1. A computer readable medium having stored thereon a data structure operable as a directory service, the data structure comprising: a first data field comprising a service level object map representing a data center and comprising data defining roles for the service level object map and policies for the service level object map, wherein the roles comprise object access control rights, user access control rights, or default access control rights, and wherein policies comprise configuration parameters or actions to be performed; a second data field comprising a rack-level rack object map and in relationship with the service level object map, representing a rack and supporting the directory service, and comprising data defining roles for the rack object map, and policies for the rack object map, wherein the policies for the rack object map are created to group a plurality of managed rack elements through dynamic bindings of entities, and wherein the rack object map is extendable into an auxiliary class to define overwrite policies for the rack object map; and a third data field comprising a managed element object map in relationship with each rack object map, representing server, storage device, or switch, supporting the service, and comprising data defining roles for the managed element object map, and policies for the managed element object map.