1. An infrastructure management system comprising: a first server comprising a first processor, a first memory, and a first set of program instructions stored in the first memory; a target set of hosts and a target set of virtual machines; wherein the first processor, executing the first set of program instructions: determines a new placement of the target set of virtual machines on the target set of hosts; wherein the new placement comprises a set of virtual machine-host pairs from the target set of hosts and the target set of virtual machines.