UPDATING METADATA IN A LOGICAL VOLUME ASSOCIATED WITH A STORAGE CONTROLLER

• US 20080005146A1
• Filed: 06/29/2006
• Published: 01/03/2008
• Est. Priority Date: 06/29/2006
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kubo, Robert Akira, Kalos, Matthew Joseph
• Granted Patent: US 8,140,785 B2
• Time in Patent Office: Days
• US Class Current: 707/102
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

Provided are a method, system, and article of manufacture for updating metadata in a logical volume associated with a storage controller. A data structure is generated indicating data units in a volume whose metadata is to be updated. An operation is initiated to update the metadata for data units indicated in the data structure. Indication is made in the data structure that the metadata for one data unit has been updated in response to updating the metadata for the data unit. An Input/Output (I/O) request is received to one data unit in the volume while the metadata for the data units indicated in the data structure is being updated. A determination is made, in response to the I/O request, from the data structure whether the metadata for the requested data unit was updated. The metadata for the requested data unit is updated in response to determining that the metadata for the requested data unit has not been updated. The I/O request is executed against the requested data unit.

Claims

1. A method, comprising:

generating a data structure indicating data units in a volume whose metadata is to be updated;

initiating an operation to update the metadata for data units indicated in the data structure;

indicating in the data structure that the metadata for one data unit has been updated in response to updating the metadata for the data unit;

receiving an Input/Output (I/O) request to one data unit in the volume while the metadata for the data units indicated in the data structure is being updated;

determining, in response to the I/O request, from the data structure whether the metadata for the requested data unit was updated;

updating the metadata for the requested data unit in response to determining that the metadata for the requested data unit has not been updated; and

executing the I/O request against the requested data unit.

2. The method of claim 1, wherein the I/O request is executed against the requested data unit in response to updating the metadata for the data unit or determining that the data structure indicates that the metadata for the data unit has been updated.

3. The method of claim 1, wherein the I/O request comprises a read request, wherein the metadata is updated before returning the requested data in response to determining that the metadata for the requested data unit has not been updated.

4. The method of claim 1, wherein updating the metadata for one data unit as part of the operation initiated to update the metadata for the data unit indicated in the data structure comprises:

determining whether the data structure indicates that the metadata for the data unit being processed has been updated; and

updating the metadata for the data unit in response to determining that the data structure indicates that the metadata has not been updated.

5. The method of claim 1, wherein the volume including the data units indicated in the data structure is in a storage device configured for use with a first storage server, further comprising:

associating the volume in the storage device with a second storage server for use with the second storage server.

6. The method of claim 5, wherein associating the volume with the second storage server, comprises:

determining a volume number to assign to the volume in the storage device, wherein the metadata is updated to indicate the determined volume number for the volume.

7. The method of claim 1, wherein the data structure comprises a point-in-time copy relationship indicating the data units in the volume whose metadata is to be updated, wherein the point-in-time copy operation updates the metadata for the indicated data units without copying the data units.

8. The method of claim 7, further comprising:

configuring the copy relationship to have a source and target volumes point to a same physical location, wherein data units indicated in the copy relationship as not copied from the source volume to the target volume have not had their metadata updated and wherein data units indicated as copied from the source volume to the target volume have had their metadata updated.

9. A system, comprising:

a data structure indicating data units in a volume whose metadata is to be updated;

an Input/Output (I/O) manager executed to perform operations, the operations comprising;

initiating an operation to update the metadata for data units indicated in the data structure;

indicating in the data structure that the metadata for one data unit has been updated in response to updating the metadata for the data unit;

receiving an I/O request to one data unit in the volume while the metadata for the data units indicated in the data structure is being updated;

determining, in response to the I/O request, from the data structure whether the metadata for the requested data unit was updated;

updating the metadata for the requested data unit in response to determining that the metadata for the requested data unit has not been updated; and

executing the I/O request against the requested data unit.

10. The system of claim 9, wherein updating the metadata for one data unit as part of the operation initiated to update the metadata for the data unit indicated in the data structure comprises:

determining whether the data structure indicates that the metadata for the data unit being processed has been updated; and

updating the metadata for the data unit in response to determining that the data structure indicates that the metadata has not been updated.

11. The system of claim 9, wherein the volume including the data units indicated in the data structure is in a storage device configured for use with a first storage server, wherein the operations further comprise:

associating the volume in the storage device with a second storage server for use with the second storage server.

12. The system of claim 9, wherein the data structure comprises a point-in-time copy relationship indicating the data units in the volume whose metadata is to be updated, wherein the point-in-time copy operation updates the metadata for the indicated data units without copying the data units.

13. An article of manufacture implementing code, wherein the code causes operations to be performed, the operations comprising:

generating a data structure indicating data units in a volume whose metadata is to be updated;

initiating an operation to update the metadata for data units indicated in the data structure;

indicating in the data structure that the metadata for one data unit has been updated in response to updating the metadata for the data unit;

receiving an Input/Output (I/O) request to one data unit in the volume while the metadata for the data units indicated in the data structure is being updated;

determining, in response to the I/O request, from the data structure whether the metadata for the requested data unit was updated;

updating the metadata for the requested data unit in response to determining that the metadata for the requested data unit has not been updated; and

executing the I/O request against the requested data unit.

14. The article of manufacture of claim 13, wherein the I/O request is executed against the requested data unit in response to updating the metadata for the data unit or determining that the data structure indicates that the metadata for the data unit has been updated.

15. The article of manufacture of claim 13, wherein the I/O request comprises a read request, wherein the metadata is updated before returning the requested data in response to determining that the metadata for the requested data unit has not been updated.

16. The article of manufacture of claim 13, wherein updating the metadata for one data unit as part of the operation initiated to update the metadata for the data unit indicated in the data structure comprises:

determining whether the data structure indicates that the metadata for the data unit being processed has been updated; and

updating the metadata for the data unit in response to determining that the data structure indicates that the metadata has not been updated.

17. The article of manufacture of claim 13, wherein the volume including the data units indicated in the data structure is in a storage device configured for use with a first storage server, wherein the operations further comprise:

associating the volume in the storage device with a second storage server for use with the second storage server.

18. The article of manufacture of claim 17, wherein associating the volume with the second storage server, comprises:

determining a volume number to assign to the volume in the storage device, wherein the metadata is updated to indicate the determined volume number for the volume.

19. The article of manufacture of claim 13, wherein the data structure comprises a point-in-time copy relationship indicating the data units in the volume whose metadata is to be updated, wherein the point-in-time copy operation updates the metadata for the indicated data units without copying the data units.

20. The article of manufacture of claim 13, wherein the operations further comprise:

configuring the copy relationship to have a source and target volumes point to a same physical location, wherein data units indicated in the copy relationship as not copied from the source volume to the target volume have not had their metadata updated and wherein data units indicated as copied from the source volume to the target volume have had their metadata updated.