Emulated storage system

• US 8,938,595 B2
• Filed: 06/29/2007
• Issued: 01/20/2015
• Est. Priority Date: 08/05/2003
• Status: Active Grant

• Current Assignee: Hitachi Vantara, LLC (Hitachi, Ltd.)
• Original Assignee: Sepaton Incorporated (Hitachi, Ltd.)
• Inventors: Sandorfi, Miklos, Reiter, Timmie G.
• Primary Examiner(s): Li, Aimee
• Assistant Examiner(s): Talukdar, Arvind
• Application Number:
  US11/771,245
• Publication Number:
  US 20080016131A1
• Time in Patent Office: 2,762 Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process
• CPC Class Codes: G06F 12/02 Addressing or allocation; Relocation program address sequencing G06F9/00; arrangements for selecting an address in a digital store G11C8/00

Abstract

A method for removing redundant data from a backup storage system is presented. In one example, the method may include identifying a first back-up data object, identifying a second back-up data object, detecting a first portion of the first back-up data object that is a copy of a second portion of the second back-up data object, and replacing the second portion with a pointer to the first portion.

Claims

1. A method for removing redundant data from a backup storage system implementing a forward referencing scheme, the method comprising:

storing, by a back-up application, a more recent back-up data object at a first physical location, the more recent back-up data object having been backed-up more recently than a less recent back-up data object that is distinct from the more recent back-up data object and that is stored at a second physical location different from the first physical location, the more recent back-up data object including a first redundant portion and a first unique portion, the less recent back-up data object including a second redundant portion and a second unique portion, the first unique portion including data different from the second unique portion;

identifying the less recent back-up data object created by the back-up application, the less recent back-up data object having been backed-up less recently than the more recent back-up data object;

detecting that the first redundant portion is a copy of the second redundant portion;

replacing the second redundant portion with a pointer to the first redundant portion; and

accessing, via the pointer to the first redundant portion by the back-up application, the more recent back-up data object at the first physical location.

2. The method according to claim 1, wherein replacing the second redundant portion with the pointer to the first redundant portion comprises:

creating a copy of the less recent back-up data object excluding the second redundant portion and including a pointer to the first redundant portion; and

deleting the less recent back-up data object.

3. The method according to claim 2, further comprising validating that the copy of the less recent back-up data object represents the same data as the less recent back-up data object.

4. The method according to claim 1, further comprising identifying at least one more recent characteristic of data object metadata;

wherein storing the more recent back-up data object includes storing a more recent back-up data object associated with data object metadata having the at least one more recent characteristic; and

wherein identifying the less recent back-up data object includes identifying a less recent back-up data object associated with data object metadata having the at least one more recent characteristic.

5. The method according to claim 4, wherein identifying the at least one more recent characteristic of data object metadata includes:

identifying a location in primary storage associated with the more recent back-up data object; and

identifying a location in primary storage associated with the less recent back-up data object.

6. The method according to claim 4, wherein identifying the at least one more recent characteristic of data object metadata includes:

identifying a software application associated with the more recent back-up data object; and

identifying a software application associated with the less recent back-up data object.

7. The method according to claim 4, wherein identifying the at least one more recent characteristic of data object metadata includes:

identifying a back-up policy associated with the more recent back-up data object; and

identifying a back-up policy associated with the less recent back-up data object.

8. The method according to claim 4, wherein identifying the at least one more recent characteristic of data object metadata includes:

identifying at least one more recent characteristic of data object metadata that was stored while the more recent back-up data object was being backed-up; and

identifying at least one more recent characteristic of data object metadata that was stored while the less recent back-up data object was being backed-up.

9. The method according to claim 1, wherein detecting the first redundant portion includes detecting a first redundant portion using metadata associated with the more recent back-up data object and metadata associated with the less recent back-up data object.

10. The method according to claim 9, wherein detecting the first redundant portion using metadata includes detecting a first redundant portion using metadata stored in a relational database.

11. The method according to claim 1, wherein storing the more recent back-up data object includes storing a more recent data file;

and

wherein identifying the less recent back-up data object includes identifying a less recent data file.

12. A computer-readable medium having computer-readable signals stored thereon that define instructions that, as a result of being executed by a computer, instruct the computer to perform the method of claim 1.

13. The method according to claim 1, wherein the method is executed in a grid computing environment.

14. The method according to claim 1, wherein the method is executed on a backup storage system while data is not being backed-up to the back-up storage system.

19. The method according to claim 4, further comprising identifying at least one less recent characteristic of data object metadata;

wherein storing the more recent back-up data object includes storing a third portion of the more recent back-up data object that is associated with data object metadata having the at least one less recent characteristic, the method further comprising excluding the third portion from additional processing.

20. The method according to claim 1, wherein detecting the first redundant portion includes selecting a technique for locating redundant data based on metadata associated with the more recent back-up data object.

21. The method according to claim 20, wherein selecting the technique for locating redundant data includes selecting a technique for locating redundant data that uses metadata associated with the more recent back-up data object.

22. The method according to claim 20, wherein selecting the technique for locating redundant data includes selecting a technique for locating redundant data that uses data included in the more recent back-up data object.

15. A method comprising:

storing, by a back-up application, a more recent back-up data object at a first physical location, the more recent back-up data object being associated with a software application and having been backed-up more recently than a less recent back-up data object that is distinct from the more recent back-up data object and that is stored at a second physical location different from the first physical location, the more recent back-up data object including a first redundant portion and a first unique portion, the less recent back-up data object including a second redundant portion and a second unique portion, the first unique portion including data different from the second unique portion;

identifying the less recent back-up data object created by the back-up application and associated with the software application, the less recent back-up data object having been backed-up less recently than the more recent back-up data object;

detecting, using a pattern of data distribution associated with the software application, that the first redundant portion is a copy of the second redundant portion, the pattern of data distribution being located within the more recent back-up data object and the less recent data back-up object;

replacing the second redundant portion with a pointer to the first redundant portion; and

accessing, via the pointer to the first redundant portion by the back-up application, the more recent back-up data object at the first physical location.

16. A computer-readable medium having computer-readable signals stored thereon that define instructions that, as a result of being executed by a computer, instruct the computer to perform the method of claim 15.

17. A system comprising:

back-up storage media storing a plurality of back-up data objects created by a back-up application and including a more recent back-up data object including more recent data and a less recent back-up data object that is distinct from the more recent back-up data object and that includes less recent data, the more recent back-up data object including a first redundant portion and a first unique portion, the less recent back-up data object including a second redundant portion and a second unique portion, the first unique portion including data different from the second unique portion; and

a controller configured to;

store the more recent back-up data object at a first physical location that is different from a second physical location at which the less recent back-up data object is stored;

identify that the first redundant portion is a copy of the second redundant portion;

replace the second redundant portion with a pointer to the first redundant portion; and

access via the pointer to the first redundant portion the more recent back-up data object at the first physical location.

18. The system according to claim 17, wherein the controller is further configured to replace the second redundant portion by creating a copy of the less recent back-up data object excluding the second redundant portion and including a pointer to the first redundant portion.

23. The system according to claim 17, wherein the more recent data is newer than the less recent data.