Track allocation method of disk drive

• US 20070183071A1
• Filed: 12/21/2006
• Published: 08/09/2007
• Est. Priority Date: 01/04/2006
• Status: Active Grant

• Current Assignee: HGST Netherlands B.V. (Western Digital Corporation)
• Original Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Inventors: Saga, Hideki, Uemura, Tetsuya
• Granted Patent: US 7,408,731 B2
• Time in Patent Office: Days
• US Class Current: 360/48
• CPC Class Codes: G11B 20/1258 where blocks are arranged within multiple radial zones, e.g. Zone Bit Recording or Constant Density Recording discs, MCAV discs, MCLV discs
• CPC Class Codes: G11B 20/1883 Methods for assignment of alternate areas for defective areas
• CPC Class Codes: G11B 2020/1238 track, i.e. the entire a spirally or concentrically arranged path on which the recording marks are located
• CPC Class Codes: G11B 2020/1242 the area forming one or more zones, wherein each zone is shaped like an annulus or a circular sector
• CPC Class Codes: G11B 2020/1289 Formatting of user data
• CPC Class Codes: G11B 2020/1292 Enhancement of the total storage capacity
• CPC Class Codes: G11B 2220/20 Disc-shaped record carriers
• CPC Class Codes: G11B 2220/2516 Hard disks
• CPC Class Codes: G11B 5/09 Digital recording

Abstract

Embodiments in accordance with the present invention relate to methods wherein a capacity of a disk drive is increased by partially overwriting adjacent tracks to shorten the track width and collectively updating a data update unit made up of a plurality of tracks, wherein the capacity reduction caused by a defective track is suppressed. Track groups having two types of track widths, or Shingled Tracks(ST) and Tiled Tracks(TT), are allocated in a zone. First, the zone is divided into two areas, namely, a shingled track (ST) area and a spare or tiled track (TT) area. When a defective track is detected in the shingled track (ST) area, it is checked whether or not the spare or tiled track (TT) area affords an area to be transferred. If it does, an area is transferred from the spare or tiled track (TT) area to the shingled track (ST) area. When it is confirmed that the allocation of ST has been completed, TT is allocated to the remaining spare or tiled track (TT) area in subsequent steps.

Claims

1. A track allocation method of a disk drive, the disk drive comprising:

a storage medium and a controller sending and receiving commands and data to and from a high-order device and performing writing control or reading control over said storage medium;

wherein said storage medium is divided into a plurality of zones having different numbers of sectors for each track;

wherein there exist a first track group having a first track width and a second track group having a second track width on said storage medium; and

wherein, when areas of said first track group and said second track group are secured in said zone, said controller executes the steps of;

dividing said zone into a first area for said first track group and a second area for said second track group based on a capacity ratio of said first track group to said second track group to be secured in said zone or based on a first initial value of the capacity of said first track group and a second initial value of the capacity of said second track group;

allocating said first track group to said first area;

transferring an area lacking because of a defective track from said second area to said first area when there exists the defective track causing prohibition of use of the entire track in said first area; and

allocating said second track group to said second area.

2. A track allocation method of a disk drive according to claim 1, wherein said controller executes the step of setting said capacity ratio or said first initial value and said second initial value based on one value or a plurality of values specified by the high-order device.

3. A track allocation method of a disk drive according to claim 1, wherein said controller executes the step of storing, in a system area of said disk drive referable from the high-order device,

said capacity ratio or said first initial value and said second initial value;

and

a ratio of the capacity of said first track group allocated to said first area to the capacity of said second track group allocated to said second area or the capacity of said first track group allocated to said first area and the capacity of said second track group allocated to said second area.

4. A track allocation method of a disk drive according to claim 1, wherein said controller executes the steps of:

calculating a capacity of said second track group that can be allocated to said second area; and

halting, when said calculated capacity is less than the prescribed minimum capacity, the execution of the step of transferring tracks lacking because of said defective tracks from said second area to said first area.

5. A track allocation method of a disk drive according to claim 4, wherein said controller executes the step of setting said minimum capacity based on a value specified by a high-order device.

6. A track allocation method of a disk drive, the disk drive comprising a storage medium and a controller sending and receiving commands and data to and from a high-order device and performing writing control or reading control over said storage medium;

wherein said storage medium is divided into a plurality of zones having different numbers of sectors for each track;

wherein there exist a first track group having a first track width and a second track group having a second track width on said storage medium;

wherein said first track group is divided into groups each having prescribed first numbers of tracks; and

wherein, when areas of said first track group and said second track group are secured in said zone, said controller executes the steps of;

dividing said zone into a first area for said first track group and a second area for said second track group based on a capacity ratio of said first track group to said second track group to be secured in said zone or based on a first initial value of the capacity of said first track group and a second initial value of the capacity of said second track group;

allocating said first track group to said first area;

allocating said second track group with said second numbers of tracks to an area in the vicinity of a defective track where the first track group with numbers of tracks cannot be secured when there exists the defective track causing prohibition of use of the entire tracks in said first area and transferring an area corresponding to said second numbers of tracks from said second area to said first area; and

allocating said second track group to said second area.

7. A track allocation method of a disk drive according to claim 6, wherein said controller executes the step of setting said first number of tracks based on a value specified by a high-order device.

8. A track allocation method of a disk drive according to claim 6, wherein an area corresponding to said defective tracks is also transferred from said second area to said first area when an area corresponding to said second numbers of tracks is transferred from said second area to said first area.