N+2 is a redundancy configuration that provides two spare units beyond the base capacity needed to carry the full load (N). It keeps the system fully supported even if one unit is down for maintenance while a second fails concurrently, offering higher resilience than N+1 for critical power and cooling equipment at additional capital and space cost.
Category: Resilience & Availability · Subcategory: Redundancy Topologies · Part of the AIDC Technical Terminology reference.