Method and system for version control in a fault tolerant system

• US 20030037282A1
• Filed: 08/15/2001
• Published: 02/20/2003
• Est. Priority Date: 08/15/2001
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Chen, Chin-Te, Chu, Jerry, Berg, Jerry
• Granted Patent: US 6,836,859 B2
• Time in Patent Office: Days
• US Class Current: 714/11
• CPC Class Codes: G06F 11/1433 during software upgrading
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 8/65 Updates security arrangements therefor G06F21/57

Abstract

A method and system for performing software versioning between multiple controllers in a fault tolerant system. The fault tolerant system includes a storage system and multiple redundant controllers that provide access to the storage system. The storage system has stored thereon a preferred version of software to be used by the controllers. This software may be updated. The controllers each contain non-volatile memory. On boot, a controller compares the software version in its non-volatile memory to the preferred version in the storage system. If they are different (e.g., the software on the storage system was updated or the controller was updated with a non-preferred software version), then the controller copies the storage system version into its non-volatile memory and then re-boots. One controller is typically left operational while the other is re-booted for redundancy. Computer controlled versioning allows (1) lockstep software updates between the controllers based on a software version that may be associated with the storage system as a whole and (2) provides a central store from which the controllers may obtain the preferred software version. A special flash update mechanism is also described with respect to an implementation that uses flash memory as the non-volatile memory.

Claims

1. A method of providing version control within a fault tolerant system comprising:

a) invoking a boot sequence of a first controller that is coupled to a nonvolatile storage system;

b) during said boot sequence, comparing a preferred application version with a stored application version stored within a memory of said first controller;

c) provided said stored application version is different from said preferred application version, storing said preferred application version into said memory; and

d) provided said stored application version is the same as said preferred application version, causing said first controller to execute said stored application version.

2. A method as described in claim 1 wherein said preferred application version is stored in said non-volatile storage system and wherein c) comprises causing said first controller to re-boot.

3. A method as described in claim 1 wherein said memory is a programmable non-volatile memory.

4. A method as described in claim 1 wherein said memory is a flash memory.

5. A method as described in claim 1 wherein said non-volatile storage system is a disk array storage system.

6. A method as described in claim 1 wherein said preferred application version provides an interface between a host server and said non-volatile storage system.

7. A method as described in claim 1 wherein said invoking a boot sequence comprises:

a1) executing a first level wake-up boot sequence;

a2) during said first level boot sequence, checking two application versions that are associated with a second level boot sequence and selecting a most recent valid version; and

a3) executing said most recent valid version as said second level boot sequence.

8. A method as described in claim 7 wherein said invoking a boot sequence further comprises:

a4) during said second level boot sequence, checking two application versions that are associated with a third level boot sequence and selecting a most recent valid version; and

a5) executing said most recent valid version as said third level boot sequence.

9. A method as described in claim 8 wherein said second level boot sequence performs hardware discovery and base level diagnostics.

10. A method as described in claim 1 wherein said fault tolerant system further comprises a second controller coupled to said non-volatile storage system and wherein said method further comprises:

invoking a boot sequence of said second controller while said first controller is operational;

during said boot sequence of said second controller, comparing said preferred application version with a stored application version that is stored within a memory of said second controller;

provided said stored application version of said second controller is different from said preferred application version, storing said preferred application version into said memory of said second controller and causing said second controller to re-boot; and

provided said stored application version of said second controller is the same as said preferred application version, causing said second controller to execute said stored application version.

11. A method of providing version control within a fault tolerant system comprising a non-volatile storage system coupled to first and second controllers, said method comprising the steps of:

a) while said second controller is operational, invoking a boot sequence of said first controller wherein said non-volatile storage system contains a preferred application version that is associated with said non-volatile storage system;

b) during said boot sequence, comparing said preferred application version with a stored application version stored within a memory of said first controller;

c) provided said stored application version is different from said preferred application version, storing said preferred application version into said memory; and

d) provided said stored application version is the same as said preferred application version, causing said first controller to execute said stored application version.

12. A method as described in claim 11 wherein c) comprises causing said first controller to re-boot.

13. A method as described in claim 11 wherein said memory is a flash memory.

14. A method as described in claim 11 wherein said preferred application version provides an interface between a host server and said nonvolatile storage system.

15. A method as described in claim 11 wherein said step a) comprises the steps of:

a1) executing a first level wake-up boot sequence;

a2) during said first level boot sequence, checking two application versions that are associated with a second level boot sequence and selecting a most recent valid version; and

a3) executing said most recent valid version as said second level boot sequence.

16. A method as described in claim 15 wherein said step a) further comprises the steps of:

a4) during said second level boot sequence, checking two application versions that are associated with a third level boot sequence and selecting a most recent valid version; and

a5) executing said most recent valid version as said third level boot sequence.

17. A method as described in claim 16 wherein said second level boot sequence performs hardware discovery and base level diagnostics.

18. A method as described in claim 11 wherein said method further comprises the steps of:

invoking a boot sequence of said second controller while said first controller is operational;

during said boot sequence of said second controller, comparing said preferred application version with a stored application version stored within a memory of said second controller;

provided said stored application version of said second controller is different from said preferred application version, storing said preferred application version into said memory of said second controller and causing said second controller to re-boot; and

provided said stored application version of said second controller is the same as said preferred application version, causing said second controller to execute said stored application version.

19. A fault tolerant system comprising:

a non-volatile storage system containing a preferred application version;

a first controller coupled to said non-volatile storage system and comprising a first memory containing an application version; and

a redundant second controller coupled to said non-volatile storage system and comprising a second memory containing an application version, wherein said first controller, when booting, compares said preferred application version with said application version of said first memory;

wherein said first controller, provided said application version of said first memory is different from said preferred application version, stores said preferred application version into said first memory and re-boots; and

wherein said first controller, provided said application version of said first memory, is the same as said preferred application version, executes said application version of said first memory.

20. A fault tolerant system as described in claim 19 wherein:

said second controller, when booting, compares said preferred application version with said application version of said second memory;

wherein said second controller, provided said application version of said second memory is different from said preferred application version, stores said preferred application version into said second memory and re-boots; and

wherein said second controller, provided said application version of said second memory, is the same as said preferred application version, executes said application version of said second memory.

21. A fault tolerant system as described in claim 19 wherein said first and second memories are each programmable non-volatile memory.

22. A fault tolerant system as described in claim 19 wherein said first and second memories are each flash memory.

23. A fault tolerant system as described in claim 19 wherein said preferred application version is associated with said non-volatile storage system.

24. A fault tolerant system as described in claim 19 wherein said non-volatile storage system is a disk array.

25. A method of providing version control within a storage system comprising:

a) invoking a boot sequence of a first controller that is coupled to a storage device having stored thereon a first application version;

b) during said boot sequence, comparing the first application version to a second application version stored in a memory of said first controller; and

c) if the first application version is different from the second application version, reconciling the first controller and the storage device such that the same application version is stored on both the memory of the first controller and the storage device.

26. The method of claim 25 wherein said reconciling comprises storing the first application version into the memory of the first controller.

27. The method of claim 25 wherein said reconciling comprises storing the second application version into the storage device.

28. The method of claim 25 wherein said reconciling comprises:

if the first application version is more recent than the second application, storing the first application version into the memory of the first controller; and

if the second application version is more recent than the first application, storing the second application version into the storage device.

29. The method of claim 25 wherein c) comprises rebooting the first controller.

30. A fault tolerant system providing version control comprising:

a storage system having stored thereon a first application version;

a first controller coupled to said storage system and for invoking a boot sequence during which said first controller compares the first application version to a second application version stored in a memory of said first controller; and

said first controller, if the first application version is different from the second application version, reconciles between the storage device such that the same application version is stored on both the memory of the first controller and the storage device.

31. The system of claim 30 wherein said first controller performs reconciling by storing the first application version into the memory of the first controller.

32. The system of claim 30 wherein said first controller performs reconciling by storing the second application version into the storage system.

33. The system of claim 30 wherein first controller performs reconciling by:

if the first application version is more recent than the second application, storing the first application version into the memory of the first controller; and

if the second application version is more recent than the first application, storing the second application version into the storage device.

34. A method of providing version control within a fault tolerant system comprising:

a) invoking a boot sequence of a first controller coupled to a storage system;

b) during said boot sequence, comparing a preferred application version with a stored application version stored within a memory of said first controller;

c) provided said stored application version is different from said preferred application version, storing said preferred application version into said memory;

d) provided said stored application version is the same as said preferred application version, causing said first controller to execute said stored application version;

e) invoking a boot sequence of a second controller coupled to said storage system while said first controller is operational;

f) during said boot sequence of said second controller, comparing said preferred application version with a stored application version that is stored within a memory of said second controller;

g) provided said stored application version of said second controller is different from said preferred application version, storing said preferred application version into said memory of said second controller.

35. A method as described in claim 34 further comprising:

h) provided said stored application version of said second controller is the same as said preferred application version, causing said second controller to execute said stored application version.

36. A method as described in claim 34 wherein said preferred application version is stored in said storage system.