Creating a backup volume using a data profile of a host volume

• US 20040002999A1
• Filed: 03/17/2003
• Published: 01/01/2004
• Est. Priority Date: 03/25/2002
• Status: Active Grant

• Current Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Original Assignee: Quantum Corporation (Chi Ko Investment Co., Ltd.)
• Inventors: Rand, David Leroy
• Granted Patent: US 7,185,031 B2
• Time in Patent Office: Days
• US Class Current: 707/104.1
• CPC Class Codes: G06F 11/1451 by selection of backup contents
• CPC Class Codes: G06F 11/1464 for networked environments
• CPC Class Codes: G06F 2201/83 the solution involving signatures
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing
• CPC Class Codes: Y10S 707/99953 Recoverability
• CPC Class Codes: Y10S 707/99955 Archiving or backup

Abstract

A backup volume on a backup system is created/updated by reading data stored on a host volume on a host system. A data profile for the host volume is generated based on the read data, where the data profile characterizes the data stored on the host volume. The data profile is sent to the backup system, and data that does not need to be obtained from the host system is determined on the backup system based on the data profile.

Claims

1. A method of creating/updating a backup volume based on a host volume, the method comprising:

reading data stored on the host volume on a host system;

generating a data profile for the host volume based on the read data,

wherein the data profile characterizes the data stored on the host volume;

sending the data profile to a backup system; and

determining on the backup system data that does not need to be obtained from the host system based on the data profile.

2. The method of claim 1, wherein the data stored on the host volume includes a plurality of data blocks of a predetermined length, and wherein generating a data profile includes:

assigning a block number to a data block; and

assigning a block state to the data block, wherein the block state indicates whether the data block is allocated, unallocated, used, or unused.

3. The method of claim 2, wherein determining comprises:

if the block state of a data block indicates that the data block is unallocated and unused, determining that the data block does not need to be obtained from the host system.

4. The method of claim 3, wherein the block state indicates whether the data block contains data corresponding to a common data pattern, and wherein determining comprises:

if the block state of a data block indicates that the data contained in the data block corresponds to a common data pattern, determining that the data block does not need to be obtained from the host system.

5. The method of claim 1, wherein the data stored on the host volume includes a plurality of data blocks of a predetermined length, and wherein generating a data profile includes:

assigning a block number to a data block; and

assigning a check value to the data block, wherein the check value is generated based on the data contained in the data block.

6. The method of claim 5, wherein determining comprises:

generating a check value for a data block in the backup volume corresponding to a block number in the data profile;

comparing the generated check value with the check value corresponding to the block number in the data profile; and

if the check values are the same, determining that the data block does not need to be obtained from the host system.

7. The method of claim 5, further comprising:

assigning a check method code to the data block, wherein the check method code corresponds to a type of check method used to generate the check value.

8. The method of claim 1 further comprising:

setting a time marker corresponding to a time when the backup volume was first created.

9. The method of claim 8 further comprising:

determining a time interval when the backup volume was unavailable.

10. The method of claim 8 further comprising:

determining on the backup system data that needs to be obtained from the host system based on the data profile;

obtaining from the host system the data determined to be needed; and

assigning the obtained data the time marker.

11. A method of creating/updating a backup volume based on a host volume, the method comprising:

reading data stored on the host volume on a host system;

generating a data profile for the host volume based on the read data,

wherein the data profile characterizes the data stored on the host volume; and

sending the data profile to a backup system,

wherein the data profile is used by the backup system to determine data that needs to be obtained from the host system.

12. The method of claim 11, wherein the data stored on the host volume includes a plurality of data blocks, and wherein generating a data profile comprises:

assigning a block number to a data block; and

assigning a block state to the data block,

wherein the block state is used by the backup system to determine if the data block needs to be obtained from the host system.

13. The method of claim 12, wherein assigning a block state comprises:

assigning a first block state if the data block is unallocated and unused;

assigning a second block state if the data block includes all zeros; and

assigning a third block state if the data block includes all ones,

wherein the first, second, and third block states indicate that the data block does not need to be obtained from the host system.

14. The method of claim 11, wherein the data stored on the host volume includes a plurality of data blocks, and wherein generating a data profile comprises:

assigning a block number to a data block; and

assigning a check value to the data block,

wherein the block state is used by the backup system to determine if the data block needs to be obtained from the host system.

15. The method of claim 14, wherein assigning a check value comprises:

generating a check value for the data block based on data contained in the data block on the host volume.

16. The method of claim 14, further comprising:

assigning a check method code to the data block, wherein the check method code corresponds to a type of check method used to generate the check value.

17. A method of creating/updating a backup volume based on a host volume, the method comprising:

receiving a data profile from a host system,

wherein the data profile was generated by the host system based on data stored on the host volume on the host system, and

wherein the data profile characterizes the data stored on the host volume; and

examining the data profile to determine data that needs to be obtained from the host system.

18. The method of claim 17, wherein the data profile comprises:

a block number for a data block stored on the host volume; and

a block state for the data block indicating whether the data block needs to be obtained from the host system.

19. The method of claim 18, wherein examining the data profile comprises:

examining the block state for the data block;

determining if the block state corresponds to a first block state, which indicates that the data block in the host volume was unallocated and unused;

determining if the block state corresponds to a second block state, which indicates that the data block in the host volume contained all zeros;

determining if the block state corresponds to a third block state, which indicates that the data block in the host volume contained all ones; and

when the block state is determined to correspond to the first, second, or third state, determining that the data block does not need to be obtained from the host system.

20. The method of claim 17, wherein the data profile comprises:

a block number for a data block stored on the host volume; and

a check value for the data block.

21. The method of claim 20, wherein examining the data profile comprises:

generating a check value for a data block in the backup volume corresponding to the block number in the data profile;

comparing the generated check value with the check value corresponding to the block number in the data profile; and

if the check values are different, determining that the data block needs to be obtained from the host system.

22. The method of claim 20, wherein the data profile further comprises:

a check method code corresponding to a type of check method used to generate the check value.

23. A system of creating/updating a backup volume based on a host volume, the system comprising:

a host system having the host volume, wherein the host system is configured to;

read data stored on the host volume;

generate a data profile that characterizes the read data; and

a backup system having the backup volume, wherein the data profile is sent by the host system to the backup system, and wherein the backup system is configured to;

examine the data profile to determine data that needs to be obtained from the host system.

24. A computer-readable storage medium containing computer executable code to create/update a backup volume on a backup system by instructing a host system to operate as follows:

reading data stored on a host volume on the host system;

generating a data profile for the host volume based on the read data,

wherein the data profile characterizes the data stored on the host volume; and

sending the data profile to the backup system,

wherein the data profile is used by the backup system to determine data that needs to be obtained from the host system.

25. A computer-readable storage medium containing computer executable code to create/update a backup volume by instructing a backup system to operate as follows:

receiving a data profile from a host system,

wherein the data profile was generated by the host system based on data stored on a host volume on the host system, and

wherein the data profile characterizes the data stored on the host volume; and

examining the data profile to determine data that needs to be obtained from the host system.