System and method for loosely coupled temporal storage management

• US 7,257,689 B1
• Filed: 10/15/2004
• Issued: 08/14/2007
• Est. Priority Date: 10/15/2004
• Status: Active Grant

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Veritas Operating Corporation (Gen Digital Inc.)
• Inventors: Baird, Robert
• Primary Examiner(s): LANE, JOHN A
• Application Number:
  US10/966,791
• Time in Patent Office: 1,033 Days
• Field of Search: 707/201, 707/204, 711/162
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1466 to make the backup process non-disruptive
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 11/1474 in transactions G06F16/20 takes precedence
• CPC Class Codes: G06F 16/1805 Append-only file systems, e.g. using logs or journals to store data
• CPC Class Codes: Y10S 707/99952 Coherency, e.g. same view to multiple users
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A system for loosely coupled temporal storage management includes a logical storage aggregation including a plurality of data blocks, a data producer, one or more data consumers, and a temporal storage manager. The temporal storage manager may be configured to maintain a producer shadow store including entries stored in a log-structured logical volume, where each entry is indicative of one or more data blocks of the logical storage aggregation that have been modified by the data producer. The temporal storage manager may also be configured to maintain a repository containing a baseline version of the logical storage aggregation, and to provide the data consumers with read-only access to the producer shadow store and the repository.

Claims

1. A system comprising:

a logical storage aggregation comprising a plurality of data blocks;

a data producer;

one or more data consumers; and

a temporal storage manager,

wherein the temporal storage manager is configured to;

maintain a producer shadow store containing a plurality of entries in a log-structured logical volume, wherein each entry of the plurality of entries is indicative of a modification of one or more data blocks of the logical storage aggregation by the data producer;

maintain a repository containing a baseline version of the logical storage aggregation; and

provide the one or more data consumers read-only access to the producer shadow store.

2. The system as recited in claim 1, wherein the temporal storage manager is further configured to merge an entry of the plurality of entries with the repository.

3. The system as recited in claim 2, wherein the temporal storage manager is further configured to remove a merged entry of the plurality of entries from the log-structured logical volume.

4. The system as recited in claim 1, wherein the temporal storage manager is further configured to provide the one or more data consumers and the data producer with read-only access to the repository.

5. The system as recited in claim 1, wherein each entry of the plurality of entries comprises one or more modified data blocks and an index to the one or more modified data blocks.

6. The system as recited in claim 1, wherein each entry of the plurality of entries contains a timestamp indicative of a time of modification of the one or more data blocks.

7. The system as recited in claim 1, wherein, in response to a read request for a specified block of the logical storage aggregation from a data consumer of the one or more data consumers, the temporal storage manager is configured to:

search the producer shadow store for the specified block;

return a shadow copy of the specified block to the data consumer in response to a detection of the specified block in the producer shadow store;

return a repository copy of the specified block to the data consumer from the repository in response to a detection of an absence of the specified block in the producer shadow store.

8. The system as recited in claim 1, wherein the temporal storage manager is further configured to maintain connection information for a data consumer of the one or more data consumers, wherein the connection information is indicative of a version of the logical storage aggregation being accessed by the data consumer.

9. The system as recited in claim 1, wherein the temporal storage manager is further configured to create one or more archived versions of the logical storage aggregation.

10. The system as recited in claim 1, wherein the temporal storage manager is further configured to create one or more snapshots of the logical storage aggregation.

11. The system as recited in claim 1, wherein the temporal storage manager is further configured to create one or more replicas of the logical storage aggregation.

12. The system as recited in claim 1, further comprising a plurality of nodes forming a cluster, wherein the data producer comprises a plurality of data producer instances including a first data producer instance at a first node of the cluster and a second data producer instance at a second node of the cluster;

wherein the temporal storage manager is further configured to;

maintain a first producer shadow store associated with the first data producer instance at the first node;

maintain a second producer shadow store associated with the second data producer instance at the second node; and

exchange coordination messages between the first node and the second node in order to maintain a single consistent image of the logical storage aggregation using a combination of the first and second producer shadow stores.

13. The system as recited in claim 1, wherein, in response to a request for a locally modifiable copy of the logical storage aggregation from a first data consumer of the one or more data consumers, the temporal storage manager is configured to:

initialize a consumer shadow store for the first data consumer, wherein the consumer shadow store is associated with a frozen image of the repository;

and wherein, in response to a request for a local modification of one or more data blocks of the logical storage aggregation from the first data consumer, the temporal storage manager is further configured to;

append a local entry into the consumer shadow store, wherein the local entry is indicative of the local modification by the first data consumer.

14. The system as recited in claim 1, further comprising a plurality of nodes forming a cluster, wherein the temporal storage manager is incorporated at a first node of the cluster, and wherein, in response to a failure, the temporal storage manager is configured to fail over to a second node of the cluster.

15. The system as recited in claim 1, further comprising an intelligent storage device, wherein the intelligent storage device is one of:

an intelligent disk array, a virtualization appliance, and a virtualization switch; and

wherein the repository is stored at the intelligent storage device.

16. A method comprising:

maintaining a producer shadow store containing a plurality of entries in a log-structured logical volume, wherein each entry of the plurality of entries is indicative of a modification of one or more data blocks of a logical storage aggregation by a data producer;

maintaining a repository containing a baseline version of the logical storage aggregation; and

providing one or more data consumers read-only access to the producer shadow store.

17. The method as recited in claim 16, further comprising:

merging an entry of the plurality of entries with the repository.

18. The method as recited in claim 17, further comprising:

removing a merged entry of the plurality of entries from the log-structured logical volume.

19. The method as recited in claim 16, further comprising:

providing the one or more data consumers read-only access to the repository.

20. The method as recited in claim 16, further comprising:

responding to a read request for a specified block of the logical storage aggregation by;

searching the producer shadow store for the specified block;

returning a shadow copy of the specified block in response to a detection of the specified block in the producer shadow store;

returning a repository copy of the specified block from the repository in response to a detection of an absence of the specified block in the producer shadow store.

21. The method as recited in claim 16, further comprising:

maintaining connection information for each of the one or more data consumers, wherein the connection information is indicative of an entry of the logical storage aggregation being accessed by the corresponding data consumer.

22. The method as recited in claim 16, further comprising:

creating one or more archived versions of the logical storage aggregation.

23. The method as recited in claim 16, further comprising:

maintaining a first producer shadow store associated with a first data producer instance at a first node of a cluster;

maintaining a second producer shadow store associated with a second data producer instance at a second node of a cluster; and

exchanging coordination messages between the first node and the second node in order to maintain a single consistent image of the logical storage aggregation using a combination of the first and second producer shadow stores.

24. The method as recited in claim 16, further comprising:

responding to a request for a locally modifiable version of the logical storage aggregation from a first data consumer of the one or more data consumers by initializing a consumer shadow store associated with a frozen image of the repository; and

appending a local entry into the consumer shadow store, wherein the local entry is indicative of a local modification of one or more data blocks of the logical storage aggregation by the first data consumer.

25. A computer-accessible storage medium comprising program instructions, wherein the program instructions are executable to:

maintain a producer shadow store including a plurality of entries stored in a log-structured logical volume, and wherein each entry of the plurality of entries is indicative of a modification of one or more data blocks of a logical storage aggregation by a data producer;

maintain a repository containing a baseline version of the logical storage aggregation; and

provide one or more data consumers read-only access to the producer shadow store.

26. The computer-accessible storage medium as recited in claim 25, further comprising program instructions executable to:

merge an entry of the plurality of entries with the repository.

27. The computer-accessible storage medium as recited in claim 25, further comprising program instructions executable to:

remove a merged entry of the plurality of entries from the log-structured logical volume.

28. The computer-accessible storage medium as recited in claim 25, further comprising program instructions executable to:

provide the one or more data consumers read-only access to the repository.

29. The computer-accessible storage medium as recited in claim 25, further comprising program instructions executable to:

respond to a read request for a specified block of the logical storage aggregation by;

searching the producer shadow store for the specified block;

returning a shadow copy of the specified block in response to a detection of the specified block in the producer shadow store;

returning a repository copy of the specified block from the repository in response to a detection of an absence of the specified block in the producer shadow store.

30. The computer-accessible storage medium as recited in claim 25, further comprising program instructions executable to:

maintain connection information for each of the one or more data consumers, wherein the connection information is indicative of an entry of the logical storage aggregation being accessed by the corresponding data consumer.

31. The computer-accessible storage medium as recited in claim 25, further comprising program instructions executable to:

create one or more archived versions of the logical storage aggregation.

32. The computer-accessible storage medium as recited in claim 25, further comprising program instructions executable to:

maintain a first producer shadow store associated with a first data producer instance at a first node of a cluster;

maintain a second producer shadow store associated with a second data producer instance at a second node of a cluster; and

exchange coordination messages between the first node and the second node in order to maintain a single consistent image of the logical storage aggregation using a combination of the first and second producer shadow stores.

33. The computer-accessible storage medium as recited in claim 25, further comprising program instructions executable to:

respond to a request for a locally modifiable version of the logical storage aggregation from a first data consumer of the one or more data consumers by initializing a consumer shadow store associated with a frozen image of the repository; and

insert a local entry into the consumer shadow store, wherein the local entry is indicative of a local modification of one or more data blocks of the logical storage aggregation by the first data consumer.