Abstract: A data storage system is provided with command queue controller circuitry for positionally pushing pending access commands from a command queue to a selected target zone of a storage space. A method is provided for dividing a storage space into a plurality of LBA zones, selecting a target zone in relation to a number of pending access commands for each of the plurality of LBA zones, and pushing access commands to the target zone.

Abstract: The present invention is a method of recovering data in a system that stores data in identifiable storage segments. The method includes scanning at least one storage segment for a read error. The method also includes performing a read recovery operation in an attempt to recover a read error. The method logs recovered read errors as a function of the read recovery operation.

Abstract: Method and apparatus for transferring speculative data in lieu of requested data in a data transfer operation. First data are transferred in response to an execution of a first pending command. Speculative data are transferred instead of second data associated with a second pending command during a next available latency period for the second data, preferably when the speculative data are adjudged as having a utility greater than a utility of the second data. The first and second commands are preferably received in a queue and a command execution algorithm identifies the second command as a next best command to be executed after execution of the first command. The above steps are preferably carried out by a controller of a data storage device.

Abstract: A data storage system is provided with command queue controller circuitry for positionally pushing pending access commands from a command queue to a selected target zone of a storage space. A method is provided for dividing a storage space into a plurality of LBA zones, selecting a target zone in relation to a number of pending access commands for each of the plurality of LBA zones, and pushing access commands to the target zone.

Abstract: A data storage device mirrors data on a data storage medium. The multiple instances of data are synchronized in order to optimize performance of the reading and writing, and the integrity of the data. Preferably, a data storage device is allowed to defer writing multiple copies of data until a more advantageous time.

Abstract: A unified debug system with multiple user-configurable trace volumes is disclosed, including embodiments as a system, a method, and a computer-readable medium. Embodiments of the present invention provide more robust and flexible solutions for introducing configurable trace volumes to firmware, allowing a user to specify firmware system configurations for trace buffers, trace frames, and trace volumes, and offer other advantages over the prior art. One embodiment of the present invention pertains to a system that includes a firmware component comprising firmware, and a firmware interface communicatively connected to the firmware component. The firmware includes a plurality of trace volumes for storing a plurality of trace entries. The trace volumes are user-configurable through the firmware interface. The plurality of trace volumes includes first, second and third trace volumes. The first trace volume includes storing at least some of the trace entries to a trace buffer in a first volatile memory component.

Abstract: A data storage device mirrors data on a data storage medium. The multiple instances of data are synchronized in order to optimize performance of the reading and writing, and the integrity of the data. Preferably, a data storage device is allowed to defer writing multiple copies of data until a more advantageous time.

Abstract: A data storage device mirrors data on a data storage medium. The multiple instances of data are synchronized in order to optimize performance of the reading and writing, and the integrity of the data. Preferably, a data storage device is allowed to defer writing multiple copies of data until a more advantageous time.

Abstract: A method and a system is provided for increasing reliability of data stored in storage segments by increasing redundancy data and by permitting user data to fit around defective locations in the storage segment. User data is compressed and reserved for a portion of a storage segment having a data size corresponding to an uncompressed size of the user data. The compressed user data is written to the reserved portion of the storage segment and a pad byte pattern is written to any remaining portion of the reserved portion of the storage segment. The remaining portion of the reserved portion of the storage segment is designated as unused.

Abstract: A data storage subsystem in a distributed storage system having a plurality of predictive failure analyzing data storage devices. The subsystem furthermore has a circuit that is responsive to a predicted failure indication by a data storage device in relation to predetermined rules stored in memory for deterministically initiating a preventive recovery either by a data recovery procedure in the data storage device or by a fault tolerance storage arrangement in the subsystem.

Abstract: The present invention is a method of recovering data in a system that stores data in identifiable storage segments. The method includes scanning at least one storage segment for a read error. The method also includes performing a read recovery operation in an attempt to recover a read error. The method logs recovered read errors as a function of the read recovery operation.

Abstract: A method for determining a speculative data acquisition in conjunction with an execution of a first access command relative to an execution of a second access command through execution of the read look ahead routine is disclosed.

Abstract: A method and apparatus are provided for scheduling commands. A tentatively scheduled command is selected from a command queue for execution. An extended scheduling period, which represents a portion of a time between when a running command is completed and the tentatively scheduled command is scheduled to begin, is then determined. During the extended scheduling period, it is determined that a newly arriving command outperforms the tentatively scheduled command. As a result, the newly arriving command replaces the tentatively scheduled command.

Abstract: A data storage device mirrors data on a data storage medium. The multiple instances of data are synchronized in order to optimize performance of the reading and writing, and the integrity of the data. Preferably, a data storage device is allowed to defer writing multiple copies of data until a more advantageous time.

Abstract: A method of controlling an actuator in a disc drive to move a data head to implement an access in accordance with the invention includes determining a first rotational position corresponding to a rotational position of the data head when the access will start and determining a second rotational position corresponding to a rotational position of the data head at a destination of the access. Subsequently, an access time required to move the data head from the first rotational position on a current or initial track to the second rotational position on a destination track using a fastest of multiple seek profiles is determined. A slower or slowest of the multiple seek profiles which can be used to move the data head from the first track to the second track within the access time is determined. Subsequently, the actuator is controlled using the determined slower or slowest of the multiple seek profiles to implement the access. In addition, a disc drive is provided.

Abstract: Methods and control systems for delaying a seek once a command is received to further load a buffer with read look ahead data are described. The methods involve calculating when or at what point the prefetching should cease and a seek should be initiated so that the actuator arm arrives at a new track just in time to begin reading the target data. The control systems include a processor that instructs a servo control to hold the actuator on a track while data is prefetched and loaded into a buffer until a seek must be initiated to allow the actuator to arrive at the new track just in time to begin reading the new target data.

Abstract: A disc storage system having a host computer interface adapted to coupled to a host computer, a disc storage medium having a disc surface and a spindle motor coupled to the disc adapted to rotate the disc. A transducer is positioned for reading and writing data on the disc surface. The system further includes a volatile memory write cache and a non-volatile memory write cache adapted to store data during a power loss. A method is also provided for storing data prior to writing the data in a non-volatile memory cache in a disc storage system.

Abstract: A method formats disc surfaces in a disc drive for storage of data in a group of tracks on the disc surfaces. The disc drive performs seek operations to seek among cylinders on the disc surfaces as a function of time according to an actual seek profile. An approximation of the actual seek profile is determined such that the actual seek profile falls within the approximation. The disc surfaces are formatted according to the approximation of the actual seek profile.

Abstract: A data storage system and method of scheduling commands in such a data storage system are provided in which commands are stored in a command sort queue and a scheduled command queue. Commands in the command sort queue are sorted and assigned a priority. Eventually, commands in the command sort queue are transferred to the scheduled command queue. Commands in the scheduled command queue are executed without further sorting. The desired queue depth or size of the scheduled command queue is determined as a function of both the queue depth of the command sort queue and a command execution rate value which is indicative of the rate at which commands in the scheduled command queue are executed. The desired queue depth may be dynamically determined using the queue depth of the command sort queue and the command execution rate value as inputs to a look-up table. The data storage system may include a small computer system interface (SCSI) disc (or “disk”) drive which executes commands from a host system.

Abstract: A data storage device mirrors data on a data storage medium. The multiple instances of data are synchronized in order to optimize performance of the reading and writing, and the integrity of the data. Preferably, a data storage device is allowed to defer writing multiple copies of data until a more advantageous time.