1. A method for creating a network farm from a tree topology network, comprising: receiving a logical specification of said farm, said logical specification specifying at least one of device types required by said farm and a number of devices for each of said device types; receiving a communication model for said farm, said communication model specifying expected bandwidth usage for devices of said farm; and ascertaining, responsive to said logical specification and said communication model, a solution set of devices among devices of said tree topology network for constructing said farm, said ascertaining including performing partitioned greedy recursion on switching elements of said tree topology network, said partitioned greedy recursion includes recursively ascertaining, starting from the top level of said tree topology network and recursing toward the lowest switching element level of said tree topology network, the lowest cost solution at each switching element level of said tree topology network, wherein the lowest cost solution that completely satisfies resource requirements of said farm and that is found after said tree topology network is traversed by said partitioned greedy recursion is deemed said solution set of devices.