Abstract: A storage device is configured with one or more processes that receive, process, and pass on jobs from a source. The number of jobs received by a process is compared with the number of jobs completed and/or passed on by the process. If the number of jobs that are received is disproportionate to the number of jobs completed and/or passed on by the process, a hang may exist and a corrective action, such as resetting, may be performed along with a request for all or some of the jobs to be resent.

Abstract: A system and methods employ a redistribution module to predict whether there is data stored in an arrayed storage device that is likely to be data that will be highly accessed in the future. The redistribution module locates high-access data on one or more storage components within the array and redistributes it evenly across all storage components in the array so that no single storage component contains a disproportionate amount of the high-access data. Redistributing high-access data evenly across all storage components (e.g., disks) in a storage array helps prevent I/O (input/output) bottlenecking at any single storage component in the array. I/Os are serviced in a more parallel manner which increases the overall performance of the storage array.

Abstract: A block of data is written to a location on a first storage system. Version checking data associated with the block of data and having a predetermined initial value is also written to the first storage system. The version checking data is then written to a second storage system. Upon subsequent writing of data to the same location on the first storage system, the version checking data on the first storage system is incremented and the incremented version checking data is stored on the second storage system. When reading the group of data from the first storage system, the data is validated by comparing the version checking data on the first storage system with version checking data on the second storage system.

Abstract: An array of storage devices is monitored to detect failure of one of the storage devices. Upon detection of a storage device failure, parity data associated with data stored on the failed storage device is identified. Data stored on the failed storage device is reconstructed and stored on unused portions of storage devices that did not fail. The system then updates the parity data associated with the data stored on the failed storage device.

Abstract: A layered optical circuit including a multi-substrate optical circuit. The multi-substrate optical circuit includes a plurality of optical fibers, a first substrate supporting a first portion the optical fibers to form a first optical subcircuit, and a second substrate supporting a second portion of the optical fibers to form a second optical subcircuit. A third portion of the optical fibers between the first and second portions extends between the first and second substrates. Free fibers in the third portion are elongated to permit repositioning of the first and second optical subcircuits in an overlapping arrangement without exceeding a minimum bend radius of each of the optical fibers. The overlapping arrangement of the first and second optical subcircuits forms a layered optical circuit. Accordingly, a layered optical circuit having a large number of fibers and/or a complex circuit pattern may be affixed on a relatively small footprint of a backplane, etc.

Abstract: A system and methods employ a redistribution module to predict whether there is data stored in an arrayed storage device that is likely to be data that will be highly accessed in the future. The redistribution module locates high-access data on one or more storage components within the array and redistributes it evenly across all storage components in the array so that no single storage component contains a disproportionate amount of the high-access data. Redistributing high-access data evenly across all storage components (e.g., disks) in a storage array helps prevent I/O (input/output) bottlenecking at any single storage component in the array. I/Os are serviced in a more parallel manner which increases the overall performance of the storage array.

Abstract: Multiple function bandwidth management systems. Bandwidth-management systems for an optical network are easily assembled by concatenating a plurality of intelligent, miniaturized, bandwidth-management modules (BMM's) together. The BMM's subdivide the wide available spectrum into narrow band segments. Each individual BMM is designed to overcome loss and optimize dispersion, gain, and power or gain equalization for a few channels at a time. Each device includes optical connectors and filters, as well as any other components necessary to direct the band of optical channels through the device's optical path while passing other optical channels within the spectrum to additional devices which can be connected without disturbing existing bandwidth-management modules. Each BMM also includes a digital control module that operates the BMM in any one of a plurality of selectable operating modes.

Abstract: Adjustable optical fiber grating dispersion compensators. The invention provides a fully tunable dispersion compensator with a wide dynamic range. Dispersion compensators according to the invention are based on uniform fiber Bragg grating technology. Individual gratings are tuned so that the gratings, which normally operate in reflection mode, operate in transmission mode with the frequency of interest falling just outside a reflection band edge. Gratings are combined to provide broadband, or multiple-wavelength dispersion. Tuning is provided via transducers coupled to the gratings. A control system can be connected to the transducers to provide a control signal so that the frequencies of the gratings can be dynamically tuned. The control system operates by measuring signals from opto-electronic detectors. The signals are used to determine a fractional spectral power transmitted through a filter. The fractional spectral power is related to the amount of dispersion present in the optical path of the network.

Abstract: Adjustable optical fiber grating dispersion compensators. The invention provides a fully tunable dispersion compensator with a wide dynamic range. Dispersion compensators according to the invention are based on uniform fiber Bragg grating technology. Individual gratings are tuned so that the gratings, which normally operate in reflection mode, operate in transmission mode with the frequency of interest falling just outside a reflection band edge. Gratings are combined to provide broadband, or multiple-wavelength dispersion. Tuning is provided via transducers coupled to the gratings. A control system can be connected to the transducers to provide a control signal so that the frequencies of the gratings can be dynamically tuned. The control system operates by measuring signals from opto-electronic detectors. The signals are used to determine a fractional spectral power transmitted through a filter. The fractional spectral power is related to the amount of dispersion present in the optical path of the network.