Fault tolerant modular subsystems for computers

A fault tolerant computing facility which includes a housing array for containing a plurality of hardware element modules (24) such as disk drives (26), a plurality of modularized power supplies (32) and plural power distribution modules (40,42), each being connected to a separate source of primary facility power. Each module is self aligning and blind-mateable with the housing and may be installed and removed without tools, without disturbing the electrical cabling within the cabinet, and automatically by a maintenance robot. The logical identity of each module is established by programming at a control panel (16) and by corresponding physical location of installation of each module within the housing array.