Architecture for supporting sparse volumes

• US 20070250551A1
• Filed: 04/24/2006
• Published: 10/25/2007
• Est. Priority Date: 04/25/2005
• Status: Active Grant

• Current Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Original Assignee: Network Appliance Incorporated (NetApp, Inc.)
• Inventors: Zheng, Ling, Lango, Jason, Grunwald, David, Ayyar, Kartik, Prakash, Ashish, Ackaouy, Emmanuel, Kesavan, Ram, Eastham, Paul, Quirion, Brian, Wagner, J., Amdur, Matthew, Tsai, Robert, English, Robert
• Granted Patent: US 7,689,609 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/10 File systems; File servers

Abstract

An architecture, including a file-level protocol, for supporting sparse volumes on a storage system is provided. The file-level protocol provides coherency checking for use in retrieving data stored on a backing store remote from a storage system.

Claims

1. A storage system that supports remote retrieval of data, the storage system comprising:

a file system adapted to support data that requires remote retrieval from a backing store, the file system including a function adapted to identify data that is not stored on the storage system and further adapted to retrieve the data using a protocol adapted for re-mote retrieval of data from the backing store;

a protocol module operatively interconnected with the file system and implementing a protocol adapted for remote retrieval of data from the backing store in response to a determination that the data is not stored on the storage system, the protocol module further adapted to return the data to the file system once the data has been retrieved from the backing store

2. The storage system of claim 1 wherein the function comprises a function to load a block of the file system.

3. The storage system of claim 1 wherein the protocol utilizes a transport control protocol/internet protocol for a transport layer.

4. The storage system of claim 1 wherein the protocol comprises a read request.

5. The storage system of claim 4 wherein the read request comprises a file handle field, a file block number field and a number of blocks to be read field.

6. The storage system of claim 1 wherein the protocol comprises an authentication request.

7. The storage system of claim 6 wherein the authentication request comprises an application field, a type field and a data field.

8. The storage system of claim 1 wherein the protocol comprises an authentication response.

9. The storage system of claim 8 wherein the authentication response comprises status field and a data field.

10. The storage system of claim 1 wherein the protocol comprises a request to lock a persistent consistency point image (PCPI).

11. The storage system of claim 10 wherein the request comprises a file system identifier field and a PCPI name field.

12. The storage system of claim 1 wherein the protocol comprises an initialize request.

13. The storage system of claim 12 wherein the initialize request comprises a protocol version field, an application field and a byte order field.

14. The storage system of claim 1 wherein the protocol comprises an initialize response.

15. The storage system of claim 14 wherein the initialize response comprises a file system version field and a byte order field.

16. The storage system of claim 1 wherein the backing store comprises one or more storage systems.

17. The storage system of claim 1 wherein the protocol comprises a set of operations that return attributes of a data container prior to and following the operation.

18. The storage system of claim 17 wherein the set of operations comprises a remove operation.

19. The storage system of claim 17 wherein the set of operations comprises a rename operation.

20. The storage system of claim 17 wherein the set of operations comprises a create operation.

21. A method for remotely retrieving data by a storage system from a backing store using a protocol, the method comprising the steps of:

initializing a connection between the storage system and the backing store;

sending one or more read requests to the backing store;

in response to the one or more read requests, retrieving requested data from the one or more read requests by the backing store; and

sending one or more read responses to the storage system.

22. The method of claim 21 further comprising the step of sending a lock PCPI command to the storage system.

23. The method of claim 21 wherein the step of initializing a connection between the storage system and the backing store further comprising the steps of:

(a) sending an authentication request to the backing store;

(b) sending an authentication response to the storage system by the backing store;

(c) repeating steps (a)-(b) until a connection is authenticated;

(d) sending an initialization request to the backing store; and

(e) sending an initialization response to the storage system.

24. The method of claim 21 wherein the backing store comprises one or more storage systems.

25. A computer readable medium for remotely retrieving data from a backing store using a protocol adapted to remotely retrieve data from a backing store, the computer readable medium including program instructions for performing the steps of:

initializing a connection between the storage system and the backing store;

sending one or more read requests to the backing store;

in response to the one or more read requests, retrieving requested data from the one or more read requests by the backing store; and

sending one or more read responses to the storage system.

26. The computer readable medium of claim 25 wherein the backing store comprises one or more storage systems.

27. The computer readable medium of claim 25 wherein the step of initializing a connection between the storage system and the backing store further comprises the steps of:

(a) sending an authentication request to the backing store;

(b) sending an authentication response to the storage system by the backing store;

(c) repeating steps (a)-(b) until a connection is authenticated;

(d) sending an initialization request to the backing store; and

(e) sending an initialization response to the storage system