Stored memory recovery system

• US 20070174681A1
• Filed: 08/31/2006
• Published: 07/26/2007
• Est. Priority Date: 10/19/1999
• Status: Active Grant

• Current Assignee: Xylon LLC (Intellectual Ventures LLC)
• Original Assignee: Idocrase Investments LLC (Intellectual Ventures LLC)
• Inventors: Jian, Zhang, Sun, Hanxiang, Vohariwatt, Janet, Shen, Andrew, Murray, Timothy
• Granted Patent: US 7,844,855 B2
• Time in Patent Office: Days
• US Class Current: 714/8
• CPC Class Codes: G06F 11/1435 using file system or storage system metadata
• CPC Class Codes: G06F 11/2087 with a common controller

Abstract

Various embodiments of systems and methods for preserving saved memory states to which a computer system can be restored are disclosed. In certain embodiments, the systems and methods intercept write operations to protected memory locations and redirect them to alternate memory locations. Embodiments of the systems and methods include creation of a table for each memory state. Certain embodiments additionally include a recovery capability, by which the protected memory in the computer system is capable of being restored or recovered to a recovery point that represents a saved memory state. Further embodiments relate to systems and methods for preventing protected memory locations from being overwritten that utilize a plurality of memory state values.

Claims

1. A method of recovery to a saved memory state in a computer system having a memory, the method comprising:

receiving a write request to a first memory location;

determining whether said first memory location contains protected data;

redirecting said write request to a second memory location if said first memory location contains protected data, thereby preserving the contents of the first memory location for a first recovery point; and

redirecting a subsequent write request to said second memory location to a third memory location, thereby preserving the contents of said second memory location for a second recovery point.

2. The method of claim 1, further comprising redirecting a read request to said first memory location to said second memory location, thereby returning the contents of said second memory location in response to said read request to said first memory location.

3. The method of claim 1, further comprising redirecting a read request to said second memory location to said third memory location, thereby returning the contents of said third memory location in response to said read request to said second memory location.

4. The method of claim 1, wherein the memory is accessed via a network.

5. The method of claim 1, wherein the memory is a disk drive and the memory states are sector states of the disk drive.

6. The method of claim 5, wherein the disk drive is accessed via a network.

7. The method of claim 1, wherein said protected data contained in said first memory location is operating system data of the computer system.

8. The method of claim 1, wherein said first recovery point represents a configuration of the computer system.

9. The method of claim 1, wherein said first and second recovery points are configuration states, memory states, recovery states, sector states, or computer states.

10. A method of storing a saved memory state in a computer system having a memory, the method comprising:

selecting a first addressable memory location as part of a first recovery point;

receiving a write request to said first addressable memory location;

redirecting said write request to a second addressable memory location;

selecting said second addressable memory location as part of a second recovery point; and

redirecting a subsequent write request to said second addressable memory location to a third addressable memory location.

11. The method of claim 10, further comprising redirecting a read request to said first addressable memory location to said second addressable memory location, thereby returning the contents of said second addressable memory location in response to said read request to said first addressable memory location.

12. The method of claim 10, further comprising redirecting a read request to said second addressable memory location to said third addressable memory location, thereby returning the contents of said third addressable memory location in response to said read request to said second addressable memory location.

13. The method of claim 10, further comprising creating said second recovery point is in response to a timer event.

14. The method of claim 10, further comprising creating said second recovery point is in response to satisfaction of a pre-determined condition.

15. The method of claim 10, wherein said first recovery point represents a configuration of the computer system.

16. The method of claim 10, wherein said first and second recovery points are configuration states, memory states, recovery states, sector states, or computer states.

17. A method of protecting a memory location from being overwritten, the method comprising:

creating a table of a status of at least one memory location;

receiving a write request to a first memory location;

determining if said first memory location contains protected data from a status of said first memory location in said table;

redirecting said write request to a second memory location if said first memory location contains protected data;

indicating a status of said second memory location in said table that said second memory location contains protected data;

redirecting a write request to said second memory location to a third memory location; and

indicating a status of said third memory location in said table that said third memory location contains protected data.

18. The method of claim 17, further comprising redirecting a read request to said first memory location to said second memory location, thereby returning the contents of said second memory location in response to said read request to said first memory location.

19. The method of claim 17, further comprising redirecting a read request to said second memory location to said third memory location, thereby returning the contents of said third memory location in response to said read request to said second memory location.

20. A method of restoring a computer system to a saved memory state, the method comprising:

designating at least one memory location as recovery data associated with a first recovery point;

redirecting write requests to said at least one memory location to another memory location; and

recovering to said first recovery point by designating said at least one memory location and said another memory location as recovery data associated with a second recovery point.

21. The method of claim 20, wherein the memory locations are accessed via a network.

22. The method of claim 20, wherein the memory locations are locations on a disk drive.

23. The method of claim 22, wherein the disk drive is accessed via a network.

24. The method of claim 20, wherein said recovering to said first recovery point is initiated by an enterprise manager executing on a remote computer system that is connected to the computer system via a network.

25. The method of claim 20, wherein said recovering to said first recovery point is in response to a timer event.

26. The method of claim 20, wherein said recovering to said first recovery point is in response to satisfaction of a pre-determined condition.

27. The method of claim 20, wherein said first recovery point and said second recovery point comprise operating system data of the computer system.

28. The method of claim 20, wherein said first recovery point represents a configuration of the computer system.

29. The method of claim 20, wherein said first and second recovery points are configuration states, memory states, recovery states, sector states, or computer states.

30. The method of claim 20, further comprising:

creating a virtual drive having user data files associated with said second recovery point; and

copying said user data files from said virtual drive to an active operating environment of the computer system.

31. A computer operating system configured to preserve protected memory locations that reside on a computer system and recover to a recovery point that represents a saved state of said protected memory locations, the computer operating system comprising:

a table containing data indicating the status of protected memory locations, wherein said table is initialized to indicate an original state of said protected memory locations; and

a driver configured to;

receive a write request to a first memory location;

determine whether said first memory location is a protected memory location;

if said first memory location is a protected memory location, find a second memory location that has a status of not used;

update said table to indicate a used status of said second memory location;

redirect said write request from said first memory location to said second memory location; and

update said table to indicate a redirected status of said first memory location to said second memory location.

32. The computer operating system of claim 31, wherein the driver is further configured to redirect a read request to said first memory location to said second memory location, thereby returning the contents of said second memory location in response to said read request to said first memory location.

33. The computer operating system of claim 31, wherein the driver is further configured to:

receive a write request to said second memory location;

determine whether said second memory location is a protected memory location;

if said second memory location is a protected memory location, find a third memory location that has a status of unused;

update said table to indicate a used status of said third memory location;

redirect said write request from said second memory location to said third memory location; and

update said table to indicate a redirected status of said second memory location to said third memory location.

34. The computer operating system of claim 33, wherein the driver is further configured to redirect a read request to said second memory location to said third memory location, thereby returning the contents of said third memory location in response to said read request to said second memory location.

35. The computer operating system of claim 33, wherein the memory locations are accessed via a network.

36. The computer operating system of claim 33, wherein the memory locations are locations on a disk drive.

37. The computer operating system of claim 36, wherein the disk drive is accessed via a network.

38. The computer operating system of claim 33, wherein said protected memory locations contain operating system data of the computer system.

39. The computer operating system of claim 31, further comprising a module configured to create a virtual drive having user data files associated with the recovery point.

40. A method of preserving protected memory locations that reside on a computer system and recovering to a recovery point that represents a saved state of said protected memory locations, the method comprising:

initializing a table containing data indicating the status of protected memory locations to indicate an original state of said protected memory locations;

receiving a write request to a first memory location;

determining whether said first memory location is a protected memory location;

if said first memory location is a protected memory location, finding a second memory location that has a status of not used;

updating said table to indicate a used status of said second memory location;

redirecting said write request from said first memory location to said second memory location; and

updating said table to indicate a redirected status of said first memory location to said second memory location.

41. The method of claim 40, further comprising redirecting a read request to said first memory location to said second memory location, thereby returning the contents of said second memory location in response to said read request to said first memory location.

42. The method of claim 40, further comprising:

receiving a write request to said second memory location;

determining whether said second memory location is a protected memory location;

if said second memory location is a protected memory location, finding a third memory location that has a status of unused;

updating said table to indicate a used status of said third memory location;

redirecting said write request from said second memory location to said third memory location; and

updating said table to indicate a redirected status of said second memory location to said third memory location.

43. The method of claim 40, further comprising redirecting a read request to said second memory location to said third memory location, thereby returning the contents of said third memory location in response to said read request to said second memory location.

44. The method of claim 40, wherein the memory locations are accessed via a network.

45. The method of claim 40, wherein said protected memory location contains operating system data of the computer system.

46. A method of creating a plurality of tables in a computer system having protected memory locations, said plurality of tables representing a plurality of recovery points that represent saved states of said protected memory locations, the method comprising:

creating an initial table indicating an original state of protected memory locations, wherein said initial table is associated with an initial recovery point;

identifying a new recovery point representing a new state of said protected memory locations to be preserved;

creating a new table corresponding to said new recovery point, wherein said new table is a copy of said initial table;

comparing said new table to a most recently created previous table; and

if said new table indicates an unused status for a memory location for which a corresponding memory location of said previous table indicates a used status, updating said new table to indicate a status of protected for said memory location.

47. The method of claim 46, wherein the memory locations are accessed via a network.

48. The method of claim 46, wherein the memory locations are locations on a disk drive.

49. The method of claim 48, wherein the disk drive is accessed via a network.

50. The method of claim 46, wherein said identifying the new recovery point is initiated by an enterprise manager executing on a remote computer system that is connected to the computer system via a network.

51. The method of claim 46, wherein said identifying the new recovery point is in response to a timer event.

52. The method of claim 46, wherein said identifying the new recovery point is in response to satisfaction of a pre-determined condition.

53. The method of claim 46, wherein said protected memory locations contain operating system data of the computer system.

54. The method of claim 46, wherein said recovery points represent a configuration of the computer system.

55. The method of claim 46, wherein said recovery points are configuration states, memory states, recovery states, sector states, or computer states.

56. The method of claim 46, further comprising removing said initial recovery point, wherein said removing comprises deleting the table associated with said initial recovery point.

57. The method of claim 56, wherein said removing further comprises releasing memory locations of the deleted table and memory locations no longer needed after removal of said initial recovery point, and wherein the released memory locations are available for use by the computer system.

58. The method of claim 46, further comprising removing said new recovery point, wherein said removing comprises deleting the table corresponding to said new recovery point.

60. The computer readable storage medium of claim 56, the method further comprising redirecting a read request to said first memory location to said second memory location, thereby returning the contents of said second memory location in response to said read request to said first memory location.

61. The method of claim 56, wherein said protected data contained in said first memory location comprises operating system data of the computer system.

59. A computer readable storage medium having stored thereon instructions that when executed by a computer processor perform a method of recovery to a saved memory state in a computer system having a memory, the method comprising:

receiving a write request to a first memory location;

determining whether said first memory location contains protected data;

redirecting said write request to a second memory location if said first memory location contains protected data, thereby preserving the contents of the first memory location for a first recovery; and

redirecting a subsequent write request to said second memory location to a third memory location, thereby preserving the contents of said second memory location for a second recovery.