STORING LOSSY HASHES OF FILE NAMES AND PARENT HANDLES RATHER THAN FULL NAMES USING A COMPACT TABLE FOR NETWORK-ATTACHED-STORAGE (NAS)

• US 20100281133A1
• Filed: 07/09/2010
• Published: 11/04/2010
• Est. Priority Date: 03/04/2004
• Status: Active Grant

• Current Assignee: Cufer Asset Ltd LLC (Intellectual Ventures LLC)
• Original Assignee: Sanwork Data Mgmt LLC (Intellectual Ventures LLC)
• Inventors: Brendel, Juergen
• Granted Patent: US 8,219,576 B2
• Time in Patent Office: Days
• US Class Current: 709/213
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/1824 implemented using Network-attached Storage [NAS] architecture distributed or networked storage systems G06F3/067; protocols for distributed storage of data in a network H04L67/1097

Abstract

Multiple Network Attached Storage (NAS) appliances are pooled together by a virtual NAS translator, forming one common name space visible to clients. Clients send messages to the virtual NAS translator with a file name and a virtual handle of the parent directory that are concatenated to a full file-path name and compressed by a cryptographic hash function to generate a hashed-name key. The hashed-name key is matched to a storage key in a table. The full file-path name is not stored, reducing the table size. A unique entry number is returned to the client as the virtual file handle that is also stored in another table with one or more native file handles, allowing virtual handles to be translated to native handles that the NAS appliance servers use to retrieve files. File movement among NAS servers alters native file handles but not virtual handles, hiding NAS details from clients.

Claims

1-6. -6. (canceled)

7. An apparatus, comprising:

a network interface configured to receive a file-access request from a client over a network, wherein the file-access request includes a virtual file handle having a unique identifier;

a translator coupled to the network interface, and configured to receive from the network interface the virtual file handle, extract the unique identifier, and determine a native file handle based at least in part on the unique identifier; and

a request forwarder coupled to the translator and the network interface, and configured to generate a translated file-access request to be sent to a storage device storing a file of the file-access request, wherein the translated file-access request includes the native file handle.

8. The apparatus of claim 7, wherein the storage device is a network attached (NAS) appliance server selected from a plurality of NAS appliance servers.

9. The apparatus of claim 7, wherein the translator is configured to determine the native file handler from an entry in a translation table corresponding to the unique identifier.

10. The apparatus of claim 9, wherein the entry in the translation table is selected from one of a plurality of entries in the translation table and wherein each of the plurality of entries in the translation table includes a server name of a server that stores a file and information related to at least one of read-write privileges, creation, or modification of the file.

11. The apparatus of claim 9, wherein the translation table is an open-file translation table that stores entries for currently open files.

12. The apparatus of claim 7, further comprising:

a hash engine coupled to the network interface, and configured to receive from the network interface, a file name and path location included in an initial file-access request from the client, and to generate a hashed-name key based at least in part on the file name and the path location.

13. The apparatus of claim 12, further comprising a reply generator coupled to the network interface, and configured to generate, in response to the initial file-access request, a reply including the virtual file handle to be sent through the network interface to the client.

14. The apparatus of claim 7, wherein the apparatus is configured to move the file to a second storage device by changing entries in the translation table and by sending commands to the storage device and the second storage device to physically move the file to the second storage device.

15. An apparatus, comprising:

a server configured to receive a translated file-access request of a client device via a network and to provide the translated file-access request to a file system of the apparatus, wherein the translated file-access request includes a native file handle determined based on a virtual file handle included in an original file-access request of the client device; and

a controller coupled to the server, and configured to allow access by the file system to a selected file stored on the apparatus.

16. The apparatus of claim 15, further comprising a redundant disk array configured to store the selected file.

17. The apparatus of claim 15, wherein the controller comprises a small-computer system interface (SCSI) controller.

18. The apparatus of claim 15, wherein the apparatus is configured to send the selected file to the client device via the network in a plurality of network packets.

19. The apparatus of claim 15, wherein the server is configured to modify the translated file-access request to include a native file handle that points to another apparatus, when the selected file is moved from the apparatus to the another apparatus,

20. The apparatus of claim 19, wherein the virtual file handle remains the same.