Modular data center

An apparatus, comprising:

• a first modular building, comprising:
• a rack assembly comprising a plurality of racks coupled to one another, wherein:
• respective racks among the plurality of racks are configured to hold a plurality of rack-mounted computing devices arrayed in a first direction;
• the plurality of racks are arrayed in one or more directions orthogonal to the first direction for respective racks, with respective racks positioned side-by-side;
• and
• a rack-assembly enclosure, wherein:
• the first modular building envelopes the rack assembly;
• the first modular building comprises a first room having a door configured to provide a passage by which a technician walks into the first room;
• the rack-assembly enclosure is configured to selectively provide access by the technician in the first room to at least part of the racks;
• the first modular building is a modular housing configured to be transported on a first truck and protect the rack assembly from weather;
• and
• the rack-assembly enclosure comprises a plurality of access barriers mechanically coupled to a given one of the racks, the access barriers being configured to secure and selectively provide access to different respective subsets of rack units in the given one of the racks from access via an opening to a portion of the respective subset of rack units extending through the opening, wherein:
• a first access barrier among the plurality of access barriers is configured to secure and selectively provide access to a first subset of the rack units in the given one of the racks;
• a second access barrier among the plurality of access barriers is configured to secure and selectively provide access to a second subset of the rack units in the given one of the racks;
• and
• the second subset of the rack units is disjoint from the first subset of the rack units;
• and
• a second modular building comprising a cooling unit, the second modular building being coupled to a face the first modular building by a interface and configured to:
• cool the plurality of rack-mounted computing devices by removing heat from a cooling fluid circulated through the rack assembly;
• protect the cooling unit from weather;
• be transported on a second truck to an edge-based data center site;
• and
• couple a face of the second modular building to the face of the first modular building at the edge-based data center site.