Abstract: A data storage server may store a data packet generated by a client in a first server memory prior to the data packet being migrated to a third server memory of the data storage server by a server controller in response to a server data migration module. The data packet may be moved to satisfy a quality of service agreement between a host and the client. The data packet can be proactively copied to a second server memory by the server controller in response to the migration of the data packet from the first to the third server memories.

Abstract: A data storage system can provide low cost and optimized performance with a cartridge housing multiple separate data storage devices and each of the data storage devices being concurrently engaged by a device player. The device player may have a processor configured to analyze mechanical performance of each data storage device and data performance of data resident in each data storage device.

Abstract: A data storage system can provide low cost and optimized performance with a cartridge housing multiple separate data storage devices and each of the data storage devices being concurrently engaged by a device player. The device player may have a processor configured to analyze mechanical performance of each data storage device and data performance of data resident in each data storage device.

Abstract: Apparatus and method for managing data in a hybrid data storage device. In some embodiments, the hybrid data storage device has a hard disc drive (HDD) controller circuit coupled to non-volatile rotatable storage media and a solid state drive (SSD) controller circuit coupled to non-volatile solid state memory. A local memory stores a map structure which identifies logical addresses of current version data sets stored in the solid state memory. A top level controller circuit operates responsive to the map structure to direct a selected host data transfer access command to the HDD or SSD controller circuit. The map structure may be arranged as a plurality of discrete logical address sequences, where a gap is provided between each adjacent pair of the discrete logical address sequences in the map structure.

Abstract: A data storage server may store a data packet generated by a client in a first server memory prior to the data packet being migrated to a third server memory of the data storage server by a server controller in response to a server data migration module. The data packet may be moved to satisfy a quality of service agreement between a host and the client. The data packet can be proactively copied to a second server memory by the server controller in response to the migration of the data packet from the first to the third server memories.

Abstract: Apparatus and method for managing data in a hybrid data storage device. In some embodiments, the hybrid data storage device has a hard disc drive (HDD) controller circuit coupled to non-volatile rotatable storage media and a solid state drive (SSD) controller circuit coupled to non-volatile solid state memory. A local memory stores a map structure which identifies logical addresses of current version data sets stored in the solid state memory. A top level controller circuit operates responsive to the map structure to direct a selected host data transfer access command to the HDD or SSD controller circuit. The map structure may be arranged as a plurality of discrete logical address sequences, where a gap is provided between each adjacent pair of the discrete logical address sequences in the map structure.

Abstract: An apparatus and method for determining the configuration of a disc drive head-disc assembly (HDA). The HDA includes an array of rotatable discs and an actuator adjacent the discs, with the actuator supporting a maximum number of heads in a fully populated configuration and a reduced number of heads in a depopulated configuration. Each head is disposed at a unique head position. A servo circuit determines an impedance of a selected head position having a head when the disc drive is fully populated but not when the disc drive is depopulated. The servo circuit identifies this configuration of the HDA in relation to the determined impedance, and initializes the drive accordingly.

Abstract: Apparatus and method for selecting an optimum gain for an amplifier used to amplify readback signals transduced from a magnetic recording disc in a disc drive. The amplifier is provided with a first value of gain, which is used to amplify a readback signal to generate an amplified readback signal. The amplified readback signal is in turn applied to an automatic gain control circuit comprising a variable gain amplifier. The variable gain amplifier applies a variable gain from a selected range to the amplified readback signal to maintain an amplitude of an output signal provided by the automatic gain control circuit at a nominal amplitude. The acceptability of the first value of gain for subsequent use by the amplifier is determined in relation to a magnitude of the variable gain applied by the variable gain amplifier.

Abstract: Method and apparatus for optimizing the read/write channel error recovery process in a disc drive. An error recovery table comprising a plurality of sequentially ordered corrective operations is provided so that, upon receipt of an error from the disc drive read/write channel, the corrective operations are sequentially performed in an attempt to correct the error. At such time that a selected one of the corrective operations results in the correction of the error, the table is reordered so that the selected one of the corrective operations is advanced in the table sequence, and the reordered table is used upon the occurrence of the next error. Additionally, a series of free retries is performed prior to the operation of the error recovery table.

Abstract: A method for following data tracks on data surfaces of a disc drive by organizing the data tracks in concentric cylinders including servo tracks on a dedicated servo surface and following servo tracks with a servo transducer that is offset from the servo track to align selected data transducers with the data tracks. To measure the offset for each data surface, a calibration correction track is written to one data surface while a track on the servo surface is followed and the correction track is read by a thermal calibration circuit while following the servo track with an offset to obtain a calibration correction indicative of electronic offsets in the thermal calibration circuit.

Abstract: A mechanically operated, gravity-assisted display device has the capability of being remotely controlled by an unskilled operator to display current numeric pricing indicia for a product or other alpha-numeric indicia for any required purpose. The device is ideally suited for displaying the unit price of gasoline on an elevated sign at a filling station. Multiple gravity-biased sliding panels which are arrayed to form variable indicia are operated remotely by flexible suspension elements equipped individually with fixed enlargements. Interchangeable coded remote operating cards for groups of the flexible suspension elements have passages through which predetermined enlargements may pass while other enlargements are blocked. Movement of the block enlargements with the flexible suspension elements to which they are attached under influence of the coded cards establishes the required change of displayed indicia.