Method for handling interrupted writes using multiple cores

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.

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.