What defines a data center with concurrently maintainable infrastructure?

A data center with concurrently maintainable infrastructure is defined by its capability to perform maintenance activities without disrupting the operations of the data center. This means that any component can be taken offline for maintenance while the data center continues to function seamlessly with the remaining components.

In this context, Tier III data centers are designed with a redundant infrastructure that allows for concurrent maintainability. They have multiple paths for power and cooling, ensuring that even if one path is taken offline for maintenance, the other paths can handle the load. This level of reliability is crucial for businesses that cannot afford downtime.

Tiers I and II do not provide this level of infrastructure redundancy. Tier I data centers have a single path for power and cooling; thus, they are susceptible to potential outages during maintenance. Tier II introduces some redundancy but still does not support concurrent maintainability, as it may not have multiple active paths for critical infrastructure components.

Tier IV data centers, while offering the highest level of redundancy and fault tolerance, are not the answer here because the question specifically asks for concurrently maintainable infrastructure, which Tier III meets sufficiently without the additional complexities of Tier IV.