Abstract: Systems and processes are disclosed to preserve data integrity during a storage controller failure. In some examples, a storage controller of an active-active controller configuration can back-up data and corresponding cache elements to allow a surviving controller to construct a correct state of a failed controller's write cache. To accomplish this, the systems and processes can implement a relative time stamp for the cache elements that allow the backed-up data to be merged on a block-by-block basis.

Abstract: An apparatus includes a substrate. A laser is formed on a non-self supporting structure and bonded to the substrate. A waveguide having a gap portion is deposited proximate the laser. The waveguide is configured to communicate light from the laser to a near-field transducer (NFT) that directs energy resulting from plasmonic excitation to a recording medium. An optical isolator is disposed over the gap portion.

Abstract: An apparatus comprises a slider comprising an air bearing surface (ABS). The slider comprises a reader, a writer, and a reader heater. The reader heater is configured to cause a protrusion of the ABS proximate the reader, and the reader heater comprises a first planar loop and a second planar loop, wherein the first and second loops are in the same plane.

Abstract: An apparatus comprises a substrate. A laser is deposited above the substrate. The laser includes one or more non-self-supporting layers of crystalline material. A metallic adhesive is disposed between the laser and the substrate. The metallic adhesive is configured to adhere the laser to the substrate. A waveguide is deposited proximate the laser. The waveguide is configured to receive light from the laser and direct the light to a recording medium.

Abstract: A DNA sequencing device, and related method, which include an electrode and a plurality of spaced apart alignment structures. The electrode defines an electrode gap, the electrode being operable to detect a change in tunneling current as a DNA strand passes through the electrode gap. The plurality of spaced apart alignment structures are arranged to position nucleotides of the DNA strand in a predetermined orientation as the DNA strand passes through the electrode gap.

Abstract: A storage controller is provided. The storage controller includes circuitry configured to utilize a format command to change a storage volume coupled to the storage controller from a first format to a second format and memory configured to store a data structure for first and second format indications for the storage volume. The storage controller determines if a selected band is initialized to the second format, and if the selected band is not initialized to the second format, the storage controller initializes the selected band to the second format and updates the data structure to indicate the selected band is initialized to the second format.

Abstract: A testing system includes a production-type laser having optical modes of a production laser that interfaces with an optical path of a heat-assisted magnetic recording (HAMR) slider. A far-field light illumination path delivers excitation light from the production-type laser to the optical path of the HAMR slider, the excitation light being emitted from an air bearing surface (ABS) of the HAMR slider. Optics receive the emitted light from the ABS and distribute the emitted light to one or more sensors. The system determines, based on signals received from the one or more sensors, a depolarization of the emitted light and a coupling efficiency of the HAMR slider. The system may also measure light reflecting out of the optical path and Fourier transform these measurements to determine locations of reflections within the optical path.

Abstract: A system includes an enclosure with an air inlet end, an air outlet end, an upper wall, and a lower wall. The system also includes air movers positioned near the air outlet end, a first memory module positioned near the air inlet end at a first orientation, and a second memory module positioned near the air inlet end at a second orientation that is opposite the first orientation.

Abstract: Sync-mark (SM) detection recovery techniques for HDDs tend to be slow and cumbersome. Typical approaches often require an entire read command to be aborted and multiple subsequent read commands with significant firmware intervention. Should a data sector be unreadable, an example recovery technique for HDDs is recursive read averaging (RRA). Using RRA, samples for failed sector reads are stored in memory. When a sector is subsequently read, the samples are averaged and replace the prior sample stored in memory. The averaged samples are then used to decode the sector. Should SMs associated with data fragments making up a sector be unreadable, the data fragments are unreadable, rendering the sector unreadable. The systems and methods described herein are used to recover previously unreadable SMs. When updated data fragments are subsequently recombined, the confidence level in the overall sector is improved, which increases the likelihood of a successful decode of the sector.

Abstract: Use of a deduplication module remote from a storage system for storage of data subject to deduplication by the remote deduplication module. The storage system may generate a hash of target data and send the hash of the target data to the remote deduplication module. The remote deduplication module may access a hash database corresponding to the storage system and apply a deduplication algorithm on the hash. In turn, information regarding a deduplication result may be returned to the storage system which may either store the unique target data or update a mapping between the target data and duplicate existing data in a persistent storage of the storage device. The remote deduplication module may be executed by scalable cloud resources such that the computational resources dedicated to the deduplication module may be scaled.

Abstract: A data storage device (DSD) includes a base-deck, a disc above the base-deck, and a shaft extending perpendicular from the base-deck. The DSD also includes a head stack assembly (HSA) including a head gimbal assembly having a load beam and a head at a first end of the HSA. The head interacts with a surface of the disc. The HSA also includes a second end movably mounted on the shaft. The DSD additionally includes an elevator that linearly moves the HSA along the shaft to adjust a distance between the load beam and the surface of the disc in response to receiving a feedback signal associated with the interaction of the head with the surface of the disc. The feedback signal is one of a plurality of feedback signals employed by the elevator to adjust the distance between the load beam and the surface of the disc.

Abstract: A secret sharing scheme in which a trust structure of the parties receiving a share of the secret is encoded in the shares. In this regard, an access structure defining an authorized set of participants may be based, at least in part, on the encoded trust structures. The secret sharing scheme includes a secret generator that generates the shares distributed to the parties. In turn, an authorized set of participants as defined by the access structure may provide shares to a dealer for reconstruction of the secret. However, if the participants requesting secret reconstruction are not an authorized set of participants, the secret reconstruction fails. In this regard, secret sharing with asymmetrical trust structures may be provided in which the trust structures are not known by other parties in the scheme.

Abstract: An apparatus includes a housing, a data storage magazine configured to hold a plurality of data storage devices, and a movable carriage disposed within the housing that is configured to selectively couple the data storage devices to a host device. The data storage magazine includes a set of magazine signal paths configured to provide signals to the plurality of data storage devices. The movable carriage includes a set of carriage signal paths configured to provide signals to the plurality of data storage devices. The apparatus includes a controller configured to power the plurality of data storage devices by selectively routing the signals via the set of magazine signal paths or the set of carriage signal paths.

Abstract: A disk drive comprises non-volatile rotatable media and a controller operatively coupled to the non-volatile rotatable media. The controller is configured to receive a series of host commands to be executed by the controller and generate a command execution sequence comprising the series of host commands. A task manager, integral or coupled to the controller, is configured to receive a plurality of background tasks comprising a least two priority background tasks to be executed by the controller along with execution of the series of host commands, and insert one or more of the at least two priority background tasks into the command execution sequence while maintaining a specified ratio of priority background task execution and host command execution substantially constant. The controller is configured to execute the command execution sequence with the one or more inserted priority background tasks.

Abstract: An apparatus includes a housing, a data storage magazine configured to hold a plurality of data storage devices, and a movable carriage disposed within the housing that is configured to selectively couple the data storage devices to a host device. The data storage magazine includes a set of magazine signal paths configured to provide signals to the plurality of data storage devices. The movable carriage includes a set of carriage signal paths configured to provide signals to the plurality of data storage devices. The apparatus includes a controller configured to power the plurality of data storage devices by selectively routing the signals via the set of magazine signal paths or the set of carriage signal paths.

Abstract: Fluoropolyether compounds that can be used as a lubricant, such as for magnetic recording media. The compounds have a terminal group that includes a phenol or benzene. The fluoropolyether compounds reduce the head to media distance while keeping comparable reliability in a hard disk drive compared to current industrial widely used fluoropolyether based lubricants.

Abstract: A data storage device includes a ramp that supports at least one head, and a retraction mechanism that moves the ramp from a non-retracted position to a retracted position. The movement of the ramp is enabled by at least one of expansion or contraction of at least a portion of the retraction mechanism. The data storage device further includes a ramp retraction control module operably coupled to the retraction mechanism. The ramp retraction control module provides the retraction mechanism with a first control signal that causes the retraction mechanism to move the ramp from the non-retracted position to the retracted position.

Abstract: A method and apparatus for private information retrieval from a database, wherein the retrieval includes providing a covering vector for a plurality of database entries of the database. The covering vector is defined such that an inner product of the covering vector is zero with more than one member of a covering vector family that includes the covering vector. The retrieval includes generating database queries based on the covering vector and transmitting the database queries to at least two servers. An identical copy of the database may be stored on each of the at least two servers. Shares are received in response to the query, and these shares are aggregated, and a reconstruction algorithm executes to reconstruct the query results.

Abstract: The technology disclosed herein provides a method to control the resources used in a device. An implementation of such a method includes generating a device configuration ledger block based on initial assembly of components of a storage device, storing the device configuration ledger block on a node of a distributed ledger, detecting an activation of the device; in response to detecting the activation of the device, generating a current distributed ledger block based on current assembly of components of the storage device, comparing the current distributed ledger block with the device configuration ledger block, and in response to determining that the current distributed ledger block does not match with the device configuration ledger block disabling the operation of the device.

Abstract: A set of N network-coupled edge storage nodes are selected to store a file of size |F|. The N edge storage nodes have heterogeneous storage availability and are ordered from a largest storage availability at the first edge storage node to a smallest availability at the Nth edge storage node. A value Z<N is selected, such that an attacker having access to Z edge storage nodes is unable to decode any partial information of the file. The first through Z+1th edge storage nodes are assigned a same packet size. Keys are stored in the first Z edge storage nodes and independent linear combinations of the keys combined with partitions of the file are stored in the Z+1th to the Nth edge storage nodes.