Method and apparatus for restricting writes to solid state memory when an end-of life condition is reached

Patent metadata

Field	Value
Publication number	US-9268487-B2
Application number	US-201414275032-A
Country	US
Kind code	B2
Filing date	May 12, 2014
Priority date	Mar 24, 2014
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

A data storage device including a solid state memory comprising logical block addresses (“LBAs”) corresponding to boot data accessed by a host during a boot process, and a controller. The controller can be configured to determine the LBAs corresponding to the boot data, and determine whether the solid state memory has reached an end-of-life condition. Upon determining that solid state memory has reached an end-of-life condition, the controller can restrict the host to write to the LBAs corresponding to the boot data during a boot process, and set the solid state memory into a read only mode when the boot process is complete.

First claim

What is claimed is:

1. A data storage device comprising:
a solid state memory comprising logical block addresses (“LBAs”) corresponding to boot data accessed by a host during a boot process; and
a controller configured to:
determine the LBAs corresponding to the boot data;
determine whether the solid state memory has reached an end-of-life condition;
upon determining that solid state memory has reached an end-of-life condition:
restrict the host to write to the LBAs corresponding to the boot data during a boot process, and
set the solid state memory into a read only mode when the boot process is complete.

2. The data storage device of claim 1 wherein an end-of-life condition is reached when a number of write erase cycles for the solid state memory is within a predetermined number of write erase cycles from an end-of-life number of write erase cycles for the solid state memory.

3. The data storage device of claim 2 wherein the controller is further configured to set the solid state memory into the read only mode when the number of write erase cycles is equal to or greater than the end-of-life number of write erase cycles for the solid state memory.

4. The data storage device of claim 1 wherein an end-of-life condition is reached when a spare block count for the solid state memory is less than a predetermined threshold of spare block counts.

5. The data storage device of claim 1 wherein the controller is further configured to:
limit a number of writes to a reserved area in the solid state memory prior to determining that the solid state memory has reached an end-of-life condition; and
use the reserved area for handling the host writes to the LBAs corresponding to the boot data upon determination that solid state memory has reached an end-of-life condition.

6. The data storage device of claim 1 wherein the controller is further configured to restrict the host writes by:
learning a pattern of LBAs accessed by the host during the boot process; and
limiting the host writes to those LBAs in the pattern of LBAs accessed by the host during the boot process.

7. The data storage device of claim 1 wherein the controller is further configured to restrict the host writes by:
limiting the host to a predetermined number of writes.

8. The data storage device of claim 7 wherein the predetermined number of writes is a preset number of writes.

9. The data storage device of claim 7 wherein the predetermined number of writes is learned by observing a number of writes performed by the host during the boot process.

10. The data storage device of claim 1 further comprising a magnetic rotating disk.

11. A method for operating a data storage device comprising:
determining logical block addresses (“LBAs”) corresponding to boot data access by a host during a boot process, wherein the LBAs comprise LBAs of a solid state memory of the data storage device;
determining whether the solid state memory has reached an end-of-life condition; and
upon determining that the solid state memory has reached an end-of-life condition:
restricting the host to write to the LBAs corresponding to the boot data during a boot process, and
setting the solid state memory into a read only mode when the boot process is complete.

12. The method of claim 11 wherein an end-of-life condition is reached when a number of write erase cycles for the solid state memory is within a predetermined number of write erase cycles from an end-of-life number of write erase cycles for the solid state memory.

13. The method of claim 12 further comprising setting the solid state memory into the read only mode when the number of write erase cycles is equal to or greater than the end-of-life number of write erase cycles for the solid state memory.

14. The method of claim 11 wherein an end-of-life condition is reached when a spare block count for the solid state memory is less than a predetermined threshold of spare block counts.

15. The method of claim 11 further comprising:
limiting a number of writes to a reserved area in the solid state memory prior to determining that the solid state memory has reached an end-of-life condition; and
using the reserved area for handling the host writes to the LBAs corresponding to the boot data upon determination that the solid state memory has reached an end-of-life condition.

16. The method of claim 11 wherein the restricting the host writes further comprises:
learning a pattern of LBAs accessed by the host during the boot process; and
limiting the host writes to those LBAs in the pattern of LBAs accessed by the host during the boot process.

17. The method of claim 11 wherein the restricting the host writes further comprises:
limiting the host to a predetermined number of writes.

18. The method of claim 17 wherein the predetermined number of writes is a preset number of writes.

19. The method of claim 17 wherein the predetermined number of writes is learned by observing a number of writes performed by the host during the boot process.

20. The method of claim 11 wherein the data storage device further comprises a magnetic rotating disk.

21. An electronic device comprising:
a host processor configured to write boot data during a boot process; and
a data storage device comprising:
a solid state memory comprising logical block addresses (“LBAs”) corresponding to the boot data accessed by the host processor during the boot process; and
a controller configured to:
determine the LBAs corresponding to the boot data from the host processor;
determine whether the solid state memory has reached an end-of-life condition;
upon determining that the solid state memory has reached an end-of-life condition:
restrict the host processor to write to the LBAs corresponding to the boot data during a boot process, and
set the solid state memory into a read only mode when the boot process is complete.

22. The electronic device of claim 21 wherein an end-of-life condition is reached when a number of write erase cycles for the solid state memory is within a predetermined number of write erase cycles from an end-of-life number of write erase cycles for the solid state memory.

23. The electronic device of claim 22 wherein the controller is further configured to set the solid state memory into the read only mode when the number of write erase cycles is equal to or greater than the end-of-life number of write erase cycles for the solid state memory.

24. The electronic device of claim 21 wherein an end-of-life condition is reached when a spare block count for the solid state memory is less than a predetermined threshold of spare block counts.

25. The electronic device of claim 21 wherein the controller is further configured to:
limit a number of writes to a reserved area in the solid state memory prior to determining that the solid state memory has reached an end-of-life condition; and
use the reserved area for handling the writes from the host processor to the LBAs corresponding to the boot data upon determination that the solid state memory has reached an end-of-life condition.

26. The electronic device of claim 21 wherein the controller is further configured to restrict the writes from the host processor by:
learning a pattern of LBAs accessed by the host processor during the boot process; and
limiting the writes by the host processor to those LBAs in the pattern of LBAs accessed by

Assignees

• Western Digital Tech Inc

Inventors

• Gibbons Kent W
• Morgan Colin W

Classifications

• G06F12/0246

  in block erasable memory, e.g. flash memory · CPC title

• G06F3/0619

  in relation to data integrity, e.g. data losses, bit errors · CPC title

• G06F9/4401

  Bootstrapping (security arrangements therefor G06F21/57) · CPC title

• G06F3/0632

  by initialisation or re-initialisation of storage systems · CPC title

• G06F3/0637

  Permissions · CPC title