System, method and a computer program product for writing data to different storage devices based on write frequency

• US 7,849,275 B2
• Filed: 11/19/2007
• Issued: 12/07/2010
• Est. Priority Date: 11/19/2007
• Status: Expired due to Fees

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: SandForce, Inc. (Broadcom, Inc.)
• Inventors: Danilak, Radoslav
• Primary Examiner(s): Nguyen; Hiep T
• Application Number:
  US11/942,640
• Publication Number:
  US 20090132778A1
• Time in Patent Office: 1,114 Days
• Field of Search: None
• US Class Current: 711/154
• CPC Class Codes: G06F 11/008 Reliability or availability analysis
• CPC Class Codes: G11C 16/349 Arrangements for evaluating degradation, retention or wearout, e.g. by counting erase cycles
• CPC Class Codes: G11C 2211/5641 Multilevel memory having cells with different number of storage levels

Abstract

A system, method, and computer program product are provided for writing data to different storage devices based on write frequency. In operation, a frequency in which data is written is identified. Additionally, a plurality of storage devices of different types is selected from to write the data, based on the frequency.

Claims

1. A method, comprising:

monitoring frequency values at which data is written into portions of a memory comprising a plurality of storage technologies, each portion comprising a particular storage technology of the plurality of storage technologies and having a respective lifetime; and

dynamically selecting the portions in which the data is written, based at least in part on the monitored frequency values and the respective lifetimes of the portions.

2. The method of claim 1, wherein the dynamically selecting is further based at least in part on a threshold.

3. The method of claim 1, further comprising determining a threshold.

4. The method of claim 3, wherein the data is written to a second portion of the portions if the frequency of the data written to a first portion of the portions exceeds the threshold.

5. The method of claim 4, wherein the first portion comprises a single-level cell (SLC) storage technology of the storage technologies.

6. The method of claim 3, wherein the data is written to a second portion of the portions if the frequency of the data written to a first portion of the portions does not exceed the threshold.

7. The method of claim 4, wherein the first portion comprises a multi-level cell (MLC) storage technology of the storage technologies.

8. The method of claim 1, wherein the frequency values are monitored by a lifetime estimator module.

9. The method of claim 8, wherein the portions correspond to storage devices and the lifetime estimator module computes an estimated lifetime of the storage devices.

10. The method of claim 8, wherein the portions correspond to storage devices and the lifetime estimator module computes an estimated lifetime of the storage devices, based on storage commands.

11. The method of claim 1, wherein the plurality of storage technologies comprises a mechanical storage technology.

12. The method of claim 11, wherein the mechanical storage technology includes a disk drive.

13. The method of claim 1, wherein the plurality of storage technologies comprises a solid state storage technology.

14. The method of claim 13, wherein the solid state storage technology comprises flash memory technology.

15. The method of claim 14, wherein the flash memory technology includes NAND flash memory.

16. The method of claim 1, wherein the plurality of storage technologies comprises single-level cell (SLC) flash memory storage technology and multi-level cell (MLC) flash memory storage technology, and the SLC flash memory and the MLC flash memory storage technologies are integrated in one device.

17. The method of claim 16, and further comprising programmatically determining the particular storage technology of at least one of the portions.

18. The method of claim 1, wherein the plurality of storage technologies comprises two different types of single-level cell (SLC) flash memory storage technology, and the two different types of SLC flash memory storage technology are integrated in one device.

19. The method of claim 1, wherein the plurality of storage technologies comprises volatile memory.

20. The method of claim 1, wherein the plurality of storage technologies comprises non-volatile memory.

21. The method of claim 1, wherein an order in which the portions are written and recycled is dynamically managed to equalize respective life expectancies of the portions in view of differences in endurance values of the portions.

22. The method of claim 1, wherein the respective lifetime of a particular one of the portions is based at least in part on a length of time to perform an erase operation on at least a part of the particular one of the portions.

23. The method of claim 1, wherein the respective lifetime of a particular one of the portions is based at least in part on a length of time to perform a program operation on at least a part of the particular one of the portions.

24. The method of claim 1, wherein the respective lifetime of a particular one of the portions is based at least in part on a number of corrected errors with respect to at least a part of the particular one of the portions.

25. The method of claim 1, wherein the respective lifetime of a particular one of the portions is based at least in part on a number of intervening reads with respect to at least a part of the particular one of the portions.

26. The method of claim 1, wherein the portions comprise a first portion comprising single-level cell (SLC) storage technology and a second portion comprising multi-level cell (MLC) storage technology and the dynamically selecting is enabled to select the first portion when the frequency of the data written is at least a particular rate and the dynamically selecting is enabled to otherwise select the second portion.

27. The method of claim 1, wherein the portions comprise a first portion comprising multi-level cell (MLC) storage technology of a first endurance and a second portion comprising MLC storage technology of a second endurance.

28. The method of claim 1, wherein the portions comprise a first portion comprising a storage technology with a first lifetime and a second portion comprising a storage technology with a second lifetime.

29. The method of claim 28, wherein the dynamically selecting is based at least in part on a difference in life expectancy of at least some of the portions.

30. The method of claim 28, wherein the frequency value of the first portion is a high frequency and the frequency value of the second portion is a low frequency.

31. The method of claim 30, wherein the first portion comprises a single-level cell (SLC) storage technology and the second portion comprises a multi-level cell (MLC) storage technology.

32. The method of claim 31, wherein the SLC and the MLC storage technologies are integrated in one device.

33. The method of claim 1, wherein the plurality of storage technologies of the memory are comprised within a first level of memory organization.

34. The method of claim 1, wherein each portion comprises at least one memory block.

35. The method of claim 1, wherein each portion comprises at least one memory module.

36. The method of claim 1, wherein each portion comprises at least one storage device.

37. A non-transitory computer readable medium having a set of instructions stored therein which when executed by a processor causes the processor to perform functions, comprising:

monitoring frequency values at which data is written into portions of a memory comprising a plurality of storage technologies, each portion comprising a particular storage technology of the plurality of storage technologies and having a respective lifetime; and

dynamically selecting the portions in which the data is written, based at least in part on the monitored frequency values and the respective lifetimes of the portions.

38. An apparatus, comprising:

means for monitoring frequency values at which data is written into portions of a memory comprising a plurality of storage technologies, each portion comprising a particular storage technology of the plurality of storage technologies and having a respective lifetime; and

means for dynamically selecting the portions in which the data is written, based at least in part on the monitored frequency values and the respective lifetimes of the portions.

39. The apparatus of claim 38, wherein at least the means for monitoring is coupled between a system and the memory.