System and method of applying incremental changes prior to initialization of a point-in-time copy

• US 7,809,691 B1
• Filed: 02/22/2005
• Issued: 10/05/2010
• Est. Priority Date: 02/22/2005
• Status: Active Grant

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Symantec Operating Corporation (NortonLifeLock Inc.)
• Inventors: Tawri, Deepak, Karmarkar, Kedar M., Krishnamurthy, Raghu
• Primary Examiner(s): To; Baoquoc N
• Application Number:
  US11/063,133
• Time in Patent Office: 2,051 Days
• Field of Search: 707/200, 707/202, 707/203, 707/204
• US Class Current: 707/674
• CPC Class Codes: G06F 11/1448 Management of the data involved in backup or backup restore
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/1658 Data re-synchronization of a redundant component, or initial sync of replacement, additional or spare unit
• CPC Class Codes: G06F 11/202 where processing functionality is redundant redundant communication control functionality G06F11/2005, redundant storage control functionality G06F11/2089

Abstract

Various systems and methods are disclosed for applying incremental changes prior to initialization of a point-in-time copy. For example, one method involves identifying an incremental change to information stored on a primary device. The incremental change is identified subsequent to a first point in time. The incremental change is applied to a first target device, prior to completing initialization of a second target device. The initialization of the second target device initializes the second target device as a point-in-time copy of the primary device. The point-in-time copy of the primary device is a copy of the primary device at the first point in time.

Claims

1. A method comprising:

identifying an incremental change to information stored on a primary device, wherein

the incremental change is identified subsequent to a first point in time;

applying the incremental change to a first target device, wherein

the incremental change is applied to the first target device prior to completing initialization of a second target device,

the initialization of the second target device initializes the second target device as a point-in-time copy of the primary device,

the point-in-time copy of the primary device is a copy of the primary device at the first point in time, and

the applying the incremental change to the first target device restores the first target device from an incremental backup of the primary device by virtue of the applying the incremental change to the first target device comprising

replicating the incremental change to the first target device;

restoring the primary device from a full backup of the primary device, wherein

the restoring the primary device from the full backup initializes the first target device as the point-in-time copy of the primary device, and

the first target device is a replica device; and

restoring the second target device from a full backup of the primary device, wherein

the restoring the second target device from a full backup of the primary device initializes the second target device as the point-in-time copy of the primary device.

2. The method of claim 1, wherein

the second target device is a snapshot of the replica device.

3. The method of claim 1, wherein

the first target device is the second target device.

4. The method of claim 3, wherein the restoring the second target device from a full backup of the primary comprises:

identifying whether a unit of data stored by the replica device has been modified by the applying the incremental change to the replica device; and

if the unit of data has not been modified, copying a value of the unit of data from the full backup of the primary device to the replica device.

5. The method of claim 4, wherein

the unit of data comprises one of a block, an extent, a portion of a file, and a file.

6. The method of claim 4, further comprising:

initializing the replica device at substantially the same time as applying the incremental change to the replica device.

7. The method of claim 1, further comprising:

initializing the second target device, wherein the initializing comprises performing a full backup of the primary device to the second target device, wherein

the first target device stores an incremental backup of the primary device,

the second target device stores the full backup of the primary device, and

the performing the full backup initializes the second target device as the point-in-time copy of the primary device.

8. The method of claim 7, wherein

the initializing is performed in parallel with the applying the incremental change to the first target device.

9. The method of claim 1, wherein

the first target device is the primary device.

10. The method of claim 9, wherein the restoring the primary device from the full backup comprises:

identifying whether a unit of data stored by the primary device has been modified due to the applying the incremental change to the primary device; and

if the unit of data has not been modified, copying a value of the unit of data from the full backup to the primary device.

11. The method of claim 9, wherein

the primary device is restored from the full backup subsequent to being restored from the incremental backup.

12. A system comprising:

a primary device;

a first target device, wherein the primary device and the first target device are communicatively coupled to one another;

a second target device, wherein the primary device and the second target device are communicatively coupled to one another;

means for identifying an incremental change to information stored on the primary device, wherein

the incremental change is identified subsequent to a first point in time;

means for applying the incremental change to the first target device, wherein

the means for applying the incremental change is configured to apply the incremental change to the first target device prior to completing initialization of the second target device,

the means for applying the incremental change to the first target device is configured to restore the primary device from an incremental backup of the primary device by virtue of the means for applying the incremental change to the first target device comprising

means for replicating the incremental change to the first target device,

the initialization of the second target device initializes the second target device as a point-in-time copy of the primary device, and

the point-in-time copy of the primary device is a copy of the primary device at the first point in time;

means for restoring the primary device from a full backup of the primary device, wherein

the means for restoring the primary device from the full backup is configured to initialize the first target device as the point-in-time copy of the primary device, and

the first target device is a replica device; and

means for restoring the second target device from a full backup of the primary device, wherein

the means for restoring is configured to initialize the second target device as the point-in-time copy of the primary device, and

the means for restoring comprises

means for identifying whether a unit of data stored by the replica device has been modified by the applying the incremental change to the replica device, and

means for copying a value of the unit of data from the full backup of the primary device to the replica device, if the unit of data has not been modified.

13. The system of claim 12, wherein

the first target device is the second target device.

14. The system of claim 12, further comprising:

means for initializing the second target device, wherein the means for initializing the second target device comprises means for performing a full backup of the primary device to the second target device, wherein

the first target device is configured to store an incremental backup of the primary device,

the second target device is configured to store the full backup of the primary device, and

the means for performing the full backup is configured to initialize the second target device as the point-in-time copy of the primary device.

15. The system of claim 12, wherein

the first target device is the primary device.

16. A computer readable storage medium comprising program instructions executable to:

identify an incremental change to information stored on a primary device, wherein

the incremental change is identified subsequent to a first point in time;

apply the incremental change to a first target device, wherein

the incremental change is applied to a first target device prior to completing initialization of a second target device,

the initialization of the second target device initializes the second target device as a point-in-time copy of the primary device,

the point-in-time copy of the primary device is a copy of the primary device at the first point in time, and

the applying the incremental change to the first target device restores the first target device from an incremental backup of the primary device by virtue of the applying the incremental change to the first target device comprising;

replicating the incremental change to the first target device, restore the primary device from a full backup of the primary device, wherein

the restoration of the primary device from the full backup initializes the first target device as the point-in-time copy of the primary device, and

the first target device is a replica device; and

restore the second target device from a full backup of the primary device, wherein

the restoration of the second target device from the full backup initializes the second target device as the point-in-time copy of the primary device,

the restoration of the second target device from the full backup comprises

identifying whether a unit of data stored by the replica device has been modified by the applying the incremental change to the replica device, and

if the unit of data has not been modified, copying a value of the unit of data from the full backup of the primary device to the replica device.

17. The computer readable storage medium of claim 16, wherein

the first target device is the second target device.

18. The computer readable storage medium of claim 16, wherein the program instructions are further executable to:

initialize the second target device, wherein

initializing the second target device comprises performing a full backup of the primary device to the second target device,

the first target device stores an incremental backup of the primary device,

the second target device stores the full backup of the primary device, and

performing the full backup initializes the second target device as the point-in-time copy of the primary device.

19. The computer readable storage medium of claim 16, wherein

the first target device is the primary device.

20. A system comprising:

a processor; and

a memory communicatively coupled to the processor, wherein the memory stores program instructions executable to;

identify an incremental change to information stored on a primary device, wherein

the incremental change is identified subsequent to a first point in time;

apply the incremental change to a first target device, wherein

the incremental change is applied to a first target device prior to completing initialization of a second target device,

the initialization of the second target device initializes the second target device as a point-in-time copy of the primary device,

the point-in-time copy of the primary device is a copy of the primary device at the first point in time,

the applying the incremental change to the first target device restores the first target device from an incremental backup of the primary device, and

the applying the incremental change to the first target device restores the first target device from an incremental backup of the primary device by virtue of the applying the incremental change to the first target device comprising

replicating the incremental change to the first target device;

restore the primary device from a full backup of the primary device, wherein

the restoration of the primary device from the full backup initializes the first target device as the point-in-time copy of the primary device, and

the first target device is a replica device; and

restore the primary device from a full backup of the primary device, wherein

the restoring the primary device from the full backup initializes the first target device as the point-in-time copy of the primary device.