Patent ID: 8732699

Claim:
A method for use in a system having plural physical machines, comprising: defining plural groups including corresponding subsets of the plural physical machines, wherein defining the plural groups comprises: storing, by a first controller, state information of the respective subset of the physical machines in a first group of the plural groups; storing, by a second controller, state information of the respective subset of the physical machines in a second group of the plural groups, wherein the state information stored by the first controller is different from the state information stored by the second controller; detecting that a first placement of virtual machines on the physical machines in the first group violates a policy; determining that one or more of the virtual machines have to be migrated outside the first group to satisfy the policy; identifying, by the first controller in the first group, a second placement of virtual machines in which the one or more virtual machines are to be migrated from the first group to the second group; and performing migration of the one or more virtual machines between or among the physical machines in the first and second groups according to the identified second placement.