Open Rack is an Open Compute Project standard for a rack and power delivery architecture as an efficient, scalable alternative to the EIA-310 19-inch rack. It is designed specifically for large-scale cloud deployments.
There are several key design features intended to make equipment more efficient to deploy, support, and operate:
Open Rack rack units, also called OpenU or just OU, measure 48mm in height and describe how tall a rack or piece of equipment is, similar to U when referring to traditional 19-inch racks. For example, a "2OU server" would measure in height.
An Open Rack consists of three modular zones: power, equipment, and cable.
To maintain compatibility with existing server infrastructure, OU cabinets are the same external width as conventional server cabinets. However, an OpenU is slightly taller, to improve airflow and cable management.
An equipment bay is wide. An equipment bay rests on support shelves and blind-mates with the power supply through busbars.