The challenges of setting up and operating a Petabyte Class Archive will be described in terms of computer systems
within a complex Data Centre environment. The computer systems, including the ESO Primary and Secondary Archive
and the associated computational environments such as relational databases will be explained. This encompasses the
entire system project cycle, including the technical specifications, procurement process, equipment installation and all
further operational phases. The ESO Data Centre construction and the complexity of managing the environment will be
presented. Many factors had to be considered during the construction phase, such as power consumption, targeted
cooling and the accumulated load on the building structure to enable the smooth running of a Petabyte class Archive.