Dynamically assigning inactive pages not used in Reed-Solomon code in non-volatile solid-state storage array
View Patent ↗A data storage device is disclosed comprising non-volatile solid-state array comprising M storage elements for storing data protected by Reed-Solomon (R-S) code, each storage element comprising multiple blocks, each block comprising multiple pages for storing data. The data storage device further comprises a controller in communication with the storage array and defining a superblock comprising logical grouping of M blocks, each located in different storage element, and multiple superpages in each superblock, each superpage comprising M pages, each located in a different storage element. The controller generates, for each superpage, at least one R-S code parity page for protecting data pages in the superpage, where number of data pages and the at least one parity page is equal to M−1. The controller assigns one page in each superpage as an inactive page not used in the R-S code, where at least two inactive pages are in different storage elements.
1. A data storage device comprising:
a non-volatile solid-state storage array comprising M storage elements for storing data protected by a Reed-Solomon code, each storage element comprising a plurality of blocks, and each block comprising a plurality of pages for storing data;
a controller in communication with the non-volatile solid-state storage array and operable to:
define a superblock comprising a logical grouping of M blocks, wherein each block in the superblock is located in a different storage element, wherein each superblock comprises a plurality of superpages, wherein each superpage comprises a logical grouping of M pages, and wherein each page in a superpage is in a different storage element;
generate, for each superpage, at least one Reed-Solomon code parity page protecting data pages in the superpage, wherein the number of data pages and the at least one parity page is equal to M−1; and
assign one page in each superpage as an inactive page not used in the Reed-Solomon code, wherein at least two of the inactive pages are in different storage elements.
2. The data storage device as recited in claim 1 , wherein the controller is further operable to move the inactive page in at least one superpage from a first location in a first storage element to a second location in a second storage element.
3. The data storage device as recited in claim 2 , wherein the controller is operable to move the inactive page in at least one superpage during a wear leveling operation.
4. The data storage device as recited in claim 2 , wherein the controller is operable to move the inactive page in at least one superpage during a garbage collection operation.
5. The data storage device as recited in claim 2 , wherein the controller is operable to move the inactive page in at least one superpage during an error handling operation.
6. The data storage device as recited in claim 1 , wherein the controller is further operable to track the location of the inactive page in each superpage.
7. The data storage device as recited in claim 6 , wherein the controller is operable to track the location of the inactive page in each superpage by using a tracking table.
8. The data storage device as recited in claim 1 , wherein the controller is operable to assign a defective page in a superpage as the inactive page.
9. The data storage device as recited in claim 1 , wherein the controller is operable to assign a page having a quality level below a threshold in a superpage as the inactive page.
10. The data storage device as recited in claim 1 , wherein at least two inactive pages in at least two superpages in a superblock are in different storage elements.
11. The data storage device as recited in claim 1 , wherein all of the inactive pages in all of the superpages in a superblock are in the same storage element.
12. The data storage device as recited in claim 1 , wherein the storage element comprises a die.
13. The data storage device as recited in claim 1 , wherein the storage element comprises a plane, and wherein at least two planes are located in one die.
14. The data storage device as recited in claim 1 , wherein M is equal to 256.
15. The data storage device as recited in claim 1 , wherein the Reed-Solomon code comprises 8-bit symbols.
16. The data storage device as recited in claim 1 , further comprising magnetic media for storing data.
17. The data storage device as recited in claim 1 , wherein the inactive page is assigned in each and every superpage within the super block.
18. The data storage device as recited in claim 1 , wherein the inactive page is dynamically assigned to each superpage regardless of whether a defect occurs in the superpage.
19. A method of operating a data storage device, the data storage device comprising a non-volatile storage array comprising M storage elements for storing data protected by a Reed-Solomon code, each storage element comprising a plurality of blocks, and each block comprising a plurality of pages for storing data, the method comprising:
defining a superblock comprising a logical grouping of M blocks, wherein each block in the superblock is located in a different storage element, wherein each superblock comprises a logical grouping of M pages, and wherein each page in a superpage is in a different storage element;
generating, for each superpage, at least one Reed-Solomon code parity page protecting data pages in the superpage, wherein the number of data pages and the at least one parity page is equal to M−1; and
assigning one page in each superpage as an inactive page not used in the Reed-Solomon code, wherein at least two of the inactive pages are in different storage elements.
20. The method as recited in claim 19 , further comprising moving the inactive page in at least one superpage from a first location in a first storage element to a second location in a second storage element.
21. The method as recited in claim 20 , wherein the inactive page in at least one superpage is moved during a wear leveling operation.
22. The method as recited in claim 20 , wherein the inactive page in at least one superpage is moved during a garbage collection operation.
23. The method as recited in claim 20 , wherein the inactive page in at least one superpage is moved during an error handling operation.
24. The method as recited in claim 19 , further comprising tracking the location of the inactive page in each superpage.
25. The method as recited in claim 24 , wherein tracking the location of the inactive page in each superpage comprises using a tracking table.
26. The method as recited in claim 19 , further comprising assigning a defective page in a superpage as the inactive page.
27. The method as recited in claim 19 , further comprising assigning a page having a quality level below a threshold in a superpage as the inactive page.
28. The method as recited in claim 19 , wherein at least two inactive pages in at least two superpages in a superblock are in different storage elements.
29. The method as recited in claim 19 , wherein all of the inactive pages in all of the superpages in a superblock are in the same storage element.
30. The method as recited in claim 19 , wherein the storage element comprises a die.
31. The method as recited in claim 19 , wherein the storage element comprises a plane, and wherein at least two planes are located in one die.
32. The method as recited in claim 19 , wherein M is equal to 256.
33. The method as recited in claim 19 , wherein the Reed-Solomon code comprises 8-bit symbols.
34. The method as recited in claim 19 , wherein the data storage device further comprises magnetic media for storage data.