1. A system comprising: Federated File System (Federated FS), wherein the Federated FS supports both a uniform namespace implemented by multiple servers and enables migration of files and directories from one server to another, the Federated FS comprising one or more network attached storage (NAS) file servers that stores file oriented directory sets that are exclusive to one or more virtual machines (VMs), wherein the file oriented directory sets include files that are to be accessed by the VMs; at least one NAS server providing storage services to a selected one or more VMs and Hypervisor Platforms hosting those VMs; NAS Virtualization Management system (NAS VMS), which interfaces with a Virtualization Management system; wherein the NAS VMS is responsible for dynamically assigning responsibility for supporting file access for the VMs to VM Storage Proxies; and one or ore NAS clients associated with the VMs and enhanced to understand extended semantics for controlling NAS referrals.