Method for identifying the time at which data was written to a data store

• US 20050063374A1
• Filed: 03/12/2004
• Published: 03/24/2005
• Est. Priority Date: 09/23/2003
• Status: Active Grant

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Revivio, Inc. (Gen Digital Inc.)
• Inventors: Rowan, Michael T., Rodgers, Kevin F.
• Granted Patent: US 7,725,667 B2
• Time in Patent Office: Days
• US Class Current: 370/382
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery

Abstract

A method, apparatus, and system for accessing units of storage that depends at least in part on an address of the unit of storage and the time that data was written to the unit of storage. By accessing units of storage in response to a time, prior images of a data store can be generated substantially instantaneously.

Claims

1-25. -25. (Cancelled)

26. A method for identifying a time at which first data was written to a first data store, comprising the steps of:

configuring a second data store to respond to data requests made to the second data store with data stored in the first data store at a first time in the past;

requesting second data from the second data store;

receiving the second data; and

determining from the second data if the first data store contained the first data at the first time.

27. The method of claim 26, further comprising the steps of:

configuring the second data store to respond to data requests made to the second data store with the data stored in the first data store at a second time in the past;

requesting third data from the second data store;

receiving the third data from the second data store; and

determining from the third data if the first data store contained the first data at the second time.

28. The method of claim 26, further comprising the steps of:

configuring the second data store to respond to data requests made to the second data store with the data stored in the first data store at a third time in the past;

requesting fourth data from the second data store;

receiving the fourth data from the second data store; and

determining from the fourth data if the first data store contained the first data at the third time.

29. The method of claim 26 wherein the first data is corrupted data.

30. The method of claim 26 wherein the first data store is the same as the second data store.

31. The method of claim 28 wherein the second time and the third time are selected in response to at least one previously completed determining step.

32. The method of claim 26 wherein the configuring step further comprises communicating the first time to the second data store.

33. The method of claim 32 wherein the configuring step further comprises communicating the first time to the second data store via a channel which is used to communicate the request for second data.

34. The method of claim 32 wherein the configuring step further comprises communicating the first time to the data store via a different channel than a channel used to communicate the request for second data.

35. The method of claim 26 wherein the second data store is a virtual representation of the first data store at the first time.

36. The method of claim 26 wherein the determining step comprises comparing the second data and the first data.

37. The method of claim 26, further comprising, prior to the configuring step, the step of continuously saving information stored in the first data store before it is overwritten.

38. The method of claim 26, wherein the first time is a time selected from a substantially continuous time interval between a past time and a current time.

39. The method of claim 26 wherein the second data store is configured using a user interface.

40. The method of claim 26 wherein the second data store is configured by an I/O command.

41. The method of claim 26 wherein the second data store is configured substantially immediately.

42. The method of claim 41 wherein the second data store is configured substantially immediately relative to at least one time at which first data was written to the first data store.

43. The method of claim 26 wherein the second data store is configured without copying data from the first data store to the second data store.

44. A method for identifying a time at which a data store was corrupted, comprising the steps of:

(a) configuring a data store to respond to data requests made to the data store with data present in the data store at a first time in the past;

(b) requesting data from the data store;

(c) receiving data from the data store in response to the request; and

(d) determining from the received data whether the data store was corrupted at the first time;

(e) repeating steps (a), (b), (c), and (d) by substituting a second time for the first time.

45. The method of claim 44 wherein the second time is earlier than the first time if it was determined that the data store was corrupted, and the second time is later than the first time if it was determined that the data store was not corrupted.

46. The method of claim 45 wherein step (e) comprises repeating steps (a), (b), (c), and (d) a number of repetitions, each repetition substituting a different respective time that was not employed in a previous repetition.

47. The method of claim 45 wherein the second time is earlier than the first time if it was determined that the data store was corrupted, and the second time is later than the first time if it was determined that the data store was not corrupted.

48. The method of claim 46, wherein the repeating step is performed until a time range in which the data store was corrupted is identified.

49. The method of claim 45, further comprising the step of configuring the data store to respond to data requests made to the data store with the data present in the data store during an identified time range.

50. A method for identifying a time at which a data store was modified in a predetermined manner, comprising the steps of:

(a) configuring a data store to respond to data requests made to the data store with data present in the data store at a first time in the past;

(b) requesting data from the data store;

(c) receiving data from the data store in response to the request; and

(d) determining from the received data whether the data store was modified in a predetermined manner at the first time;

(e) repeating steps (a), (b), (c), and (d) by substituting a second time for the first time.

51. The method of claim 50 wherein the second time is earlier than the first time if it was determined that the data store was modified in the predetermined manner, and the second time is later than the first time if it was determined that the data store was not modified in the predetermined manner.

52. The method of claim 51 wherein step (e) comprises repeating steps (a), (b), (c), and (d) a number of repetitions, each repetition substituting a different respective time that was not employed in a previous repetition.

53. The method of claim 51 wherein the second time is earlier than the first time if it was determined that the data store was modified in the predetermined manner, and the second time is later than the first time if it was determined that the data store was not modified in the predetermined manner.

54. The method of claim 52, wherein the repeating step is performed until a time range in which the data store was modified in the predetermined manner is identified.

55. The method of claim 51, further comprising the step of configuring the data store to respond to data requests made to the data store with the data present in the data store during an identified time range.