US 12,633,306 B1Granted

Magnetic disk device and method

AssigneesKabushiki Kaisha Toshiba, Toshiba Electronic Devices & Storage Corporation

InventorsSho Suzuki, Takeyori Hara

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Abstract

According to the embodiment, a controller of a magnetic disk device executes, for each of unexecuted commands, a first operation to estimate a seek time for executing a corresponding command. The first operation includes acquiring a first force constant of the motor and a second force constant of the motor, and estimating a seek time based on the first and second force constants and a seek distance. The first force constant is determined when the magnetic head is at a start position of a seek operation. The second force constant is determined when the magnetic head is at an end position of the seek operation. The controller determines a command to be executed first out of the unexecuted commands based on the estimated value of the seek time obtained by the first operation for each of the unexecuted commands.

Claims20

Dependent claims

A magnetic disk device comprising:

a magnetic disk;
a magnetic head configured to access the magnetic disk;
a motor configured to execute a seek operation to move the magnetic head in a radial direction of the magnetic disk;
a first memory configured to store commands, each being unexecuted and each requesting an access to the magnetic disk;
and
a controller configured to
execute, for each of the commands, a first operation to estimate a first time required for a seek operation for executing a corresponding command, the first operation including
acquiring a first force constant and a second force constant, the first force constant being a force constant of the motor determined when the magnetic head is at a start position of the seek operation for executing the corresponding command, the second force constant being a force constant of the motor determined when the magnetic head is at an end position of the seek operation for executing the corresponding command, and
estimating the first time based on the first force constant, the second force constant, and a first distance being a movement distance of the magnetic head by the seek operation for executing the corresponding command, and
determine a command to be executed first out of the commands based on an estimated value of the first time obtained by the first operation executed for each of the commands.

7 more elements

A method of controlling a magnetic disk device, the magnetic disk device including a magnetic disk, a magnetic head accessing the magnetic disk, and a motor executing a seek operation to move the magnetic head in a radial direction of the magnetic disk, the method comprising:

executing, for each of commands, a first operation to estimate a first time required for a seek operation for executing a corresponding command, the commands each being unexecuted and each requesting an access to the magnetic disk, the first operation including
acquiring a first force constant and a second force constant, the first force constant being a force constant of the motor determined when the magnetic head is at a start position of the seek operation for executing the corresponding command, the second force constant being a force constant of the motor determined when the magnetic head is at an end position of the seek operation for executing the corresponding command, and
estimating the first time based on the first force constant, the second force constant, and a first distance being a movement distance of the magnetic head by the seek operation for executing the corresponding command;
and
determining a command to be executed first out of the commands based on an estimated value of the first time obtained by the first operation executed for each of the commands.

2 more elements

Dependencies are inferred from the claim text.