Data center tiers
termnetworkinggovernance & risk
Stands for: Uptime Institute data center tiers (I-IV)
The Uptime Institute's I-to-IV classification of data-center resilience - from basic capacity to fault tolerance.
Tier I is basic capacity; Tier II adds redundant components; Tier III is concurrently maintainable (any component can be serviced without shutting production down, the common enterprise/colo target); Tier IV is fault-tolerant, riding through equipment failures. The tiers describe facility topology - power and cooling paths - not operations quality. Distinct from the identically-worded ISP transit tiers and support tiers; three unrelated ladders sharing one word.
Also known as: tier iv, tier iii, uptime institute, data center tier