Space-optimized backup set conversion

• US 7,941,619 B1
• Filed: 11/18/2004
• Issued: 05/10/2011
• Est. Priority Date: 11/18/2004
• Status: Active Grant

• Current Assignee: Veritas Technologies, LLC (Whitehouse Group Ltd.)
• Original Assignee: Symantec Operating Corporation (Gen Digital Inc.)
• Inventors: Rossi, Robert P.
• Primary Examiner(s): Thomas; Shane M
• Assistant Examiner(s): Birkhimer; Christopher D
• Application Number:
  US10/992,274
• Time in Patent Office: 2,364 Days
• Field of Search: 711/162, 711/161
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1458 Management of the backup or restore process

Abstract

A system for space-optimized backup set conversion may include a backup converter and a first sequence of backup images of a data source. Each backup image may be of a particular backup image type, such as a full image, a differential image, or an incremental image. The backup converter may be configured to convert the first sequence of backup images into a second sequence of backup images by converting a particular backup image of the first sequence into a transformed backup image of a different backup type. For example, a full image may be converted into either a differential image or an incremental image, and a differential image may be converted into an incremental image.

Claims

1. A system comprising:

a backup storage configured to store a first sequence of two or more backup images of a data source including a first full backup image representing a state of the data source at a first time T1 and a second full backup image representing the state of the data source at a second time T2; and

backup management software stored on a computer accessible storage medium, wherein the backup management software includes instructions that implement a backup converter executable to access the first full backup image and the second full backup image on the backup storage to create a first differential backup image representing the state of the data source at the time T2, wherein the backup converter is executable to create the first differential backup image by determining and storing data differences between the second full backup image and the first full backup image;

wherein the backup converter is further executable, in response to determining that a storage amount used to store the first sequence of two or more backup images exceeds a designated threshold, to;

create the first differential backup image; and

store the first differential backup image on the backup storage and to discard the second full backup image from the backup storage such that the second full backup image is no longer accessible anywhere on the backup storage, thereby allowing re-use of storage space made available on the backup storage a result of discarding the second full backup image while still retaining the first full backup image representing the state of the data source at the time T1 and the first differential image representing the state of the data source at the time T2 on the backup storage.

2. The system as recited in claim 1, wherein the backup converter is further executable to access a third full backup image of the first sequence representing the state of the data source at a time T3, wherein the backup converter is further executable to create a second differential backup image representing the state of the data source at the time T3 by determining and storing data differences between the third full backup image and the second full backup image.

3. The system as recited in claim 1, wherein the backup converter is further executable to access a third full backup image of the first sequence representing the state of the data source at a time T3 to create a first incremental backup image representing the state of the data source at the time T3.

4. The system as recited in claim 3, wherein the backup converter is further executable to create the first incremental backup image by determining and storing data differences between the third full backup image and the second full backup image.

5. The system as recited in claim 1, wherein the backup management software is executable to store the first sequence of two or more backup images on the backup storage by performing a plurality of successive backup operations on the data source.

6. The system as recited in claim 5, wherein the backup management software is executable to store the first sequence of two or more backup images on the backup storage according to a backup schedule.

7. A computer accessible storage medium storing backup management software including instructions executable to:

access a first full backup image and a second full backup image of a first sequence of backup images stored on a backup storage, wherein the first full backup image represents a state of a data source at a first time T1 and the second full backup image represents the state of the data source at a second time T2; and

in response to determining that a storage amount used to store the first sequence of two or more backup images exceeds a designated threshold;

create a first differential backup image representing the state of the data source at the time T2 by determining and storing data differences between the second full backup image and the first full backup image; and

store the first differential backup image on the backup storage and discard the second full backup image from the backup storage such that the second full backup image is no longer accessible anywhere on the backup storage, thereby allowing re-use of storage space made available on the backup storage a result of discarding the second full backup image while still retaining the first full backup image representing the state of the data source at the time T1 and the first differential image representing the state of the data source at the time T2 on the backup storage.

8. The computer accessible storage medium as recited in claim 7, wherein the backup management software is further executable to access a third full backup image of the first sequence representing the state of the data source at a time T3 to create a second differential backup image representing the state of the data source at the time T3 by determining and storing data differences between the third full backup image and the second full backup image.

9. The computer accessible storage medium as recited in claim 7, wherein the backup management software is further executable to access a third full backup image of the first sequence representing the state of the data source at a time T3 to create a first incremental backup image representing the state of the data source at the time T3.

10. The computer accessible storage medium as recited in claim 9, wherein the backup management software is further executable to create the first incremental backup image by determining and storing data differences between the third full backup image and the second full backup image.

11. The computer accessible storage medium as recited in claim 7, wherein the backup management software is further executable to store the first sequence of backup images on the backup storage by performing a plurality of successive backup operations on the data source.

12. The computer accessible storage medium as recited in claim 11, wherein the backup management software is further executable to store the first sequence of backup images on the backup storage according to a backup schedule.

13. A method comprising:

storing on a backup storage a first sequence of two or more backup images of a data source including a first full backup image representing a state of the data source at a first time T1 and a second full backup image representing the state of the data source at a second time T2; and

in response to determining that a storage amount used to store the first sequence of two or more backup images exceeds a designated threshold;

accessing the first full backup image and the second backup image on the backup storage; and

creating a first differential backup image representing the state of the data source at the time T2 by determining and storing data differences between the second full backup image and the first full backup image; and

storing the first differential backup image on the backup storage and discarding the second full backup image from the backup storage such that the second full backup image is no longer accessible anywhere on the backup storage, thereby allowing re-use of storage space made available on the backup storage a result of discarding the second full backup image while still retaining the first full backup image representing the state of the data source at the time T1 and the first differential image representing the state of the data source at the time T2 on the backup storage.

14. The method as recited in claim 13, further comprising:

accessing a third full backup image of the first sequence representing the state of the data source at a time T3; and

creating a second differential backup image representing the state of the data source at the time T3 by determining and storing data differences between the third full backup image and the second full backup image.

15. The method as recited in claim 13, further comprising storing the first sequence of two or more backup images on the backup storage by performing a plurality of successive backup operations on the data source.