CREATING A RESTORE COPY FROM A COPY OF A FULL COPY OF SOURCE DATA IN A REPOSITORY THAT IS AT A DIFFERENT POINT-IN-TIME THAN A RESTORE POINT-IN-TIME OF A RESTORE REQUEST

• US 20150227438A1
• Filed: 02/07/2014
• Published: 08/13/2015
• Est. Priority Date: 02/07/2014
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Jaquette, Glen A., Kishi, Gregory T.
• Granted Patent: US 11,194,667 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• 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

Abstract

Provided are a computer program product, system, and method for creating a restore copy from a copy of a full copy of source data in a repository that is at a different point-in-time than a restore point-in-time of a restore request. A repository has a full copy of source data as of a full copy point-in-time and for each of a plurality of point-in-time copies at different point-in-times of the source data, change information indicating changed data in the source data that changed between the point-in-time of the point-in-time copy and a subsequent point-in-time, and changed point-in-time data comprising data in the source data as of the point-in-time of the point-in-time copy indicated in the change information as changed. A point-in-time copy of the full copy is created in response to a restore request and returned as a restore copy to the restore request.

Claims

1. A computer program product for maintaining source data in a repository, wherein the computer program product comprises a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause operations, the operations comprising:

maintaining a repository having a full copy of source data as of a full copy point-in-time and for each of a plurality of point-in-time copies at different point-in-times of the source data, change information indicating changed data in the source data that changed between the point-in-time of the point-in-time copy and a subsequent point-in-time, and changed point-in-time data comprising data in the source data as of the point-in-time of the point-in-time copy indicated in the change information as changed;

receiving a restore request to restore the source data as of a restore point-in-time different from the point-in-time of the full copy;

creating a point-in-time copy of the full copy; and

returning the created point-in-time copy of the full copy as a restore copy to the restore request, wherein the restore copy has data as of a restore copy point-in-time comprising the point-in-time copy of the full copy which is different from the restore point-in-time.

2. The computer program product of claim 1, wherein the operations further comprise:

receiving a read request directed to requested data in the restore data;

determining from the change information for at least one of the point-in-time copies of the source data at a point-in-time from the restore point-in-time to the restore copy point-in-time whether the requested data in the restore copy is not at the restore point-in-time; and

returning the requested data from the changed point-in-time data for one of the point-in-time copies at a point-in-time from the restore point-in-time to the restore copy point-in-time in the repository in response to determining that the requested data in the restore copy is not at the restore point-in-time.

3. The computer program product of claim 2, wherein the operations further comprise:

returning the requested data from the restore copy in response to determining that the requested data in the restore copy is at the restore point-in-time.

4. The computer program product of claim 2, wherein the operations further comprise:

copying the requested data from the changed point-in-time data returned to the read request to the restore copy.

5. The computer program product of claim 2, wherein when multiple point-in-time copies provide changed point-in-time data for the requested data, the changed point-in-time data from the point-in-time copy having a point-in-time from the restore copy point-in-time to the restore point-in-time and closest in time to the restore point-in-time is returned as the requested data.

6. The computer program product of claim 2, wherein the operations further comprise:

generating consolidated change information indicating changed point-in-time data for the point-in-time copies from the restore point-in-time to the full copy point-in-time, wherein if there are changed point-in-time data for multiple point-in-time copies for one data unit in the source data, then the consolidated changed point-in-time data indicates the changed point-in-time data for the data unit for the point-in-time copy having a point-in-time closest to the restore point-in-time,

wherein returning the requested data from the changed point-in-time data for one of the point-in-time copies comprises returning the requested data from the changed point-in-time data indicated in the consolidated change information for the data unit.

7. The computer program product of claim 2, wherein the full copy point-in-time is at one of an earliest point-in-time, a latest point-in-time, and an intermediate point-in-time between the earliest and the latest point-in-times of the point-in-time copies of the source data in the repository.

8. The computer program product of claim 1, wherein the operations further comprise:

receiving writes directed to the restore copy;

applying the writes to update the restore copy;

receiving a read request for requested data in the restore copy updated by the writes;

returning data for the requested data from changed point-in-time data for one of the point-in-time copies in the repository to return requested data as of the restore point-in-time.

9. The computer program product of claim 1, wherein metadata for the restore copy indicates the restore point-in-time and the full copy point-in-time.

10. The computer program product of claim 1, wherein point-in-time copies of the full copy are created for multiple restore requests from multiple virtual machines, wherein for each of the virtual machines operations are performed comprising:

receiving a read request from a requesting virtual machine comprising one of the virtual machines directed to requested data in a restore copy for the requesting virtual machine;

determining from the change information for at least one of the point-in-time copies of the source data whether the requested data in the restore copy for the requesting virtual machine is not at the restore point-in-time; and

returning the requested data from the changed point-in-time data for one of the point-in-time copies in the repository to the requesting virtual machine in response to determining that the requested data in the restore copy is not at the restore point-in-time.

11. A system for maintaining source data in a repository, comprising:

a processor; and

a computer readable storage medium including program instructions executed by the processor to perform operations, the operations comprising;

maintaining a repository having a full copy of source data as of a full copy point-in-time and for each of a plurality of point-in-time copies at different point-in-times of the source data, change information indicating changed data in the source data that changed between the point-in-time of the point-in-time copy, and a subsequent point-in-time and changed point-in-time data comprising data in the source data as of the point-in-time of the point-in-time copy indicated in the change information as changed;

receiving a restore request to restore the source data as of a restore point-in-time different from the point-in-time of the full copy;

creating a point-in-time copy of the full copy; and

returning the created point-in-time copy of the full copy as a restore copy to the restore request, wherein the restore copy has data as of a restore copy point-in-time comprising the point-in-time copy of the full copy which is different from the restore point-in-time.

12. The system of claim 11, wherein the operations further comprise:

receiving a read request directed to requested data in the restore data;

determining from the change information for at least one of the point-in-time copies of the source data at a point-in-time from the restore point-in-time to the restore copy point-in-time whether the requested data in the restore copy is not at the restore point-in-time; and

returning the requested data from the changed point-in-time data for one of the point-in-time copies at a point-in-time from the restore point-in-time to the restore copy point-in-time in the repository in response to determining that the requested data in the restore copy is not at the restore point-in-time.

13. The system of claim 12, wherein the operations further comprise:

returning the requested data from the restore copy in response to determining that the requested data in the restore copy is at the restore point-in-time.

14. The system of claim 12, wherein the operations further comprise:

generating consolidated change information indicating changed point-in-time data for the point-in-time copies from the restore point-in-time to the full copy point-in-time, wherein if there are changed point-in-time data for multiple point-in-time copies for one data unit in the source data, then the consolidated changed point-in-time data indicates the changed point-in-time data for the data unit for the point-in-time copy having a point-in-time closest to the restore point-in-time,

wherein returning the requested data from the changed point-in-time data for one of the point-in-time copies comprises returning the requested data from the changed point-in-time data indicated in the consolidated change information for the data unit.

15. The system of claim 11, wherein the operations further comprise:

receiving writes directed to the restore copy;

applying the writes to update the restore copy;

receiving a read request for requested data in the restore copy updated by the writes;

returning data for the requested data from changed point-in-time data for one of the point-in-time copies in the repository to return requested data as of the restore point-in-time.

16. The system of claim 11, wherein point-in-time copies of the full copy are created for multiple restore requests from multiple virtual machines, wherein for each of the virtual machines operations are performed comprising:

receiving a read request from a requesting virtual machine comprising one of the virtual machines directed to requested data in a restore copy for the requesting virtual machine;

determining from the change information for at least one of the point-in-time copies of the source data whether the requested data in the restore copy for the requesting virtual machine is not at the restore point-in-time; and

returning the requested data from the changed point-in-time data for one of the point-in-time copies in the repository to the requesting virtual machine in response to determining that the requested data in the restore copy is not at the restore point-in-time.

17. A method, comprising:

maintaining a repository having a full copy of source data as of a full copy point-in-time and for each of a plurality of point-in-time copies at different point-in-times of the source data, change information indicating changed data in the source data that changed between the point-in-time of the point-in-time copy and a subsequent point-in-time, and changed point-in-time data comprising data in the source data as of the point-in-time of the point-in-time copy indicated in the change information as changed;

receiving a restore request to restore the source data as of a restore point-in-time different from the point-in-time of the full copy;

creating a point-in-time copy of the full copy; and

returning the created point-in-time copy of the full copy as a restore copy to the restore request, wherein the restore copy has data as of a restore copy point-in-time comprising the point-in-time copy of the full copy which is different from the restore point-in-time.

18. The method of claim 17, further comprising:

receiving a read request directed to requested data in the restore data;

determining from the change information for at least one of the point-in-time copies of the source data at a point-in-time from the restore point-in-time to the restore copy point-in-time whether the requested data in the restore copy is not at the restore point-in-time; and

returning the requested data from the changed point-in-time data for one of the point-in-time copies at a point-in-time from the restore point-in-time to the restore copy point-in-time in the repository in response to determining that the requested data in the restore copy is not at the restore point-in-time.

19. The method of claim 18, further comprising:

returning the requested data from the restore copy in response to determining that the requested data in the restore copy is at the restore point-in-time.

20. The method of claim 18, further comprising:

generating consolidated change information indicating changed point-in-time data for the point-in-time copies from the restore point-in-time to the full copy point-in-time, wherein if there are changed point-in-time data for multiple point-in-time copies for one data unit in the source data, then the consolidated changed point-in-time data indicates the changed point-in-time data for the data unit for the point-in-time copy having a point-in-time closest to the restore point-in-time,

wherein returning the requested data from the changed point-in-time data for one of the point-in-time copies comprises returning the requested data from the changed point-in-time data indicated in the consolidated change information for the data unit.

21. The method of claim 17, further comprising:

receiving writes directed to the restore copy;

applying the writes to update the restore copy;

receiving a read request for requested data in the restore copy updated by the writes;

returning data for the requested data from changed point-in-time data for one of the point-in-time copies in the repository to return requested data as of the restore point-in-time.

22. The method of claim 17, wherein point-in-time copies of the full copy are created for multiple restore requests from multiple virtual machines, wherein for each of the virtual machines operations are performed comprising:

receiving a read request from a requesting virtual machine comprising one of the virtual machines directed to requested data in a restore copy for the requesting virtual machine;

determining from the change information for at least one of the point-in-time copies of the source data whether the requested data in the restore copy for the requesting virtual machine is not at the restore point-in-time; and

returning the requested data from the changed point-in-time data for one of the point-in-time copies in the repository to the requesting virtual machine in response to determining that the requested data in the restore copy is not at the restore point-in-time.