SYSTEMS AND METHODS FOR RETAINING AND USING DATA BLOCK SIGNATURES IN DATA PROTECTION OPERATIONS

• US 20120084518A1
• Filed: 12/30/2010
• Published: 04/05/2012
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: CommVault Systems Incorporated
• Original Assignee: CommVault Systems Incorporated
• Inventors: Vijayan, Manoj Kumar, Attarde, Deepak Raghunath
• Granted Patent: US 8,572,340 B2
• Time in Patent Office: Days
• US Class Current: 711/162
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 11/1466 to make the backup process non-disruptive
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0641 De-duplication techniques
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0683 Plurality of storage devices
• CPC Class Codes: H05K 999/99 dummy group

Abstract

A system according to certain embodiments associates a signature value corresponding to a data block with one or more data blocks and a reference to the data block to form a signature/data word corresponding to the data block. The system further logically organizes the signature/data words into a plurality of files each comprising at least one signature/data word such that the signature values are embedded in the respective file. The system according to certain embodiments reads a previously stored signature value corresponding to a respective data block for sending from a backup storage system having at least one memory device to a secondary storage system. Based on an indication as to whether the data block is already stored on the secondary storage system, the system reads the data block from the at least one memory device for sending to the secondary storage system if the data block exists on the secondary storage system, wherein the signature value and not the data block is read from the at least one memory device if the data block exists on the secondary storage system.

Claims

1. A method for storing data at a backup storage system, comprising:

for each of a plurality of data blocks involved in a backup storage operation, with one or more processors, associating a signature value corresponding to the data block with one or more of the data blocks and a reference to the data block to form a signature/data word corresponding to the data block; and

logically organizing the signature/data words into a plurality of files each comprising at least one signature/data word such that the signature values are embedded in the respective file.

2. The method of claim 1, wherein the associating comprises logically associating the signature values corresponding to the data block with one or more of the data blocks and a reference to the data block.

3. The method of claim 1, wherein the associating comprises storing the signature values corresponding to the data block in memory space that is logically contiguous with one or more of the data blocks and a reference to the data block.

4. The method claim 1, further comprising, in response to an instruction to copy at least one of the files to a secondary backup storage system, and for each signature/data word in the at least one of the files:

reading the signature value;

sending the signature value to the secondary backup storage system;

receiving an indication as to whether the data block corresponding to the signature value exists at the secondary backup storage system; and

reading the data block corresponding to the signature value if the signature value does not exist at the secondary backup storage system, wherein the data block is not read if the signature value does exist at the secondary backup storage system.

5. The method of claim 4, wherein the reading the signature value further comprises traversing to the respective signature/data word in the file and extracting the signature value for reading without reading the data block in the respective signature/data word.

6. The method of claim 5, wherein the reading the data block further comprises traversing to the respective signature/data word in the file and extracting the data block for reading using the reference to the data block in the signature/data word.

7. The method of claim 1, wherein the signature/data words corresponding to deduplicated data blocks comprise the signature value corresponding to the respective data block and a reference to the respective data block, and not the respective data block itself.

8. A system for storing data at a backup storage system, comprising:

at least one memory device;

a data packaging module executing in one or more processors and configured to;

for each of a plurality of data blocks involved in a backup storage operation, associate a signature value corresponding to the data block with one or more of the data blocks and a reference to the data block to form a signature/data word corresponding to the data block; and

logically organize the signature/data words into a plurality of files each comprising at least one signature/data word such that the signature values are embedded in the respective file.

9. The system of claim 8, wherein the data packaging module logically associates the signature values corresponding to the data block with one or more of the data blocks and a reference to the data block to form the signature/data word.

10. The system of claim 8, wherein the data packaging module stores the signature values corresponding to the data block in memory space that is logically contiguous with one or more of the data blocks and a reference to the data block.

11. The system of claim 8, further comprising a copy management module configured to, in response to an instruction to copy at least one of the files to a secondary backup storage system, and for each signature/data word in the at least one of the files:

read the signature value;

send the signature value to the secondary backup storage system;

receive an indication as to whether the data block corresponding to the signature value exists at the secondary backup storage system; and

read the data block corresponding to the signature value if the signature value does not exist at the secondary backup storage system, wherein the data block is not read if the signature value does exist at the secondary backup storage system.

12. The system of claim 11, wherein the copy management module is configured to read the signature value by traversing to the respective signature/data word in the file and extracting the signature value for reading without reading the data block in the respective signature/data word.

13. The system of claim 11, wherein the copy management module is configured to read the data block by traversing to the respective signature/data word in the file and extracting the data block for reading using the reference to the data block in the signature/data word.

14. The system of claim 8, wherein the signature/data words corresponding to deduplicated data blocks comprise the signature value corresponding to the respective data block and a reference to the respective data block, and not the respective data block itself.

15. A method for storing data at a storage system, comprising:

for each of a plurality of data blocks involved in a storage operation, with one or more processors, associating a signature value corresponding to the data block with one or more of the data blocks and a reference to the data block to form a signature/data word corresponding to the data block; and

logically organizing the signature/data words into a plurality of files each comprising at least one signature/data word such that the signature values are embedded in the respective file.