1. A method of installing a software patch in a system, comprising: operating a first controller virtual machine on a network server; determining a time to install the software patch; replicating the first controller virtual machine into a replica controller virtual machine in the system, wherein the replica controller virtual machine includes the software patch; enabling the replica controller virtual machine; synchronizing the first controller virtual machine with the replica controller; and operating the replica controller virtual machine without suspending the first controller virtual machine.