Architecture for Modular Data Centers
  Several factors are driving high-scale deployments of large data centers built upon commodity components. These commodity clusters are far cheaper than mainframe systems of the past but they bring serious heat and power density issues. Also the high failure rate of the individual components drives significant administrative costs. This proposal outlines an architecture for data center design based upon 20'x8'x8' modules that substantially changes how these systems are acquired, administered, and then later recycled. 
James Hamilton