Seagate Technology Incorporated

Kenneth A Haapala

Wenzhong Zhu

Reed David Hanson

Edward Charles Gage

Jon David Trantham

Raye Abdoulie Sosseh

Evgeny R Kharisov

Bin Huang

XingHui Huang

Dwight Russell Kinney

Bruce Douglas Buch

Riyan Alex Mendonsa

John Christopher Morris

Alfredo Sam Chu

Scott Edward Ryun

Dongming Liu

Lin Zhou

Josiah Natan Wernow

Paul William Burnett

Siew Kin Chow

Saravanan Nagarajan

Binh Kim Lieu

Xiong Liu

Kaizhong Gao

Mehmet Fatih Erden

Wei Tian

Brian Thomas Edgar

Jason Wayne Riddering

Joshua Ward Christensen

Ralph William Cross

Tao Zhang

Dustin Mark Cvancara

Gary Ernest Hillukka

Peter Stuart Harllee, Iii

Eric John McCalla

Mark Larry Birtzer

Christopher Thomas Cole

(Peter) Fei Wang

Evgeny Kharlsov

(Leon) Liyang Zhao

A secure cartridge-based storage system includes a set of read/write control electronics on a control board adapted to removably couple with each of a plurality of storage cartridges. The read/write control electronics are adapted to transmit a public key to a target storage cartridge in response to a read/write command received from a host device. The target storage cartridge includes and encryption circuit that authenticates the transmitted public key against a stored public key, accesses a locally-stored encryption key responsive to successful authentication of the public key; and utilizes the locally-stored encryption key to encrypt or decrypt data of the read/write command that is in transit between the storage media and the control board.

On-cartridge encryption key storage for cartridge-based library

A secure cartridge-based storage system includes a set of read/write control electronics on a control board adapted to removably couple with each of a plurality of storage cartridges. For each individual storage cartridge, the read/write electronics are adapted to retrieve a unique device identifier from the storage cartridge; retrieve an encryption key stored on the control board in association with the unique device identifier; and utilize the encryption key to encrypt or decrypt data that is in transit to or from a target storage location on the storage media.

Off-cartridge encryption key storage for cartridge-based library

A data storage device includes a first data storage surface and a second data storage below the first data storage surface. The data storage device also includes a first micro-actuator coupled to a first arm that supports a first head over the first data storage surface, and a second micro-actuator coupled to a second arm that supports a second head over the second data storage surface. The data storage device further includes a coarse actuator, to which the first and second arms are coupled, that positions the first head and the second head between corresponding first and second tracks on the respective first and second data storage surfaces. Micro-actuator drive circuitry finely positions the first head over the first track and the second head over the second track by concurrently driving the first micro-actuator and the second micro-actuator in opposite directions.

Parallel servo control in a data storage device

A recording surface of a magnetic disk is divided into first and second zones. A first head of a first actuator arm assembly reads from and/or writes to the first zone exclusively. A second head of a second actuator arm assembly reads from and/or writes to the second zone exclusively. The first and second head are capable of simultaneously reading from and writing to the recording surface.

Dual actuator storage device utilizing multiple disk zones

HDDs including multiple heads driven by separate actuator spindles can read from or write to one or more platters simultaneously. Simultaneous active heads can be used to increase data rate or for other purposes. The multiple independently-actuated heads can access the same platter or different platters and may be moved across an associated platter surface in a number of different ways. However, multiple independently operating actuators may lead to mechanical coupling between the actuators. For example, as certain resonant frequencies, the movement of one actuator arm may cause unacceptable movement of another actuator arm within the HDD. This mechanical coupling can have detrimental effects on the HDD. The disclosed coupling observer and disable systems detect and mitigate detrimental effects of mechanical coupling between the independently operated actuators.

Magnetic disk device having coupling observers for reducing coupling issues between independently running multi-actuators

An apparatus includes a logical space and first and second physical spaces. The apparatus further includes a map in which first successive alternate logical elements of the logical space are mapped to successive adjacent physical elements of the first physical space, and second successive alternate logical elements of the logical space are mapped to successive adjacent physical elements of the second physical space. A control circuit employs the map to substantially concurrently manage storage of data extents into the first and second physical space by routing a first subset of the data extents into the first physical space, routing a second subset of the data extents into the second physical space, and splitting individual extents of a third subset of the data extents into sub-portions, with at least one of the sub-portions being routed to the first physical space and another sub-portion being routed to the second physical space.

Managing storage device media data rates

A clearance heater of a write head is engaged with a boosted current that exceeds a steady-state current. The steady-state current causes the write head to maintain a desired clearance over a disk during writing, the boosted current being applied before a start of the writing. The boosted current is monotonically decreased before the start of the writing and the steady-state current is applied to the heater after the start of the writing.

Boosted preheat trajectory to obtain desired clearance before writing to disk

Systems and methods for compensating for hysteresis in a disc drive are described. In one embodiment, a method may use an inverse hysteresis model to linearize effects of hysteresis of a microactuator in the disc drive. The hysteresis model may be a Coleman-Hodgdon hysteresis model. The hysteresis of the microactuator may be characterized, and the inverse hysteresis model may be based at least in part on the characterization. The inverse hysteresis model may be used to implement a digital filter. The digital filter may be employed in series with the microactuator to linearize the effects of hysteresis.

Hysteresis compensation in a disc drive

Systems and methods for determining a relationship between write fault threshold and temperature are described. The systems and methods include measuring an operating temperature of the storage device, determining a current operating temperature of the storage device, determining whether the current operating temperature of the storage device satisfies a temperature threshold, and upon determining the current operating temperature of the storage device satisfies the temperature threshold, modifying a write fault threshold associated with a data track of the storage device.

Adaptive write fault thresholds

An apparatus includes a first controller, a second controller, and a coupling compensator. The first controller is configured to generate a first voice coil motor (VCM) control signal in response to a first position error signal. The second controller is configured to generate a second VCM control signal in response to a second position error signal. The coupling compensator is configured to generate a first feedforward correction signal in response to the first VCM control signal. The first feedforward correction signal modifies the second VCM control signal to generate a modified second VCM control signal.

Feedforward compensation for multi-actuator hard drives

A storage device includes a multi-reader transducer head with a first reader and a second reader having an effective cross-track separation equal to a multiple of a defined track-pitch of a storage medium of the storage device. The effective cross-track separation may permit for a simultaneous data read of two non-adjacent data tracks.

Reader design for interlaced magnetic recording

Implementations described and claimed herein includes a storage device comprising a plurality of readers, including a first subset of readers configured to read a first subset of tracks and a second subset of readers configured to read a second subset of tracks, the first subset of tracks being wider than the second subset of tracks. In another implementation, the readers in the first subset of readers are wider than the readers in the second subset of readers. The wider readers may be configured to recover servo information and the narrow readers may be configured to recover data information. The storage devices may include two-dimensional magnetic recording, conventional perpendicular magnetic recording, shingled magnetic recording, multi-sensor magnetic recording, and interlaced magnetic recording.

Magnetic storage device readers

A storage media includes a plurality of servo sectors with embedded servo patterns characterized by one or more servo pattern parameters. Each of the servo sectors has a servo pattern parameter based on a separation between read sensors of a transducer head reading the servo sector.

Servo parameterization for multi-sensor reader

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Minneapolis, MN, United States of America

Kenneth A Haapala