Method for efficient write operations on a data carrier with overlapping data tracks and device thereof

• US 9,129,652 B1
• Filed: 03/02/2015
• Issued: 09/08/2015
• Est. Priority Date: 03/04/2014
• Status: Active Grant

• Current Assignee: Inodyn Newmedia GmbH
• Original Assignee: Inodyn Newmedia GmbH
• Inventors: Pantel, Lothar
• Primary Examiner(s): Hindi, Nabil
• Application Number:
  US14/635,965
• Publication Number:
  US 20150255115A1
• Time in Patent Office: 190 Days
• Field of Search: 360/78.04, 360/60, 360/48, 360/49, 360/78.14, 711/712
• US Class Current: 1/1
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 12/10 Address translation
• CPC Class Codes: G06F 2212/1032 Reliability improvement, data loss prevention, degraded operation etc
• CPC Class Codes: G06F 2212/152 Virtualized environment, e.g. logically partitioned system
• CPC Class Codes: G06F 2212/21 Employing a record carrier using a specific recording technology
• CPC Class Codes: G06F 2212/657 Virtual address space management
• CPC Class Codes: G06F 2212/70 Details relating to dynamic memory management
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0673 Single storage device
• CPC Class Codes: G06F 3/0676 Magnetic disk device
• CPC Class Codes: G11B 20/1217 on discs
• CPC Class Codes: G11B 20/1252 for discontinuous data, e.g. digital information signals, computer programme data
• CPC Class Codes: G11B 2020/1238 track, i.e. the entire a spirally or concentrically arranged path on which the recording marks are located

Abstract

A method and a device for efficient write operations are disclosed, which may be used in connection with shingled magnetic recording (SMR) in order to reduce write amplification (read-modify-write). The tracks on at least one data carrier surface are grouped into bands, and the address space of logical block addresses is divided into address subsets. Each of these address subsets is permanently assigned to a dedicated selection of tracks derived from all bands. Depending on the embodiment, the dedicated selection of tracks may be chosen in such a way that no write amplification occurs in a first phase and/or that recent data or newly added data can be altered without necessitating read-modify-write.

Claims

1. A method for storing data on at least one data carrier surface of a storage device configured for overlapping data tracks, comprising:

a) establishing a substantially immutable relation between a plurality of logical block addresses and physical locations on a plurality of tracks, said tracks being grouped into a plurality of bands,

b) dividing the address space of said logical block addresses into at least two address subsets,

c) assigning each address subset permanently to a dedicated selection of tracks of each band, said dedicated selection of tracks comprising substantially at least one track per band and encompassing all bands of said plurality of bands.

2. The method of claim 1, wherein an address subset is permanently assigned to a dedicated selection of tracks that are far enough apart so that, when overwriting a track from said dedicated selection, none of the other tracks from said dedicated selection are deleted by the data track of a write element with an excess width.

3. The method of claim 1, wherein an address subset is permanently assigned to a dedicated selection of tracks comprising substantially all tracks adjacent to guard regions, such that the excess width of a write element is caught by said guard regions.

4. The method of claim 1, further comprising at least one band whose associated guard region is located in the middle or near the middle of said band, both tracks adjacent to said guard region being written such that the excess width of a write element is caught by said guard region from both sides.

5. The method of claim 4, wherein overlapping data tracks, written by said write element, converge from both outer boundaries of said band inward, toward said guard region, establishing overlaps in opposite radial directions within said band.

6. The method of claim 5, further comprising:

a) assigning a first address subset permanently to a dedicated selection of tracks comprising the two outermost tracks on both sides of each band,

b) assigning a second address subset permanently to a dedicated selection of tracks comprising the next inwardly adjacent tracks on both sides of each band,

c) writing data to substantially all tracks of said first address subset, essentially in a first phase,

d) writing data to substantially all tracks of said second address subset, essentially in a second phase.

7. The method of claim 1, further comprising at least two adjacent bands whose shared guard region is located at the common boundary of said bands, the tracks adjacent to said common boundary being written such that the excess width of a write element is caught by said shared guard region from both sides.

8. The method of claim 7, wherein overlapping data tracks, written by said write element, diverge from a location in the middle or near the middle of each band outward, toward said shared guard regions, establishing overlaps in opposite radial directions within said bands.

9. The method of claim 8, further comprising:

a) assigning a first address subset permanently to a dedicated selection of tracks comprising two adjacent tracks from said location in the middle or near the middle of each band,

b) assigning a second address subset permanently to a dedicated selection of tracks comprising the next outwardly adjacent tracks on both sides of each band,

c) writing data to substantially all tracks of said first address subset, essentially in a first phase,

d) writing data to substantially all tracks of said second address subset, essentially in a second phase.

10. The method of claim 1, further comprising:

a) assigning a first address subset permanently to a dedicated selection of tracks comprising the first track of each band,

b) assigning a second address subset permanently to a dedicated selection of tracks comprising the second track of each band,

c) writing data to substantially all tracks of said first address subset, essentially in a first phase,

d) writing data to substantially all tracks of said second address subset, essentially in a second phase.

11. The method of claim 1, further comprising a plurality of data carrier surfaces, wherein a first address subset is permanently assigned to a dedicated selection of tracks encompassing tracks from each data carrier surface of said plurality of data carrier surfaces, said storage device being filled with data, wherein essentially in a first phase data are written to all data carrier surfaces by means of said first address subset, and wherein data are written to remaining empty tracks on all data carrier surfaces essentially in at least one subsequent phase.

12. The method of claim 1, further comprising an optimized address subset whose range of logical block addresses encompass substantially all logical block addresses of a file management table, directory, or region for index data, said optimized address subset being permanently assigned to a dedicated selection of tracks comprising tracks adjacent to guard regions, such that the excess width of a write element is caught by said guard regions.

13. The method of claim 1, wherein:

a) said storage device is a hard disk drive that operates according to the shingled magnetic recording methodology,

b) said data carrier surface is a disk surface of said hard disk drive,

c) said overlapping data tracks are grouped into bands and are separated by guard regions in accordance with the shingled magnetic recording methodology,

d) said physical locations on said tracks are physical sectors.

14. A storage device configured for overlapping data tracks, comprising:

a) at least one data carrier surface,

b) a plurality of tracks at least on said data carrier surface, said plurality of tracks being grouped into a plurality of bands,

c) at least one write element whose data track width exceeds the track width of a read element by an excess width,

d) a control unit configured to establish a substantially immutable relation between a plurality of logical block addresses and physical locations on said plurality of tracks, wherein the address space of said logical block addresses is divided into at least two address subsets, and wherein each address subset is permanently assigned to a dedicated selection of tracks of each band, said dedicated selection of tracks comprising substantially at least one track per band and encompassing all bands of said plurality of bands.

15. The storage device of claim 14, wherein an address subset is permanently assigned to a dedicated selection of tracks that are far enough apart so that, when overwriting a track from said dedicated selection, none of the other tracks from said dedicated selection are deleted by said excess width of said write element.

16. The storage device of claim 14, wherein an address subset is permanently assigned to a dedicated selection of tracks comprising substantially all tracks adjacent to guard regions, such that said excess width of said write element is caught by said guard regions.

17. The storage device of claim 14, further comprising at least one band whose associated guard region is located in the middle or near the middle of said band, both tracks adjacent to said guard region being written such that said excess width of said write element is caught by said guard region from both sides.

18. The storage device of claim 14, further comprising at least two adjacent bands whose shared guard region is located at the common boundary of said bands, the tracks adjacent to said common boundary being written such that said excess width of said write element is caught by said shared guard region from both sides.

19. The storage device of claim 14, wherein each band comprises overlapping data tracks with overlaps in opposite radial directions between the middle or near the middle of each band and the band boundaries.

20. The storage device of claim 14, further comprising a plurality of data carrier surfaces, wherein a first address subset is permanently assigned to a dedicated selection of tracks encompassing tracks from each data carrier surface of said plurality of data carrier surfaces.

21. A hard disk controller configured for overlapping data tracks, comprising control circuitry operable to establish a substantially immutable relation between a plurality of logical block addresses and physical locations on a plurality of tracks, said tracks being grouped into a plurality of bands, wherein the address space of said logical block addresses is divided into at least two address subsets, and wherein each address subset is permanently assigned to a dedicated selection of tracks of each band, said dedicated selection of tracks comprising substantially at least one track per band and encompassing all bands of said plurality of bands.