1. A method of performing live migration of a virtual machine that is executing at a source site to a destination site over an optical network, the method comprising: executing an application program on the virtual machine on behalf of a client system, during which execution the client system maintains communication with the virtual machine and the application program; dynamically establishing a lightpath through the optical network between the source site and the destination site; while the virtual machine continues to execute at the source site and the application program continues to execute on the virtual machine, iteratively transferring a copy of the virtual machine over the acquired lightpath from the source site to the destination site until the iterative transfer produces a consistent copy of the virtual machine at the destination site; and redirecting execution of the application program to the consistent copy of the virtual machine produced at the destination site.