Patent ID: 8195627

Claim:
A method, comprising: at a Network Attached Storage (NAS) switch, receiving a policy that includes selective migration rules for determining which moving data objects are to be selectively migrated from one file server storage device to another file server storage device in a storage network based at least in part on file attributes; storing at the NAS switch a records database that contains records representative of data objects stored on a source file server the records comprising file attributes of the data objects but are not the data objects themselves; at the NAS switch, sending to a client a switch file handle associated with one of the data objects, the switch file handle being independent of a location of the data object; mapping at the NAS switch the switch file handle to a NAS file handle, wherein the NAS file handle comprises a location of the data object on the source file server; at the NAS switch, updating the records database to reflect transactions on the source file server, including I/O transactions, associated with the data objects; at the NAS switch, executing the selective migration rules against records in the records database to determine which data objects are to be migrated; selectively migrating, by the NAS switch, the determined data objects from a location on the source file server to a location on a destination file server; and at the NAS switch, updating the NAS file handle of the data objects to include the location of the data objects on the destination file server.