Apparatus and method for instant copy of data

• US 20030005248A1
• Filed: 06/19/2001
• Published: 01/02/2003
• Est. Priority Date: 06/19/2000
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Storage Technology Corp (Oracle Corporation)
• Inventors: Milligan, Charles A., Selkirk, Stephen S.
• Granted Patent: US 6,779,095 B2
• Time in Patent Office: Days
• US Class Current: 711/165
• CPC Class Codes: G06F 11/2069 Management of state, configuration or failover
• 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 is provided to support dynamically changeable virtual mapping schemes in a data processing system. The present invention separates processing of data unit requirements from the selection of which storage subsystems to use for storage by using a storage methodologies inventory. A stored data management subsystem contains one or more hosts. A plurality of data storage elements is functionally coupled to the one or more hosts. The plurality of data storage elements is organized using a plurality of layers of mapping tables. The plurality of layers of mapping tables provides unique identification of location of the data such that individual data entries in a mapping table is variable and self-defining with respect to the amount of data managed. In addition, the present system provides various instant copy mechanisms for copying data upon receiving a write operation to either a source or copy data. The instant copy mechanisms may be selected based on the type of mapping originally used to store the data that is to be copied.

Claims

1. A method of performing an instant copy of data, comprising:

receiving a write operation to a data location in one of an initial physical storage area and an additional physical storage area;

performing an instant copy operation on the data location; and

writing new data to the data location in accordance with the write operation, wherein the instant copy operation includes generating a pointer to one of the new data and original data in the data location.

2. The method of claim 1, wherein the data location is in the initial physical storage area, and wherein the instant copy operation includes copying a portion of original data from the data location in the initial physical storage area to a second data location in the additional physical storage area in response to receiving the write operation.

3. The method of claim 2, wherein the pointer points to the portion of original data copied to the additional physical storage area.

4. The method of claim 1, wherein the data location is in the additional physical storage area.

5. The method of claim 4, wherein the instant copy operation includes not copying a portion of original data from the initial physical storage area to the additional physical storage area.

6. The method of claim 4, wherein the pointer points to new data written to the data location in the additional physical storage area.

7. The method of claim 1, wherein the initial physical storage area is a variable dynamically changeable mapping scheme storage area.

8. The method of claim 2, wherein the portion of original data has a size that is different with respect to other portions of data in the initial physical storage area.

9. The method of claim 1, wherein the pointer is generated in a pointer table of meta-data associated with the additional physical storage area.

10. The method of claim 8, further comprising storing the pointer and an associated size of the portion of original data in a meta-data data structure.

11. The method of claim 1, wherein the pointer is stored in a pointer table of meta-data having a plurality of pointers, and wherein the plurality of pointers include a pair of pointers representing a range of pointers that point to portions of original data that have not been changed by a write operation.

13. The computer program product of claim 12, wherein the data location is in the initial physical storage area, and wherein the second instructions for performing an instant copy operation include instructions for copying a portion of original data from the data location in the initial physical storage area to a second data location in the additional physical storage area in response to receiving the write operation.

14. The computer program product of claim 13, wherein the pointer points to the portion of original data copied to the additional physical storage area.

15. The computer program product of claim 12, wherein the data location is in the additional physical storage area.

16. The computer program product of claim 15, wherein the second instructions for performing the instant copy operation include instructions for not copying a portion of original data from the initial physical storage area to the additional physical storage area.

17. The computer program product of claim 15, wherein the pointer points to new data written to the data location in the additional physical storage area.

18. The computer program product of claim 12, wherein the initial physical storage area is a variable dynamically changeable mapping scheme storage area.

19. The computer program product of claim 13, wherein the portion of original data has a size that is different with respect to other portions of data in the initial physical storage area.

20. The computer program product of claim 12, wherein the second instructions for performing the instant copy operation include instructions for generating the pointer in a pointer table of meta-data associated with the additional physical storage area.

21. The computer program product of claim 19, wherein the second instructions for performing the instant copy operation include instructions for storing the pointer and an associated size of the portion of original data in a meta-data data structure.

22. The computer program product of claim 12, wherein the second instructions for performing the instant copy operation include instructions for storing the pointer in a pointer table of meta-data having a plurality of pointers, and wherein the plurality of pointers include a pair of pointers representing a range of pointers that point to portions of original data that have not been changed by a write operation.

12. A computer program product in a computer readable medium for performing an instant copy of data, comprising:

first instructions for receiving a write operation to a data location in one of an initial physical storage area and an additional physical storage area;

second instructions for performing an instant copy operation on the data location; and

third instructions for writing new data to the data location in accordance with the write operation, wherein the instant copy operation includes generating a pointer to one of the new data and original data in the data location.

23. An apparatus for performing an instant copy of data, comprising:

means for receiving a write operation to a data location in one of an initial physical storage area and an additional physical storage area;

means for performing an instant copy operation on the data location; and

means for writing new data to the data location in accordance with the write operation, wherein the instant copy operation includes generating a pointer to one of the new data and original data in the data location.