A NAS switch provides file migrations in a NAS storage network that are transparent to the clients. A source 
file server exports an original NAS file handles indicative of object locations on the source 
file server to the NAS switch. The NAS switch modifies the original NAS file handles to an internal 
file system and maps the original NAS file handles to a switch file handles independent of location. The NAS switch exports the switch file handles to a 
client. The 
client looks-up objects and makes NAS requests to the source 
file server using switch file handles. The NAS switch performs 
file migration by first replicating the 
namespace containing data to be migrated from source file 
server to a destination file 
server. Separately, the NAS replicates data which is a relatively longer process than the 
namespace replication. During data replication, 
namespace access requests for objects are directed to the replicated namespace. After data replication, file object requests for migrated objects are redirected to the destination file 
server in a process that is transparent to the 
client.