Abstract: There is provided a method of recovering configuration metadata from an erasure encoded RAID array. The RAID array includes raw data including a plurality of codewords encoded using Reed-Solomon encoding. The codewords include message data and checksum data, and the configuration metadata includes parameters relating to the layout of the RAID array. The method includes reading, from the RAID array, raw data including message data and checksum data. Then a set of linear equations are defined using the message data and checksum data. The linear equations are then solved and then, from the solved linear equations, one or more parameters relating to the layout of the RAID array are determined.

Abstract: A method of making a waveguide, the method including depositing discrete units of optical core material in a pattern of the waveguide, and controlling the refractive index of the discrete units such that the refractive index of the waveguide varies along its length.

Abstract: The invention provides an amplification module for an optical printed circuit board, the optical printed circuit board comprising plural polymer waveguide sections from independent waveguides, each of the sections being doped with an amplifying dopant, wherein the plural waveguide sections are routed so as to pass through an amplification zone in which the plural polymer waveguide sections are arranged close or adjacent to one another, the amplification module comprising: a pump source comprising plural light sources arranged to provide independently controllable levels of pump radiation to each of the plural waveguide sections. In an embodiment, the amplification module also includes plural polymer waveguide sections corresponding to the plural polymer waveguides of the printed circuit board on which in use the amplification module is to be arranged, each of the sections being doped with an amplifying dopant.

Abstract: A method of defining a layout mapping function for a parity distributed RAID array including a plurality of target objects, the layout mapping function defining the mapping of the group-address space to the target-address space in the array and including a matrix defining a unit space across a plurality of target objects, the matrix Includes columns defining the target objects and rows defining equally-offset sequential units on the target objects, the method including: a) defining, on a computing apparatus, a layout of stripe groups across the target objects by defining a pattern including a plurality of stripe groups into a predetermined pattern and repeating the pattern across the matrix, each stripe group including a plurality of data units and a plurality of parity units; and b) implementing, on a computing apparatus, the layout on the target objects of the RAID array.

Abstract: A method of sampling sensor data from a computing system is presented. The computing system includes a plurality of components and a sensor network for monitoring the computing system. The sensor network includes primary sensor nodes operable to obtain primary parameter data from a measurement of a primary parameter of the components, and secondary sensor nodes operable to obtain secondary parameter data from a measurement of secondary parameters of the components. The method includes: a) obtaining secondary parameter data from secondary sensor nodes relating to components; b) processing, in a computing device, the secondary parameter data; c) determining, based upon determined or pre-determined relationships between the secondary parameters and the primary parameter, a sample rate for the primary parameter data for the components; and d) obtaining primary parameter data from the primary sensor nodes relating to components at the determined sample rate.

Abstract: A method of manufacturing an optical printed circuit board and an optical printed circuit board. The method includes providing a support layer having one or more optical waveguides formed on the support layer, the waveguides having exposed interfaces. A film is provided on one or more of the exposed interfaces, wherein the film has a smoother outer surface than the waveguide interface.

Abstract: A method of writing data to a distributed file system including a file system client, a server and a storage resource target, includes generating, on the client, a write request including a byte stream to be written to the storage resource target; formatting, on the client, the byte stream into sectors in accordance with the T10 protocol, the sectors including a data field and a protection information field, the protection information field including a guard field, an application field and a reference field; computing, on the client, checksum data for the guard field; sending, across a network, the data and the protection information to the server; verifying, in T10-capable hardware on the server, the checksum data for the guard field; verifying, on the storage resource target, the checksum data for the guard field; and storing the data on the storage resource target.

Abstract: Method of defining a layout mapping function for a parity distributed RAID array including target objects, the layout mapping function defining the mapping of the stripe group-address space to the target-address space in the array and including a matrix defining a unit space across target objects, the matrix includes columns defining the objects and rows defining equally-offset sequential units on the objects, the method including: specifying P target objects, where P>1; b) specifying A target objects as spare space, where A<P and A?1; defining a sub-matrix of P? columns, where P?=P?A; defining a layout of stripe groups across the P? target objects in the sub-matrix, each stripe group comprising data units and parity units; adding A columns, representative of the A spare space target objects, to the sub-matrix to form a complete matrix defining the layout mapping function; and implementing the layout mapping function on the objects.

Abstract: The invention provides an optical connector for coupling with a complementary optical connector and for supporting an optical component. The connector comprises a cover moveable between a first and second position. The cover may also comprise a moveable shield and biasing components. There is also provided an optical connector assembly comprising covers that sequentially open. A PCB comprising waveguides and an optical component sub-mount for integrating with the PCB is also presented.

Abstract: An optical alignment system for aligning an optical component is provided. The system includes an alignment component configured to be moveable in a plane and in a fixed relationship with the optical component. Typically the alignment component houses an optical fibre MT ferrule. One or more driving components are further provided typically in the form of a ball headed adjustment screw. The driving components are configured to be moveable, relative to the alignment component, in a first linear direction. At least a component of the first linear direction is parallel with the normal of the plane. The driving component, when forced along the first linear direction and in contact with the alignment component, imparts a force upon the alignment component, in the plane, to move the optical component in the plane. An alignment frame accommodating the driving components may also be provided.

Abstract: The invention provides storage enclosure, comprising an enclosure housing; one or more drawers slidably arranged within the enclosure housing, wherein each drawer has a pivotably mounted midplane having storage media coupled thereto wherein the storage media are coupled to both sides of the pivotably mounted midplane.

Abstract: There is provided a method of writing data to a sector of a storage device, the sector comprising a data field and a protection information field and having identifying information identifying the location of said sector. The method comprises providing data to be written to an intended sector, generating, for said intended sector, a message comprising the data and the identifying information of said intended sector and performing, on said message, error correcting encoding to generate a codeword. The codeword comprises the message and parity information generated from said error correcting coding. The data can then be written to the data field of the sector, and the parity information can be written to said protection information field of the sector.

Abstract: There is provided a method of recovering configuration metadata from an erasure encoded RAID array. The RAID array includes raw data including a plurality of codewords encoded using Reed-Solomon encoding. The codewords include message data and checksum data, and the configuration metadata includes parameters relating to the layout of the RAID array. The method includes reading, from the RAID array, raw data including message data and checksum data. Then a set of linear equations are defined using the message data and checksum data. The linear equations are then solved and then, from the solved linear equations, one or more parameters relating to the layout of the RAID array are determined.

Abstract: A method of sampling sensor data from a computing system is presented. The computing system includes a plurality of components and a sensor network for monitoring the computing system. The sensor network includes primary sensor nodes operable to obtain primary parameter data from a measurement of a primary parameter of the components, and secondary sensor nodes operable to obtain secondary parameter data from a measurement of secondary parameters of the components. The method includes: a) obtaining secondary parameter data from secondary sensor nodes relating to components; b) processing, in a computing device, the secondary parameter data; c) determining, based upon determined or pre-determined relationships between the secondary parameters and the primary parameter, a sample rate for the primary parameter data for the components; and d) obtaining primary parameter data from the primary sensor nodes relating to components at the determined sample rate.

Abstract: There is provided a method of scheduling requests from a plurality of services to at least one data storage resource. The method comprises receiving, on a computer system, service requests from said plurality of services. The service requests comprise metadata specifying a service ID and a data size of payload data associated with said service request, and at least some of said service IDs have service throughput metadata specifying a required service throughput associated therewith. The method further includes arranging, in a computer system, said requests into FIFO throttled queues based on said service ID and then setting a deadline for processing of a request in a throttled queue. The deadline is selected in dependence upon the size of the request and the required service throughput associated therewith. Then, the deadline of each throttled queue is monitored and, if a request in a throttled queue has reached or exceeded the deadline the request is processed in a data storage resource.

Abstract: A method of monitoring the performance of a device is presented, each storage device being operable to receive storage requests and includes a queue for incoming storage requests and a physical storage medium, the method includes: a) obtaining data relating to the device parameters of: throughput of storage requests to the storage device; queue time for one or more requests on the storage device; and the time required to complete one or more storage requests on the storage device; b) generating a model relating to the expected distribution of the device parameters on the storage device during normal operation; c) monitoring the parameters during operation of the storage device; d) comparing the distribution of the monitored parameters during operation of the storage device with the expected distribution of the parameters; and e) identifying a fault on the storage device based on the comparison.

Abstract: A storage system and a method of control of a storage system including plural storage media, at least one SAS expander physically connected to each of the plural storage media and to a controller via plural parallel data channels, the controller being connected to a host CPU arranged in use to execute input/output operations to transfer data to and read data from the plural storage media, the method including: at the expander, varying the available bandwidth for communication with the plural storage media by varying the available number of the plural parallel data channels thereby providing control of the number of input/output operations executed by the host CPU.

Abstract: The invention provides an amplification module for an optical printed circuit board, the optical printed circuit board including plural polymer waveguide sections from independent waveguides, each of the sections being doped with an amplifying dopant, wherein the plural waveguide sections are routed so as to pass through an amplification zone in which the plural polymer waveguide sections are arranged close or adjacent to one another, the amplification module including: a pump source including plural light sources arranged to provide independently controllable levels of pump radiation to each of the plural waveguide sections. In an embodiment, the amplification module also includes plural polymer waveguide sections corresponding to the plural polymer waveguides of the printed circuit board on which in use the amplification module is to be arranged, each of the sections being doped with an amplifying dopant.

Abstract: An electro-optical connector assembly includes a first data connector for arrangement on a first device and a second data connector for arrangement on a second device, the first and second data connectors being for communicating data through free space between the first device and the second device and, a first power connector for arrangement on the first device and a second power connector for arrangement on the second device, the first and second power connectors being for providing wireless power transfer between the first device and the second device.

Abstract: There is disclosed a spinstand for testing a head gimbal assembly. The spinstand includes a gripper operable to grip the head gimbal assembly and a load pick device operable to hold a head gimbal assembly and to move the head gimbal assembly into an exchange position where it can be gripped by the gripper. In the exchange position part of the load pick device registers with the gripper and another part of the load pick device is spaced from the gripper so as to form a space between, in which space at least part of the head gimbal assembly is located in use.