Method and system for a storage area network

• US 9,213,612 B2
• Filed: 09/29/2009
• Issued: 12/15/2015
• Est. Priority Date: 09/29/2008
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Candelaria, James
• Primary Examiner(s): Rutz, Jared
• Assistant Examiner(s): LILLIS, BRENDAN S
• Application Number:
  US13/121,605
• Publication Number:
  US 20110289261A1
• Time in Patent Office: 2,268 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 11/20 using active fault-masking, e.g. by switching out faulty elements or by switching in spare elements
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 2201/85 Active fault masking without idle spares active fault masking without idle spare hardware where processing functionality is redundant G06F11/2035
• CPC Class Codes: G06F 2212/214 Solid state disk
• CPC Class Codes: G06F 2212/263 Network storage, e.g. SAN or NAS
• CPC Class Codes: G06F 2212/314 In storage network, e.g. network attached cache
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

In a system and method for a storage area network (SAN), a first controller receives a write request for a SAN and communicates with a first nested storage array module (NSAM), the first NSAM manages storage of data onto a shelf and presents the shelf as a logical unit, a buffer stores a portion of a write request from the first controller and aggregates data from the write request for the shelf, from a shelf with a second NSAM, the second NSAM provides a portion of data from the buffer to a third NSAM, the third NSAM manages storage of the portion of data from the buffer to a physical storage unit, and a second controller coupled to the first controller handles requests for the SAN in response to a failure of the first controller.

Claims

1. A system for a storage area network, comprising:

a first controller operable to receive a write request for the storage area network, the first controller in communication with a first nested storage array module, the first nested storage array module operable to manage storage of data using a configuration that supports striping of data across a plurality of shelves, each shelf of the plurality of shelves comprising one or more storage arrays, each storage array of the one or more storage arrays comprising a plurality of physical storage units, the first nested storage array module operable to present the plurality of shelves as a logical unit and wherein the configuration that supports striping of data across the plurality of shelves includes providing parity information for at least one stripe of data to at least one of the plurality of shelves;

a buffer operable to store a portion of a write request from the first controller, the buffer aggregating data from one or more write requests from the first controller for a shelf from the plurality of shelves and reordering of one or more partly invalidated blocks of data from the one or more write requests from the first controller by combining valid portions of the partly invalidated blocks and rewriting one or more valid blocks of data;

the shelf from the plurality of shelves comprising a second nested storage array module, the second nested storage array module comprising one or more third nested storage array modules and operable to provide a portion of data from the buffer to the one or more third nested storage array modules, the one or more third nested storage array modules operable to manage storage of the portion of data from the buffer to a plurality of physical storage units for a storage array of the shelf; and

a second controller coupled to the first controller and operable to monitor health of the first controller and to handle any write requests for the storage area network in response to a failure of the first controller.

2. The system of claim 1, wherein the buffer is a first buffer and further comprising:

a second buffer coupled to the one or more third nested storage array modules, wherein the second buffer stores a write request for the plurality of physical storage units for the one or more storage arrays of the shelf.

3. The system of claim 1, wherein the second controller is in communication with a fourth nested storage array module, the fourth nested storage array module operable to manage storage of data onto a plurality of shelves, and the fourth nested storage array module operable to present the plurality of shelves as a logical unit.

4. The system of claim 1, wherein the first nested storage array module comprises an instance of RAID5.

5. The system of claim 1, wherein the second nested storage array module comprises an instance of RAIDO.

6. The system of claim 1, wherein the third nested storage array module comprises an instance of RAID5.

7. The system of claim 1, wherein the first nested storage array module supports redundant storage.

8. The system of claim 1, wherein the first nested storage array module comprises an instance of at least one of RAIDO, RAID1, RAID3, RAID4, RAID5, RAID6.

9. The system of claim 1, wherein the second storage array module comprises an instance of at least one of RAIDO, RAID1, RAID3, RAID4, RAID5, RAID6, and a configuration that supports striping of data.

10. The system of claim 1, wherein the third storage array module comprises an instance of at least one of RAIDO, RAID1, RAID3, RAID4, RAID5, RAID6, and a configuration that supports striping of data.

11. The system of claim 1, wherein the third nested storage array module supports redundant storage.

12. The system of claim 1, further comprising:

exposing storage on the plurality of shelves to the first controller using Advanced Technology Attachment over Ethernet.

13. The system of claim 1, wherein the plurality of physical storage units are flash drives.

14. The system of claim 1, wherein the buffer comprises software or hardware.

15. The system of claim 14, wherein the hardware is a field programmable gate array (FPGA).

16. The system of claim 1, wherein the at least one shelf that is to receive parity information for each stripe is rotated among the plurality of shelves for each of the plurality of stripes.

17. The system of claim 2, wherein the second buffer comprises hardware.

18. The system of claim 2, wherein the second buffer includes a backup battery.

32. The system of claim 1, wherein the first nested storage array module comprises an instance of RAID5, the second nested storage array module comprises an instance of RAIDO, and the third nested storage array module comprises an instance of RAID5.

33. The system of claim 1, wherein the first nested storage array module comprises an instance of at least one of RAIDO, RAID1, RAID3, RAID4, RAID5, RAID6, the second nested storage array module comprises an instance of at least one of RAIDO, RAID1, RAID3, RAID4, RAID5, RAID6, and the third nested storage array module comprises an instance of at least one of RAIDO, RAID1, RAID3, RAID4, RAID5, RAID6.

19. A method for a storage area network, comprising:

receiving a write request at a first controller, the first controller in communication with a first nested storage array module, the first nested storage array module operable to manage storage of data using a configuration that supports striping of data across a plurality of shelves, each shelf of the plurality of shelves comprising one or more storage arrays, each storage array of the one or more storage arrays comprising a plurality of physical storage units, the first nested storage array module operable to present the plurality of shelves as a logical unit and wherein the configuration that supports striping of data across the plurality of shelves includes providing parity information for at least one stripe of data to at least one of the plurality of shelves;

storing a portion of data corresponding to a write request from the first controller in a buffer;

reordering one or more partly invalidated blocks of data from one or more write requests from the first controller by combining valid portions of the partly invalidated blocks of data and rewriting one or more valid blocks of data; and

sending a portion of data in the buffer to a shelf from the plurality of shelves, the shelf comprising a second nested storage array module, the second nested storage array module comprising one or more third nested storage array modules and operable to provide the portion of data from the buffer to one or more third nested storage array modules, the one or more third nested storage array modules operable to manage storage of the portion of data from the buffer to a plurality of physical storage units for a storage array of the shelf.

20. The method of claim 19, wherein the buffer is a first buffer and further comprising:

buffering some of the portion of data from the first buffer in a second buffer.

21. The method of claim 19, further comprising receiving a write request at a second controller, the second controller in communication with a fourth nested storage array module, the fourth nested storage array module operable to manage storage of data onto a plurality of shelves, and the fourth nested storage array module operable to present the plurality of shelves as a logical unit.

22. The method of claim 19, wherein the first nested storage array module comprises an instance of at least one of RAIDO, RAID1, RAID3, RAID4, RAID5, and RAID6.

23. The method of claim 19, wherein the second storage array module comprises an instance of at least one of RAIDO, RAID1, RAID3, RAID4, RAID5, RAID6, and a configuration that supports striping of data.

24. The method of claim 19, wherein the third storage array module comprises an instance of at least one of RAIDO, RAID1, RAID3, RAID4, RAID5, RAID6, and a configuration that supports striping of data.

25. The method of claim 19, wherein the third nested storage array module supports redundant storage.

26. The method of claim 19, further comprising:

exposing storage on the plurality of shelves to the first controller using Advanced Technology Attachment over Ethernet.

27. The method of claim 19, wherein the plurality of physical storage units are flash drives.

28. The method of claim 19, wherein the buffer comprises software or hardware.

29. The method of claim 28, wherein the hardware is a field programmable gate array (FPGA).

30. The method of claim 20, wherein the second buffer comprises hardware.

31. The method of claim 20, wherein the second buffer includes a backup battery.

34. One or more non-transitory computer readable media comprising instructions for execution that when executed by a processor are operable to perform operations for a storage area network, the operations comprising:

receiving a write request at a first controller, the first controller in communication with a first nested storage array module, the first nested storage array module operable to manage storage of data using a configuration that supports striping of data across a plurality of shelves, each shelf of the plurality of shelves comprising one or more storage arrays, each storage array of the one or more storage arrays comprising a plurality of physical storage units, the first nested storage array module operable to present the plurality of shelves as a logical unit and wherein the configuration that supports striping of data across the plurality of shelves includes providing parity information for at least one stripe of data to at least one of the plurality of shelves;

storing a portion of data corresponding to a write request from the first controller in a buffer;

reordering one or more partly invalidated blocks of data from one or more write requests from the first controller by combining valid portions of the partly invalidated blocks of data and rewriting one or more valid blocks of data; and

sending a portion of data in the buffer to a shelf from the plurality of shelves, the shelf comprising a second nested storage array module, the second nested storage array module comprising one or more third nested storage array modules and operable to provide the portion of data from the buffer to one or more third nested storage array modules, the one or more third nested storage array modules operable to manage storage of the portion of data from the buffer to a plurality of physical storage units for a storage array of the shelf.