Method and apparatus to replicate stateful virtual machines between clouds

and
US Patent 9,256,463
, (Granted)
Abstract. A method including replicating a first virtual machine (VM) in a first cloud and putting the replicated VM in a second cloud. Activating the first VM and pausing the replicated VM. First processing, at the first VM, traffic from VMs in the first cloud, wherein the first processing occurs when the first VM is activated and the replicated VM is paused. Buffering, at a hypervisor of the replicated VM, traffic from VMs in the second cloud, wherein the buffering occurs when the first VM is activated and the replicated VM is paused. Activating the replicated VM in response to state information of the first VM and pausing the first VM. Second processing, at the replicated VM, the buffered traffic according to the state information of the first VM, wherein the second processing occurs when the replicated VM is activated and the first VM is paused.