Servers and hosting
Tier IV datacenter
The highest level in the Uptime Institute's classification: fault-tolerant power and cooling, so any single failure or maintenance leaves the servers running.
The Uptime Institute classifies datacenters in four tiers by how their power and cooling are built. Tier I has a single path and no redundancy; Tier II adds redundant components; Tier III has concurrently maintainable paths, so maintenance needs no downtime; Tier IV is fault-tolerant: two independent, active paths for everything, and a single fault anywhere, or maintenance anywhere, does not interrupt the IT load.
The tier describes the building and its infrastructure, not the servers in it, the network, or the software. A Tier IV site can still host a badly run server, and a well-run server can sit in a Tier II room. What the tier buys is that the building itself is very unlikely to be the reason for an outage.
Certification is done by the Uptime Institute against the design and, for the stricter level, the constructed facility. LuxConnect DC1.1 in Bettembourg, where NovaNode's servers are, is Tier IV certified.