System and method for correcting for head tilt in HDD
AssigneeHitachi Global Storage Technologies Netherlands B.V.
InventorsDaniel Jonathan Auerbach, Jeffrey Joesph Dobbek, Gregory Michael Frees, David Robison Hall
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Abstract
Tilt between a head stack and its associated disk stack in a hard disk drive (HDD) is measured by determining the deviation of a target head from its expected position (based on the position of the current head) each time electrical contact is switched from the current head to a target head. A running average tilt value is stored and used to modify the logical seek distance used in a Rotational Position Optimization (RPO) algorithm to better order I/O requests in a queue. Also, the running average tilt value can be used by the servo to pre-position the target head before electrical contact is made with the target head, to improve speed of operation.
Claims17
A method for controlling a disk drive having a disk stack and a head stack, comprising:
- ordering requests in a queue of the disk drive based at least in part on a mechanical tilt between the disk stack and head stack.
A method for controlling a disk drive having a disk stack and a head stack, comprising:
- moving a target head toward a position on a disk before electrical contact is made with the target head at least in part based on a mechanical tilt between the disk stack and head stack.
A method for accounting for mechanical tilt between a head stack and a disk stack in a hard disk drive (HDD) including a HDD controller, comprising:
- moving a target head toward a position on a disk before electrical contact is made with the target head at least in part based on a mechanical tilt between the disk stack and head stack;
- and
- ordering requests in a queue of the HDD based at least in part on the mechanical tilt.
Dependencies are inferred from the claim text.