Synchronization of storage using comparisons of fingerprints of blocks

• US 8,745,003 B1
• Filed: 05/13/2011
• Issued: 06/03/2014
• Est. Priority Date: 05/13/2011
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Patterson, R. Hugo
• Primary Examiner(s): Perveen, Rehana
• Assistant Examiner(s): BUI, THUY T
• Application Number:
  US13/107,769
• Time in Patent Office: 1,117 Days
• Field of Search: 707/639
• US Class Current: 707/639
• CPC Class Codes: G06F 11/1446 Point-in-time backing up or restoration of persistent data
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: G06F 16/00 Information retrieval; Database structures therefor; File system structures therefor
• CPC Class Codes: G06F 16/128 Details of file system snapshots on the file-level, e.g. snapshot creation, administration, deletion use of snapshots for error detection or correction G06F11/14, G06F11/16
• CPC Class Codes: G06F 16/13 File access structures, e.g. distributed indices arrangements of input from, or output to, record carriers G06F3/06
• CPC Class Codes: G06F 16/1748 De-duplication implemented within the file system, e.g. based on file segments de-duplication techniques in storage systems for the management of data blocks G06F3/0641
• CPC Class Codes: G06F 16/1873 Versioning file systems, temporal file systems, e.g. file system supporting different historic versions of files
• CPC Class Codes: G06F 17/00 Digital computing or data processing equipment or methods, specially adapted for specific functions information retrieval, database structures or file system structures therefor G06F16/00
• CPC Class Codes: G06F 2201/83 the solution involving signatures
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0641 De-duplication techniques
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

A system for processing data comprises a deduplicating system, an interface, and a processor. The deduplicating system stores a copy of data stored in a data storage system by storing a set of segments that is able to reconstruct the data stored in the data storage system. The interface receives an indication to revert data stored in the data storage system to a state of data at a snapshot time stored in the deduplicating system. The processor is configured to determine a subset of the data stored in the data storage system that has changed between the data stored in the data storage system and the state of data at the snapshot time stored in the deduplicating system using a first list of fingerprints associated with the data stored on the data storage system and a second list of fingerprints associated with the state of data at the snapshot time stored in the deduplicating system.

Claims

1. A system for processing data, comprising:

a deduplicating system for storing data segments, wherein the deduplicating system stores a copy of data stored in a data storage system by storing a set of segments that is able to reconstruct the data stored in the data storage system;

an interface for receiving an indication to revert data stored in the data storage system to a state of data at a snapshot time stored in the deduplicating system; and

a processor configured to;

create a new snapshot of the current data stored on the data storage system that is to be restored, wherein the new snapshot comprises a first list of fingerprints;

determine a subset of the data stored in the data storage system that has changed between the data stored in the data storage system and the state of data at the snapshot time stored in the deduplicating system by comparing a the first list of fingerprints associated with the current data stored on the data storage system and a second list of fingerprints associated with the state of data at the snapshot time stored in the deduplicating system, wherein determining the subset comprises identifying a set of fingerprints in the first list of fingerprints associated with the state of current data stored on the data storage system that are not in the second list of fingerprints associated with the state of data at the snapshot time stored in the deduplicating system;

revert the data stored in the data storage system to a state of data at the snapshot time using the identified set of fingerprints not in the snapshot in the deduplicating system by deleting data segments associated with the identified set of fingerprints that are not in the snapshot in the deduplicating system;

transfer data associated with the subset from the deduplicating system to the data storage system; and

revert the data stored in the data storage system to a state of data at the snapshot time using the determined subset of data by inserting the transferred data associated with the subset into appropriate locations in the data storage system.

2. The system as in claim 1, wherein the data storage system for storing data comprises a block storage system.

3. The system as in claim 1, wherein the subset of the data comprises a list of blocks.

4. The system as in claim 3, wherein one block in the list of blocks is associated with one or more segments stored in the deduplicating storage system.

5. The system as in claim 1, wherein transferring data comprises transferring data requested by a user.

6. The system as in claim 1, wherein transferring data comprises transferring all data associated with the subset.

7. The system as in claim 1, wherein the snapshot time is one of a plurality of snapshot times.

8. The system as in claim 1, wherein determining the subset comprises identifying a set of fingerprints in the second list of fingerprints associated with the state of data at the snapshot time stored in the deduplicating system, that are not in the first list of fingerprints associated with the current data stored on the data storage system.

9. A method for processing data, comprising:

receiving an indication to revert data stored in a data storage system to a state of data at a snapshot time stored in the deduplicating system, wherein a deduplicating system stores data segments, wherein the deduplicating system stores a copy of data stored in the data storage system by storing a set of segments that is able to reconstruct the data stored in the data storage system;

create a new snapshot of the current data stored on the data storage system that is to be restored, wherein the new snapshot comprises a first list of fingerprints;

determining a subset of the data stored in the data storage system that has changed between the data stored in the data storage system and the state of data at the snapshot time stored in the deduplicating system by comparing the first list of fingerprints associated with the data stored on the data storage system and a second list of fingerprints associated with the state of data at the snapshot time stored in the deduplicating system, wherein determining the subset comprises identifying a set of fingerprints in the first list of fingerprints associated with the state of current data stored on the data storage system that are not in the second list of fingerprints associated with the state of data at the snapshot time stored in the deduplicating system;

reverting the data stored in the data storage system to a state of data at the snapshot time using the identified set of fingerprints not in the snapshot in the deduplicating system by deleting data segments associated with the identified set of fingerprints that are not in the snapshot in the deduplicating system;

transferring data associated with the subset from the deduplicating system to the data storage system; and

reverting the data stored in the data storage system to a state of data at the snapshot time using the determined subset of data by inserting the transferred data associated with the subset into appropriate locations in the data storage system.

10. The method as in claim 9, wherein the data storage system for storing data comprises a block storage system.

11. The method as in claim 9, wherein the subset of the data comprises a list of blocks.

12. The method as in claim 11, wherein one block in the list of blocks is associated with one or more segments stored in the deduplicating storage system.

13. The method as in claim 9, wherein the processor is further configured to transfer data associated with the subset from the deduplicating system to the data storage system.

14. The method as in claim 13, wherein transferring data comprises transferring data requested by a user.

15. The method as in claim 13, wherein transferring data comprises transferring all data associated with the subset.

16. The method as in claim 9, wherein the snapshot time is one of a plurality of snapshot times.

17. A computer program product for processing data, the computer program product being embodied in a non-transitory computer readable medium and comprising computer instructions for:

receiving an indication to revert data stored in a data storage system to a state of data at a snapshot time stored in the deduplicating system, wherein a deduplicating system stores data segments, wherein the deduplicating system stores a copy of data stored in the data storage system by storing a set of segments that is able to reconstruct the data stored in the data storage system;

create a new snapshot of the current data stored on the data storage system that is to be restored, wherein the new snapshot comprises a first list of fingerprints;

determining a subset of the data stored in the data storage system that has changed between the data stored in the data storage system and the state of data at the snapshot time stored in the deduplicating system by comparing the first list of fingerprints associated with the data stored on the data storage system and a second list of fingerprints associated with the state of data at the snapshot time stored in the deduplicating system, wherein determining the subset comprises identifying a set of fingerprints in the first list of fingerprints associated with the state of current data stored on the data storage system that are not in the second list of fingerprints associated with the state of data at the snapshot time stored in the deduplicating system;

reverting the data stored in the data storage system to a state of data at the snapshot time using the identified set of fingerprints not in the snapshot in the deduplicating system by deleting data segments associated with the identified set of fingerprints that are not in the snapshot in the deduplicating system;

transferring data associated with the subset from the deduplicating system to the data storage system; and

reverting the data stored in the data storage system to a state of data at the snapshot time using the determined subset of data by inserting the transferred data associated with the subset into appropriate locations in the data storage system.