Abstract: A servo write head that provides fast servo pattern writing and improved tape manufacturing speed is provided. The write head may be fabricated using thin-film fabrication techniques. A coil is formed on a bottom pole of the write head. The coil has a plurality of turns that enable the write head to generate a magnetic field sufficient for writing data with reduced current. The inductance of the coil is reduced due to its small dimensions. Reduced inductance of the coil may enable increased switching frequency of the write head, allowing data to be written at a higher frequency. The write head includes a planar top pole coupled to the bottom pole. The top pole has more than one write gap is formed therein.

Abstract: A system and method for minimizing non-linearity errors induced in output drive voltage of a transmitter circuit due to on-chip process, voltage, and temperature (PVT) variations. The system including an oscillator for converting an input reference bias voltage into a clock output signal, where the input reference bias voltage varies in response to PVT variations. Also included is a counter for counting the clock output signal and generating a count value corresponding to the clock output of the oscillator. A comparison module operatively coupled to the counter compares the count value with a pre-simulated count value to generate an error signal. Based on the error signal generated by the comparison module, a correction logic adjusts an output drive signal of the transmitter circuit making it immune to PVT variations.

Abstract: An apparatus and method for reading out data recoded on a tape with a read head is provided. A command processing unit receives a request for reading out old data behind EOD of new data. A channel input/output unit receives, data read out with a read head and a buffer managing unit receives this data. A header information determining unit determines whether this data includes header information of the old data. If it is determined that this data includes the header information of the old data, a data set determining unit determines whether a data set is extractable from this data. If it is determined that data set is not extractable, a move signal output unit outputs a signal for moving the read head in a direction of the new data.

Abstract: A method of manufacturing thin closure magnetic read/write heads, such as magnetic tape heads is provided. The method provides improved flexural strength of the closure so that the closure breakage during fabrication of the heads is mitigated and closure thickness is reduced. An array of chips is fabricated on a wafer. The array is closed, with a closure strip bonded to each row of the array. Closures span only the length of a row, so that the closures are not subjected to flexure during processing and breakage due to flexure is mitigated. Side bars are bonded to the array to form a column with dimensions similar to prior art columns. This allows columns manufactured by the invention to undergo additional processing using existing processes.

Abstract: A system and method for restoring a computing system to a first operating state associated with a first system software code installed on the computing system is provided. The method comprises installing a second system software code on the computing system, while the system is operating in the first operating state. The second system software code is activated and the first system software code is deactivated to cause the computing system to operate in a second operating state. The first system software code is activated and the second system software code is deactivated to cause the system to return to the first operating state, if activation of the second system software code causes the system to operate in an undesirable manner.

Abstract: An apparatus and method for controlling a disk drive is provided. A disk lubricant sweep component for periodically initiates a disk lubricant spreading action. A disk data read check component checks data at one or more LBAs during the disk lubricant sweep. The apparatus may cache data from LBAs that have been checked by the disk data read check component and found correct and record LBAs that have been found correct, so that they can be omitted from subsequent operation of the read check component. The apparatus may further comprise an error checking and correcting component for checking and correcting data found incorrect by reason of a soft error, and an error reporting component for reporting on one or more LBAs that have been checked and found incorrect by reason of a hard error.

Abstract: A data storage resynchronization system is provided. The system includes a primary site having a primary server, primary storage unit, primary replication agent, and a primary storage controller. Data is written to primary pages on the primary storage unit upon receiving a command to do so from the primary server. A secondary site has a secondary server, secondary storage unit, secondary replication agent for receiving a command from the primary replication agent to write the data at the secondary site and secondary storage controller. Data is written to secondary pages on the secondary storage unit upon receiving a command to do so from the secondary replication agent when the secondary and primary pages correspond, and means for comparing corresponding pages and sending primary pages to the secondary replication agent for replacement of corresponding secondary pages at the secondary site where page-change indicators of the corresponding pages do not match.

Abstract: A storage system has a storage controller for an array of storage disks, the array being ordered in an sequence of write groups. A write cache is shared by the disks. The storage controller temporarily stores write groups in the write cache, responsive to write groups being written, and lists the write groups in order of their sequence in the array and in circular fashion, so that a lowest is listed next to a highest one of the write groups. The storage controller selects the listed write groups in rotating sequence. Such a write group is destaged from the write cache to the disk responsive to i) the selecting of the write group and ii) a state of a recency indicator for the write group, wherein the recency indicator shows recency of writing to the write group.

Abstract: A system and method for writing data to a magnetic tape that may provide improved data writing and throughput is provided. First data accumulated in the buffer is written to a temporary recording area on the tape. The first data is then written to a normal recording area on the tape. Second data may be received while the first data is rewritten to the normal recording area. Second data received during data rewriting is accumulated in an area of the buffer not currently being accessed. This makes it possible to handle another write request from a host during rewrite. The second data may be written to the normal recording area so that the second data is contiguous with the first data.

Abstract: An apparatus achieves data communications between a data storage controller and data storage devices within a data storage system via an optical network. The apparatus includes a wavelength division multiplexing logic for simultaneously establishing, on the optical network, a number of arbitrated communications loops between the controller and the data storage system, for communicating data between the controller and the storage devices.

Abstract: An apparatus operable with a host and a data storage component for detecting a storage device susceptible to failure under I/O workload is provided. The apparatus includes a selector component for selecting a pair of storage devices in the data storage component. A data migration control component is provided for initiating migration of data from a first to a second storage device of the pair of storage devices. An I/O workload mirroring component is provided for mirroring an I/O workload from a first of the pair of storage devices to a second of the pair of storage devices. A storage device failure detecting component for detecting failure of one of the pair of storage devices is also included. The selector component further comprises a timer component for periodically initiating the selecting.

Abstract: A storage network control apparatus is operable to present virtualized storage to a host system and includes a monitoring component, an analysis component, a detection component, and a migration component. The monitoring component is for monitoring input/output (I/O) activity for virtual storage logical units over time. The analysis component is for identifying a repeating instance of peak I/O activity for a virtual storage logical unit over time and for generating a predictive signature therefrom. The detecting component is for identifying an instance of such a predictive signature. The migration component is responsive to the detecting component, and is for migrating data mapped by the virtual storage logical unit across additional real storage units to improve the I/O performance of the virtual storage logical unit prior to a recurrence of the repeating instance of peak I/O activity. A corresponding logic arrangement may be incorporated in hardware, software or a combination thereof.

Abstract: A method, a magnetic field sensor, and an electronic device measure and determine the magnitude and/or the direction of a magnetic field. The magnetic sensor is based on at least a first magnetoresistive-layered structure having an electric resistance depending on the magnitude of the magnetic field. The magnetic sensor generates at least a first offset magnetic field. The magnitude and the direction of the offset magnetic field can be modified to compensate the magnetic field. The electric resistance of the magnetoresistive-layered structure depends on the superposition of magnetic field and offset magnetic field. A maximum electric resistance indicates that the magnetic field is compensated by the offset magnetic field. In this case the magnitude of the magnetic field corresponds to the magnitude of the offset magnetic field, and the direction of the magnetic field is given by the reversed direction of the offset magnetic field.

Abstract: A tape recording system is provided for coupling the angular velocities of a pair of roller guides disposed one on either side of a head assembly. In one embodiment, the roller guides each comprise cylindrical first and second surfaces wherein the first surfaces guide a tape over the head assembly. An idler bearing comprising a cylindrical ring having an inside diameter surface engages in rolling contact the second surfaces of the pair of roller guides, thereby coupling the angular velocities of the pair of roller guides. In another embodiment, an idler bearing comprises a roller having an outside diameter surface that engages the surfaces of a pair of roller guides on each side of the head to couple the angular velocities of the pair of roller guides.

Abstract: A write/read control method for recording at least one datum on a magnetic tape within a predetermined distance is provided. The method includes sequentially accumulating a plurality of blocks of data of variable length in a buffer divided into fixed length segments and writing the contents of each segment to the tape. If the segment contains at least one block of data, the data is written to the tape as a dataset and if the segment does not contain any data, then a null dataset is written to the tape within the predetermined distance. The predetermined distance may vary depending upon the format of a tape drive embodying the method. In response to a request to read a block of data, reading at least one dataset that includes the requested block of data from the tape to segments in the buffer, and reading the requested block of data for invalidating data transfer of a null dataset in the segment. By invalidating the transfer of a null dataset, blocks of data separated by the null dataset can be reconstructed.

Abstract: In a lead overlay (LOL) type of read head first and second insulation layers are employed with the first insulation layer being located between a top surface of a first hard bias layer and a first lead layer and the second insulation layer is located between the top surface of a second hard bias layer and a second lead layer for minimizing a shunting of a sense current through the hard bias layers into a read sensor.

Abstract: A method for optimizing UDMA transfer signals parameter that functions independently of a computer system is provided. The method of the invention utilizes UDMA CRC errors to adjust an optimized UDMA transfer signal parameter. A total error rate is logged for each selected parameter for determining the parameter with the lowest total error rate. The method functions continuously, to provide reduced CRC error generation and data corruption, and enhanced UDMA transfer signal integrity.

Abstract: A method for dynamic in-situ characterization of in-plane and out-plane thermal drift of a hard disk drive head suspension is provided. A first data track is written. Amplitude and amplitude modulation of the write data signal are measured and track center is determined. Data tracks are then written for a selected time period. Amplitude and amplitude modulation of the write data signal is measured and a new track center of a last data track is determined. Any difference between the track center of the first data track and the track center of the last data track represents in-plane drift. The amplitude and amplitude modulation of the two write data signals is compared and any difference between the measured values is proportional to out-plane drift.