Abstract: There is provided a method of making an optical polymer waveguide having an arbitrary refractive index profile, the method including: a) providing a first input optical beam having a first beam intensity profile and a second input optical beam having a second beam intensity profile; b) combining the first and second input optical beams to form an output optical beam having an output beam intensity profile; and c) forming the optical waveguide on a substrate by: exposing the optical materials of the waveguide to the output optical beam; and curing the optical materials using said output optical beam.

Abstract: A method of, and apparatus for, network communication between a client computer initiator and a target data store. The method includes requesting, by the initiator, a data transfer session between the initiator and the target over a network. The request specifies quality of service parameters for the data transfer session. The method further includes receiving, from the target, a response accepting or denying the data transfer session based on the quality of service parameters; and establishing the data transfer session between the initiator and the target if the request is accepted. An advantage in communicating QoS requirements automatically on a per session basis between a client computer initiator and a target data storage resource is that QoS guarantees can be improved because the QoS determination can be carried out at the time the data transfer session is required.

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: An apparatus and method of providing conditional access to an electronic data store including a storage controller and a data storage resource. The method includes receiving, at the storage controller, a network request for access to the data storage resource from a client, the request including at least one required parameter defining the requested connection, obtaining information on the performance of the data storage resource, determining, based upon the information, whether a) the data storage resource can meet the or each required parameter of the request; and b) meeting the or each required parameter of the request will not violate any previously agreed parameters defining existing connections on the data storage resource; and denying the request if at least one of a) and b) are determined to be negative.

Abstract: A method of controlling the capacity of a virtual storage system provided on a physical storage system, the method including: providing a control program on the physical storage system; coupling additional virtual storage to the virtual storage system on the physical storage system; providing control data on the additional virtual storage; with the control program, reading the control data and configuring the virtual storage system accordingly. A corresponding virtual storage system is also provided.

Abstract: There is provided a method of making an optical polymer waveguide having an arbitrary refractive index profile, the method including: a) providing a first input optical beam having a first beam intensity profile and a second input optical beam having a second beam intensity profile; b) combining the first and second input optical beams to form an output optical beam having an output beam intensity profile; and c) forming the optical waveguide on a substrate by: exposing the optical materials of the waveguide to the output optical beam; and curing the optical materials using said output optical beam.

Abstract: A method of, and apparatus for, network communication between a client computer initiator and a target data store. The method includes requesting, by the initiator, a data transfer session between the initiator and the target over a network. The request specifies quality of service parameters for the data transfer session. The method further includes receiving, from the target, a response accepting or denying the data transfer session based on the quality of service parameters; and establishing the data transfer session between the initiator and the target if the request is accepted. An advantage in communicating QoS requirements automatically on a per session basis between a client computer initiator and a target data storage resource is that QoS guarantees can be improved because the QoS determination can be carried out at the time the data transfer session is required.