Uptime Institute encountered the following Tier Myths and Misconceptions, published on 24 March 2010, during recent site visits in Latin America, Europe, Russia, Africa, and Asia. These myths have taken attention away from the fundamental concepts of the Tier Classification System. The result has been shortfalls in design topology despite adequate budgeting. These shortfalls put the data center's ongoing uptime at risk. Although encountered more often internationally, the myths below have also been noted in North America.
Myth: TIA-942 is a guideline for Uptime Institute Tiers.
Uptime: The similarities between the Uptime Institute Tiers and TIA-942 stop at the surface. Uptime Institute Tiers is functionally disconnected from TIA-942. The core objective of Uptime Institute Tiers is to guide a design topology that will deliver high levels of availability -- as dictated by the owner's business case. Uptime Institute Tiers evaluates data centers by their capability to allow maintenance and to withstand a fault. Uptime Institute Tiers is not available in checklist form. To avoid further confusion, Uptime Institute recommends Roman numbers (I, II, III, IV) to signify Tier-based projects.
Myth: Uptime Institute Tiers is U.S.-centric.
Uptime: The Uptime Institute is currently delivering Tier Certifications in over 25 countries. During the design and construction of these projects, there has not been a conflict between Tiers and local building codes, statutes, or jurisdictions. Tiers, which allows for many solutions and a variety of configurations, gives the engineering and operations team the flexibility to meet both the local regulations and the performance requirements.
Myth: Uptime Institute Tiers requires an EPO.
Uptime: Analysis of the Uptime Institute's Abnormal Incident Report database reveals that accidental EPO activation is a recurring cause of downtime. Uptime Institute Tiers does not mandate an EPO. Unless compelled by a local jurisdiction or code, Uptime Institute does not recommend EPO installation. However, if an EPO is installed, it must also incorporate the Concurrent Maintainability or Fault Tolerant objectives, as specified by the owner.
Myth: Uptime Institute Tiers requires raised floor.
Uptime: The choice of underfloor or overhead cooling is an owner decision based an operational preference. In Uptime Institute experience, a raised floor enhances operational flexibility over the long term. Yet, decisions such as raised floor or on-slab, Cold Aisle/Hot Aisle, containment of Cold/Hot Aisles, and gallery cooling can affect the efficiency of the computer room environment, but are NOT mandated by Uptime Institute Tiers.
Myth: For Tier III and IV, the engine-generator plant must be operational at all times.
Uptime: Data centers will utilize the public electrical utility a majority of the time. However, the engine-generator plant must be properly configured and sized to carry the critical load without runtime limitations. Meeting this criteria requires special attention to the engine-generator capacity ratings and the feeds to the engine-generator plant. In all cases, Uptime Institute Tiers does not require that the engine-generator plant run at all times.
The Uptime Institute has recently released two Accredited Tier Designer Technical Papers. These papers, part of an ongoing series, provide technical clarity on the Tier consequences of specific subsystems. The topics, makeup water source and engine-generator ratings, were identified as areas of concern by attendees from over 13 countries at the 2010 Accredited Tier Designer sessions.
The Accredited Tier Designer Technical Paper Series and Tier Standard: Topology is available at http://uptimeinstitute.com/resources.
If you would like more information on Tier Certification, please click HERE. |