Apparatus and methods for copying a logical object to a primary storage device using a map of storage locations

• US 6,385,706 B1
• Filed: 12/31/1998
• Issued: 05/07/2002
• Est. Priority Date: 12/31/1998
• Status: Expired due to Term

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Cakeljic, Zoran, Tamer, Philip, Ofek, Yuval
• Primary Examiner(s): Kim, Matthew M.
• Assistant Examiner(s): Vital, Pierre M
• Application Number:
  US09/223,896
• Time in Patent Office: 1,223 Days
• Field of Search: 711/112-113, 711/162, 711/202, 707/204
• US Class Current: 711/162
• 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: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

Method and apparatus for restoring copies of a logical object to a primary computer storage device are disclosed. A copy of the logical object is provided, physical blocks of memory in the primary storage device are allocated, a map of the data blocks will be copied to the physical blocks of the primary storage devices created. The copying may then occur using the created map. The copy of the logical object may be an abstract bloc set, which includes data blocks of the logical object potentially out of order and metadata identifying relative position of the data blocks.

Claims

1. A method of copying a logical object to a primary storage device, the method comprising steps of:

providing a copy of the logical object, the copy including data blocks of the logical object;

allocating physical blocks of memory in the primary storage device to store the logical object;

identifying respective locations of the physical blocks;

creating an abstract block set, including a map of the data blocks of the copy to the identified locations of the physical blocks of the primary storage device and information relating to an order of the data blocks in the logical object; and

copying the data blocks to the physical blocks, based on the map.

2. The method of claim 1, wherein the primary storage device is a cached disk array.

3. The method of claim 1, wherein the step of providing comprises a step of reading the copy from a secondary storage device.

4. The method of claim 1, wherein the copy of the logical object is an abstract block set.

5. The method of claim 1, wherein the step of creating a map comprises a step of creating a table, the table including entries specifying physical addresses of the allocated physical blocks.

6. The method of claim 5, wherein the table entries specify extents of allocated physical blocks.

7. The method of claim 5, wherein each entry has corresponding information to identify one or more corresponding data blocks of the copy of the logical object.

8. The method of claim 7, wherein the corresponding information comprises a physical address of a primary storage device on which the logical object had been stored.

9. The method of claim 8, wherein the step of providing comprises a step of reading the copy from a secondary storage device.

10. A method of copying a logical object to a primary storage device, the method comprising steps of:

providing an abstract block set copy of the logical object, the copy including data blocks of the logical object and information relating to an order of the data blocks in the logical object;

allocating physical blocks of memory in the primary storage device to store the logical object;

mapping the data blocks of the copy to the physical blocks of the primary storage device; and

copying the data blocks to the physical blocks, based on the mapping.

11. The method of claim 10, wherein the primary storage device is a cached disk array.

12. The method of claim 10, wherein the step of providing comprises a step of reading the abstract block set from a secondary storage device.

13. The method of claim 10, wherein the step of mapping comprises a step of creating a table, the table including entries specifying physical addresses of the allocated physical blocks.

14. The method of claim 13, wherein the table entries specify extents of allocated physical blocks.

15. The method of claim 13, wherein each entry has corresponding information to identify one or more corresponding data blocks of the abstract block set.

16. The method of claim 15, wherein the corresponding information comprises a physical address of a primary storage device on which the logical object had been stored.

17. The method of claim 16, wherein the step of providing comprises a step of reading the abstract block set from a secondary storage device.

18. The method of claim 10, wherein the abstract block set comprises metadata including information sufficient to distinguish the location in the logical object of the data blocks of the abstract block set.

19. The method of claim 18, wherein the metadata comprises

a plurality of labels, each label associated with one or more of the data blocks and

a table associating the labels with a relative position in the logical object.

20. The method of claim 18, wherein the metadata comprises physical memory addresses corresponding to the location of logical data blocks of the logical object stored in a primary storage device.

21. The method of claim 20, wherein the metadata comprises

a physical address associated with an extent of physical data blocks storing the logical data blocks, and

a table specifying the relative position of the extents in the logical object.

22. A computer storage device, comprising:

a memory including a plurality of physical data blocks;

means for receiving a mapping of data blocks of an abstract block set to a set of the physical data blocks, the abstract block set including information relating to an order of the data blocks in a logical object; and

means for storing the data blocks on the physical blocks, based on the mapping.

23. The computer storage device of claim 22, further comprising means for mapping the data blocks of the abstract block set to the set of the physical data blocks.