Building a Data Center: How to Understand Tier Classifications

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

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

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

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

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

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

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.