Systems and methods for resynchronizing information

• US 8,655,850 B2
• Filed: 12/15/2006
• Issued: 02/18/2014
• Est. Priority Date: 12/19/2005
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Ngo, David, Agrawal, Vijay
• Primary Examiner(s): To, Baoquoc N
• Application Number:
  US11/640,024
• Publication Number:
  US 20070198602A1
• Time in Patent Office: 2,622 Days
• Field of Search: 707/202, 707/204, 707/655, 707/656
• US Class Current: 707/672
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 16/1787 Details of non-transparently synchronising file systems
• CPC Class Codes: G06F 16/217 Database tuning G06F16/2282 takes precedence; database performance monitoring G06F11/3409
• CPC Class Codes: G06F 16/27 Replication, distribution or synchronisation of data between databases or within a distributed database system; Distributed database system architectures therefor
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 9/50 Allocation of resources, e.g. of the central processing unit [CPU]
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

Methods and systems for synchronizing data files in a storage network between a first and a second storage device is provided. The method includes storing first data files associated with the first storage device to a storage medium, whereby the first data files include first data records. The storage medium may then be transferred to the second storage device. The first data files from the storage medium may be loaded onto the second storage device. The second data records from the first storage device may be received, and the first and second data records are compared. The first data files at the second storage device may be updated based on the comparison of the first and second data records.

Claims

1. A method of synchronizing data between a first and second storage device comprising:

identifying a first set of changes to first data stored on at least a first storage device for replication;

capturing the first set of changes to the first data in a first log;

transmitting over a network, at least a portion of first set of changes captured in the first log to a second log stored on one or more second storage devices, wherein transmitting the portion of the first set of changes creates a second set of changes in the second log;

replicating at least a portion of the first set of changes to the first data, by performing the second set of changes in the second log to create second data stored on the one or more second storage devices, wherein the second data is a replication of the first data stored on the first storage device;

after detection of a network communication error, comparing the second set of changes in the second log with the first set of changes to the first data to determine whether there is missing change data in the second set of changes; and

updating the second data on the one or more second storage devices upon detection of the missing change data, wherein updating the second data comprises copying at least a portion of updated first data stored on the first storage device to the one or more second storage devices.

2. The method of claim 1 wherein the transmitting the first and second set of data is done periodically.

3. The method of claim 1 wherein the transmitting is executed upon reaching a threshold capacity of the first log.

4. The method of claim 1 further comprising assigning an identifier to a change journal entry.

5. The method of claim 4 further comprising comparing the identifier of the change journal entry to an identifier of a previously stored change journal entry on the second storage device, wherein non-identical identifiers signify non-synchronized data.

6. The method of claim 4 wherein the identifier includes an update sequence number.

7. The method of claim 6 wherein a highest update sequence number indicates the most recent change data.

8. The method of claim 4 wherein the identifier includes a file reference number.

9. The method of claim 1 wherein the second set of data is metadata.

10. The method of claim 1 further comprising storing the second set of data in a second log, the second log linked to the second storage device.

11. A method of synchronizing data after an interruption of data transfer between a first and a second storage device, the method comprising:

transmitting over a network from at least a first storage device, at least a portion of a first set of changes to first data files stored on a first storage device to one or more second storage devices, wherein transmitting the portion of the first set of changes creates a second set of changes on the one or more second storage devices;

performing the second set of changes to create second data files stored in one or more second storage devices, wherein the second data files are replicated copies of the first data files;

detecting an interruption in the data transfer between at least the first storage device and the one or more second storage devices, and based on the detection of the interruption;

comparing the first set of changes associated with the first storage device with the second set of changes associated with the second storage device to identify missing change data; and

updating the second data files on the second storage device by copying updated first data files from the first storage device to the second storage device based on the missing change data.

12. The method of claim 11 further comprising comparing record identifier numbers in the first set of changes with record identifier numbers in the second set of changes.

13. The method of claim 12 further comprising identifying the updated first data files of the first storage device using the record identifier numbers.

14. The method of claim 12 wherein the record identifier numbers of the first and second set of changes include an update sequence number.

15. The method of claim 11 wherein the updated first data files include a highest update sequence number.

16. The method of claim 12 wherein the record identifier numbers of the first and second set of changes include a file reference number.