Storage Device and Method for Selective Data Compression

• US 20130205110A1
• Filed: 02/06/2012
• Published: 08/08/2013
• Est. Priority Date: 02/06/2012
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Kettner, Doron
• Granted Patent: US 8,918,579 B2
• Time in Patent Office: Days
• US Class Current: 711/170
• CPC Class Codes: H03M 7/6064 Selection of Compressor

Abstract

A storage device and method for selective data compression are provided. In one embodiment, a storage device determines whether data stored in a storage area in the storage device'"'"'s memory is suitable for compression. If the data is suitable for compression, the storage device compresses the data. The storage device then uses free memory space resulting from compressing the data for an internal storage device operation. Other embodiments are disclosed, and each of the embodiments can be used alone or together in combination.

Claims

1. A method for selective data compression, the method comprising:

performing the following in a storage device in communication with a host device, the storage device having a non-volatile memory;

determining whether data stored in a storage area in the memory is suitable for compression;

if the data is suitable for compression, compressing the data; and

using free memory space resulting from compressing the data for an internal storage device operation.

2. The method of claim 1, wherein determining whether data is suitable for compression comprises determining whether the data is backup data.

3. The method of claim 1, wherein determining whether data is suitable for compression comprises determining a compression efficiency for the data.

4. The method of claim 1, wherein determining whether data is suitable for compression comprises determining an access frequency of the data.

5. The method of claim 1 further comprising determining a compression algorithm to use to compress the data.

6. The method of claim 1 further comprising determining a schedule for compressing the data.

7. The method of claim 1 further comprising determining whether compressing the data would violate a rule.

8. The method of claim 7, wherein the rule is violated if a logical partition is reformatted.

9. The method of claim 7, wherein the rule is violated if a change is made to data that is frequently accessed or modified.

10. The method of claim 1, wherein a total exported capacity reported to the host device remains unchanged after compressing the data.

11. The method of claim 1 further comprising monitoring I/O transactions from the host device to determine if a rule is violated by utilizing the free memory space resulting from compressing the data.

12. A storage device comprising:

an interface through which to communicate with a host device;

a non-volatile memory; and

a controller in communication with the interface and the non-volatile memory, the controller configured to;

determine whether data stored in a storage area in the memory is suitable for compression;

if the data is suitable for compression, compress the data; and

use free memory space resulting from compressing the data for an internal storage device operation.

13. The storage device of claim 12, wherein determining whether data is suitable for compression comprises determining whether the data is backup data.

14. The storage device of claim 12, wherein determining whether data is suitable for compression comprises determining a compression efficiency for the data.

15. The storage device of claim 12, wherein determining whether data is suitable for compression comprises determining an access frequency of the data.

16. The storage device of claim 12, wherein the controller is further operative to determine a compression algorithm to use to compress the data.

17. The storage device of claim 12, wherein the controller is further operative to determine a schedule for compressing the data.

18. The storage device of claim 12, wherein the controller is further operative to compress the data would violate a rule.

19. The storage device of claim 18, wherein the rule is violated if a logical partition is reformatted.

20. The storage device of claim 18, wherein the rule is violated if a change is made to data that is frequently accessed or modified.

21. The storage device of claim 12, wherein a total exported capacity reported to the host device remains unchanged after compressing the data.

22. The storage device of claim 12, wherein the controller is further configured to monitor I/O transactions from the host device to determine if a rule is violated by utilizing the free memory space resulting from compressing the data.