TRANSPARENT FILE MIGRATION USING NAMESPACE REPLICATION

• US 20080114854A1
• Filed: 01/24/2008
• Published: 05/15/2008
• Est. Priority Date: 04/24/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: NeoPath Networks, Inc. (Cisco Systems, Inc.)
• Inventors: TSIRIGOTIS, Panagiotis, CHAWLA, Rajeev, IYENGAR, Anand, WONG, Thomas
• Granted Patent: US 8,180,843 B2
• Time in Patent Office: Days
• US Class Current: 709/214
• CPC Class Codes: G06F 16/119 Details of migration of file systems migration mechanisms in storage systems G06F3/0647
• CPC Class Codes: G06F 16/184 implemented as replicated file system
• CPC Class Codes: H04L 67/06 specially adapted for file transfer, e.g. file transfer protocol [FTP]
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

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.

Claims

1. A method for accessing an object in a storage network, comprising:

receiving a NAS (Network Attached Storage) file handle including a location of the object on a source file server;

sending as representative of the object, a switch file handle that is independent of the location of the object;

migrating the object from the location on the source file server to a location on a destination file server;

receiving an access request associated with the switch file handle; and

sending the access request to the location on the destination file server.

2-45. -45. (canceled)