut down
required for removal of distribution paths
– Unplanned and planned work will affect data
center availability

5. Building a Data Center
Tier III - Concurrently Maintainable Site
Infrastructure
• Have redundant capacity components and multiple
independent distribution path. All IT equipment must
be dual-powered
• Things to know about Tier III
- Elements and components can be removed from service
without impacting computer equipment
- Sufficient and permanently installed capacity exists
- Unplanned activities can disrupt computer equipment
- Available alternative power sourcevv

6. Building a Data Center
Tier IV -- Fault Tolerant Site Infrastructure
• Gauranteed highest levels of availability
• Most rigid category – hosts mission critical
compartmentalized systems, redundant
subsystems, compartmentalized security and
strict security control methods
• Things to know about Tier IV
– Fault tolerant data center. Power and cooling
maintained after infrastructure failure

7. Building a Data Center
Tier IV -- Fault Tolerant Site Infrastructure
• Things to know about Tier IV
– Failures within will not affect computer
equipment.
– Sufficient capacity exists, no planned or
unplanned activity can disrupt site
– Engine-generator is primary power source.
Available alternative power source

8. Building a Data Center
About the Author
Arnie W. Evdokimo is chief executive officer of
DP Air Corporation, a leading provider of data
center design, build and maintenance services
based in Phoenix. For more information about
Building a Data Center, visit
http://dpair.com/design-data-center/today.