Method and system for responding to file system requests

• US 20080133772A1
• Filed: 01/08/2008
• Published: 06/05/2008
• Est. Priority Date: 12/07/2000
• Status: Active Grant

• Current Assignee: NetApp, Inc.
• Original Assignee: Spinnaker Networks, LLC
• Inventors: Sanzi, Richard N., Bianchini, Ronald P., Kazar, Michael L., Gohh, Fred, Nydick, Daniel S., Speiser, Benjamin
• Granted Patent: US 7,917,693 B2
• Time in Patent Office: Days
• US Class Current: 709/238
• 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 16/148 File search processing
• CPC Class Codes: G06F 16/16 File or folder operations, e.g. details of user interfaces specifically adapted to file systems
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• 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]

Abstract

A system for responding to file system requests having file IDs comprising V, a volume identifier specifying the file system being accessed, and R, an integer, specifying the file within the file system being accessed. The system includes D disk elements in which files are stored, where D is greater than or equal to 1 and is an integer. The system includes a switching fabric connected to the D disk elements to route requests to a corresponding disk element. The system includes N network elements connected to the switching fabric. Each network element has a mapping function that for every value of V, specifies one or more elements from the set D that store the data specified by volume V, where N is greater than or equal to 1 and is an integer and N+D is greater than or equal to 3, which receives the requests and causes the switching fabric to route the requests by their file ID according to the mapping function. A method for responding to file system requests. The method includes the steps of receiving file system requests having file IDs comprising V, a volume identifier specifying the file system being accessed, and R, an integer, specifying the file within the file system being accessed at network elements. Each network element has a mapping function that for every value of V, specifies one or more elements from the set D that store the data specified by volume V. Then there is the step of routing the requests to a switching fabric connected to the network elements based on the file system request'"'"'s ID according to the mapping function to disk elements connected to the switching fabric.

Claims

1. A system for responding to file system requests comprising:

a plurality of network elements which receives the requests;

at least one switching element in communication with the network elements which route the requests; and

a plurality of disk elements in which files are stored and which respond to the requests in communication with the switching element.

2. A system as described in claim 2 including a plurality of switching elements in communication with the network elements and the disk elements which route the requests.

3. A system as described in claim 2 wherein each network element insures each request from the network element is only executed once.

4. A system as described in claim 3 wherein the network element retransmits the request for which the network element does not receive an acknowledgment from the switching elements.

5. A system as described in claim 4 wherein the network element authenticates the request.

6. A system as described in claim 5 wherein the network element parses the request.

7. A system as described in claim 6 wherein the network element parses the request into a sequence of file-level file system requests.

8. A system as described in claim 7 wherein the network element translates each request into a back plane file system protocol.

9. A system as described in claim 8 wherein the network elements, switching elements and disk elements are disposed in a server.

10. A system as described in claim 9 wherein the network element determines which disk element stores the file associated with each file request.

11. A system as described in claim 10 wherein the network element sends each request to the disk element having the associated file.

12. A system as described in claim 11 wherein the disk elements include directories whose contents implement a data structure that maps a file name within a directory into a file ID.

13. A system as described in claim 12 including a file system location data base.

14. A system as described in claim 13 wherein the network element interprets requests in POP, SMTP or IMAP protocols in terms of SpinFS operations.

15. A system as described in claim 14 wherein the network element issues look up requests for associated files in the disk elements.

16. A system as described in claim 15 wherein the network element issues read requests for associated files in the disk elements.

17. A system as described in claim 16 wherein the network element issues write requests to write the data into associated files.

18. A system as described in claim 17 wherein the network element issues create file requests to create a file in the disk elements.

19. A system as described in claim 18 wherein the network element issues create directory requests for associated files in the disk elements.

20. A system as described in claim 19 wherein the network element issues a remove a file request for an associated file in the disk elements.

21. A system as described in claim 20 wherein the network element issues a rename a file request for an associated file in the disk elements.

22. A system as described in claim 21 wherein the network element issues a request to lock a file from reading or writing with respect to the file.

23. A system as described in claim 22 wherein the disk elements form a cluster, with one of the disk elements being a cluster coordinator which communicates with each disk element in the cluster to collect from and distribute to the network elements which file systems are stored in each disk element of the cluster.

24. A system as described in claim 23 wherein the cluster coordinator determines if each disk element is operating properly and redistributes requests for any disk element that is not operating properly;

and allocates virtual network interfaces to network elements and assigns responsibility for the virtual network interfaces to network elements for a failed network element.

25. A system as described in claim 24 wherein each network element advertises the virtual interfaces it supports to all disk elements.

26. A system as described in claim 25 wherein each request has an active disk element and a passive disk element associated with each request, wherein if the active disk element fails, the passive disk element is used to respond to the request.

27. A method for responding to file system requests comprising the steps of:

receiving each request at a network element of a plurality of network elements;

routing each request with at least one switching element in communication with the network elements; and

responding to each request with at least one disk element of a plurality of disk elements in which files are stored in communication with the switching element.

28. A method as described in claim 27 including the step of routing requests with a plurality of switching elements in communication with the network elements and the disk.

29. A method as described in claim 28 including the step of executing only once each request from the network element.

30. A method as described in claim 29 including the step of retransmitting by the network element each request for which the network element does not receive an acknowledgment from the switching elements.

31. A method as described in claim 30 including the step of authenticating each request with the network element.

32. A method as described in claim 31 including the step of parsing each request with the network element.

33. A method as described in claim 32 including the step of parsing each request into a sequence of file-level file method requests with the network element.

34. A method as described in claim 33 including the step of translating each request into a back plane file method protocol with the network element.

35. A method as described in claim 34 including the step of determining with the network element which disk element stores the file associated with each request.

36. A method as described in claim 35 including the step of sending each request with the network element to the disk element having the associated file.

37. A method as described in claim 36 wherein the disk elements include directories, and including the step of implementing a data structure that maps a file name within a directory into a file ID.

38. A method as described in claim 37 including the step of interpreting with the network element requests in POP, SMTP or IMAP protocols in terms of SpinFS operations.

39. A method as described in claim 38 including the step of issuing with the network element look up requests for associated files in the disk elements.

40. A method as described in claim 39 including the step of issuing with the network element read requests for associated files in the disk elements.

41. A method as described in claim 40 including the step of issuing with the network element write requests to write the data into associated files.

42. A method as described in claim 41 including the step of issuing with the network element create file requests to create a file in the disk elements.

43. A method as described in claim 42 including the step of issuing with the network element create directory requests for associated files in the disk elements.

44. A method as described in claim 43 including the step of issuing with the network element a remove a file request for an associated file in the disk elements.

45. A method as described in claim 44 including the step of issuing with the network element a rename a file request for an associated file in the disk elements.

46. A method as described in claim 45 including the step of issuing with the network element a request to lock a file from reading or writing with respect to the file.

47. A method as described in claim 46 including the step of forming a cluster with the disk elements, with one of the disk elements being a cluster coordinator which communicates with each disk element in the cluster to collect from and distribute to the network elements which file methods are stored in each disk element of the cluster.

48. A method as described in claim 47 including the steps of determining with the cluster coordinator if each disk element is operating properly and redistributing requests for any disk element that is not operating properly;

and allocating virtual network interfaces to network elements and assigning responsibility for the virtual network interfaces to network elements for a failed network element.

49. A method as described in claim 48 including the step of advertising, by each network element the virtual interfaces it supports to all disk elements.

50. A method as described in claim 49 wherein each request has an active disk element and a passive disk element associated with each request, and including the step of responding with the passive disk element to the request if the active disk element fails.