DEFECT MANAGEMENT USING MUTABLE LOGICAL TO PHYSICAL ASSOCIATION

• US 20090055620A1
• Filed: 08/21/2007
• Published: 02/26/2009
• Est. Priority Date: 08/21/2007
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Miller, Craig W., Haines, Jonathan W., Feldman, Timothy R., Olds, Edwin S.
• Granted Patent: US 7,827,378 B2
• Time in Patent Office: Days
• US Class Current: 711/202
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/1032 Reliability improvement, data loss prevention, degraded operation etc
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence

Abstract

The application relates to defect management using mutable logical to physical association. Embodiments disclosed utilize mutable mapping between logical blocks and physical blocks. Dynamically updated mapping data, which mutably associates the logical blocks and the physical blocks, also includes physical block defect allocations.

Claims

1. A method comprising:

assigning a set of logical block addresses (LBAs) from a logical space to physical block addresses (PBAs) in a physical space;

in conjunction with a transfer of data to physical blocks at individual PBAs in the physical space, newly associating individual LBAs of the set of LBAs to the individual PBAs in the physical space; and

upon detecting a defect in a physical block at an individual PBA in the physical space, designating the defective physical block as not safe to use.

2. The method of claim 1 and further comprising maintaining map data which identifies, for each of the PBAs, whether the PBA is currently available for association with a LBA from the set of LBAs.

3. The method of claim 2 wherein designating the defective physical block as not safe to use comprises updating the map data to indicate that the individual PBA of the defective physical block is permanently unavailable for association with any individual LBA of the set of LBAs.

4. The method of claim 2 wherein the physical storage space comprises a storage medium, and wherein the map data is stored on the storage medium.

5. The method of claim 1 wherein the defect in the physical block is a grown defect.

6. The method of claim 1 wherein the defect in the physical block is a factory-time defect.

8. The method of claim 1 wherein assigning a set of LBAs from a logical space to PBAs in a physical space comprises assigning a set of LBAs from a logical space to a band of PBAs in a physical space.

9. The method of claim 8 wherein designating the defective physical block as not safe to use comprises updating map data to indicate that the individual PBA of the defective physical block is permanently unavailable for association with any individual LBA of the set of LBAs currently assigned to the band.

10. The method of claim 8 wherein the physical space comprises a storage medium, and wherein the band comprises a plurality of tracks on the storage medium.

11. The method of claim 10 wherein the plurality of tracks are characterized as overlapping tracks.

12. The method of claim 8 wherein the physical space comprises a storage medium, and wherein the band comprises flash memory pages on the storage medium.

13. The method of claim 12 wherein the flash memory pages are characterized as pages that physically have inter-symbol interference.

15. The map of claim 9 wherein the dynamically updated map is stored on a computer-readable storage medium.

16. The map of claim 9 wherein the dynamically updated map utilizes similar status codes for grown defects and factory-time defects.

14. A map comprising:

a dynamically updated map that mutably associates logical blocks to physical blocks,

wherein the dynamically updated map further comprises physical block defect allocations.

17. A method comprising:

upon detecting a grown defect in a first physical block on a storage medium, mapping out the first physical block from a logical-to-physical mapping of the storage medium,

wherein the logical-to-physical mapping for the storage medium is independent of any reserved spare sectors; and

storing data to the storage medium according to the logical-to-physical mapping of the storage medium.

18. The method of claim 17 and further comprising:

upon detecting a factory-time defect in a second physical sector of a storage medium, mapping out the second physical sector from a logical-to-physical mapping of the storage medium.

19. The method of claim 18 and further comprising:

utilizing similar defect identification codes to represent the grown defect and the factory-time defect, thereby enabling use of a same mapping out process for the first physical block and the second physical block.

20. The method of claim 17 and further comprising, for physical blocks on the storage medium, establishing a substantially one-to-one correspondence between PBAs and LBAs during manufacture of a device that includes the storage medium.

21. A method comprising:

installing a storage medium having a plurality of physical blocks in a storage device;

completing manufacture of the storage device; and

certifying at least some of the plurality of physical blocks subsequent to manufacture of the storage device to identify defective physical blocks.

22. The method of claim 21 and further comprising maintaining map data which identifies defective physical blocks.

23. The method of claim 22 wherein the map data further comprises information about LBAs associated with PBAs corresponding to the plurality of physical blocks.

24. The method of claim 21 wherein the storage medium comprises a plurality of tracks that include the plurality of physical blocks.

25. The method of claim 21 wherein the storage medium comprises a plurality of flash memory pages that include the plurality of physical blocks.