METHOD FOR HANDLING INTERRUPTED WRITES USING MULTIPLE CORES

• US 20100180151A1
• Filed: 01/15/2009
• Published: 07/15/2010
• Est. Priority Date: 01/15/2009
• Status: Abandoned Application

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Kannan, Senthil, Jibbe, Mahmoud K., Rasappan, Selvaraj
• Application Number:
  US12/354,126
• Publication Number:
  US 20100180151A1
• Time in Patent Office: Days
• US Class Current: 714/5
• CPC Class Codes: G06F 11/1032 Simple parity
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/2092 Techniques of failing over between control units
• CPC Class Codes: G11B 20/1833 by adding special lists or symbols to the coded information G11B20/1806, G11B20/1866 take precedence
• CPC Class Codes: G11B 2220/415 Redundant array of inexpensive disks [RAID] systems

Abstract

An apparatus comprising a storage array, a primary controller, a secondary controller and a solid state device. The storage array may be configured to be accessed by a plurality of controllers. A first of the plurality of the controllers may be configured as the primary controller configured to read and write to and from the storage array during a normal condition. A second of the plurality of the controllers may be configured as the secondary controller configured to read and write to and from the storage array during a fault condition. The solid state device may be configured to (i) store data and (ii) be accessed by the storage array and the secondary controller.

Claims

1. An apparatus comprising:

a storage array configured to be accessed by a plurality of controllers;

a first of said plurality of said controllers configured as a primary controller configured to read and write to and from said storage array during a normal condition;

a second of said plurality of said controllers configured as a secondary controller configured to read and write to and from said storage array during a fault condition; and

a solid state device configured to (i) store data and (ii) be accessed by said storage array and said secondary controller.

2. The apparatus according to claim 1, wherein said storage array accesses said solid state device when (i) said primary controller experiences said fault condition and (ii) said storage array experiences a failure during a write.

3. The apparatus according to claim 1, wherein said said primary controller reboots during said fault condition.

4. The apparatus according to claim 3, wherein said storage array transfers to said secondary controller in response to said fault condition.

5. The apparatus according to claim 4, wherein said transfer is forced.

6. The apparatus according to claim 1, wherein said secondary controller is in a passive state for redundancy during said normal condition.

7. The apparatus according to claim 1, wherein said storage array comprises a plurality of physical drives.

8. The apparatus according to claim 1, wherein said fault condition comprises a NVSRAM interrupted write mode.

9. The apparatus according to claim 1, wherein said data comprises a stripe set.

10. The apparatus according to claim 9, wherein said solid state device stores said data before said data is written to said storage array.

11. The apparatus according to claim 1, wherein said data is stored by said storage device for each write IO request.

12. An apparatus comprising:

means for storing information configured to be accessed by a plurality of controllers;

means for implementing a first of said plurality of said controllers as a primary controller for reading and writing to and from said means for storing during a normal condition;

means for implementing a second of said plurality of said controllers as a secondary controller for reading and writing to and from said means for storing during a fault condition; and

means for implementing a solid state device for (i) storing data and (ii) accessing by a storage array and said secondary controller.

13. A method for preventing data corruption during a double fault condition, comprising the steps of:

(A) creating a LUN to address a storage array comprising a plurality of storage devices;

(B) sending an input/output request to said LUN;

(C) storing a data set of said write input/output to a storage device separate from said plurality of storage devices; and

(D) reading said data set from said separate storage device to generate a parity after a double fault condition.

14. The method according to claim 13, wherein step (B) further comprises the step of:

generating said input/output request by a first controller.

15. The method according to claim 14, wherein said double fault condition causes said first controller to reboot and allow a second controller to control said storage array.

16. The method according to claim 13, wherein said double fault condition occurs in response to one of said storage devices failing.

17. The method according to claim 13, wherein said plurality of storage devices each comprise a disk drive.

18. The method according to claim 13, wherein said double fault condition comprises a failure of (i) said first controller and (ii) one of said storage devices.