Abstract: In a data storage system with a number of replicas of a file set to one or more replicas, a timer is set to track a time since a last access to the file. Responsive to the timer matching a first timer window threshold, the timer is reset to count to a second timer window threshold and a number of replicas of the file are automatically reduced within the data storage system, wherein the probability that the file will be accessed prior to the first timer window threshold is greater than the probability that the file will be accessed after the first timer window threshold. Responsive to the timer matching the second timer window threshold, the timer is reset to count to a third timer window threshold. Responsive to receiving a read access prior to the timer reaching the third timer window threshold, the number of replicas of the file is increased and the timer reset to count to the second timer window threshold.

Abstract: In a data storage system with a number of replicas of a file set to one or more replicas, a timer is set to track a time since a last access to the file. Responsive to the timer matching a first timer window threshold, the timer is reset to count to a second timer window threshold and a number of replicas of the file are automatically reduced within the data storage system, wherein the probability that the file will be accessed prior to the first timer window threshold is greater than the probability that the file will be accessed after the first timer window threshold. Responsive to the timer matching the second timer window threshold, the timer is reset to count to a third timer window threshold. Responsive to receiving a read access prior to the timer reaching the third timer window threshold, the number of replicas of the file is increased and the timer reset to count to the second timer window threshold.

Abstract: In a data storage system with a number of replicas of a file set to one or more replicas, a timer is set to track a time since a last access to the file. Responsive to the timer matching a first timer window threshold, a number of replicas of the file are automatically reduced within the data storage system, wherein the probability that the file will be accessed prior to the first timer window threshold is greater than the probability that the file will be accessed after the first timer window threshold.

Abstract: In a data storage system with a number of replicas of a file set to one or more replicas, a timer is set to track a time since a last access to the file. Responsive to the timer matching a first timer window threshold, a number of replicas of the file are automatically reduced within the data storage system, wherein the probability that the file will be accessed prior to the first timer window threshold is greater than the probability that the file will be accessed after the first timer window threshold.

Abstract: In a distributed file system with a number of replicas of a file set to two or more replicas, a computer sets a timer to track a time since a last access to the file, wherein the replicas of the file are distributed across two or more nodes within the distributed file system. Responsive to an access to the file prior to the timer reaching a first timer window threshold, the computer resets the timer. Responsive to the timer matching a first timer window threshold, the computer automatically reduces a number of replicas of the file within the distributed file system, wherein the probability that the file will be accessed prior to the first timer window threshold is greater than the probability that the file will be accessed after the first timer window threshold.

Abstract: In a distributed file system with a number of replicas of a file set to two or more replicas, a computer sets a timer to track a time since a last access to the file, wherein the replicas of the file are distributed across two or more nodes within the distributed file system. Responsive to an access to the file prior to the timer reaching a first timer window threshold, the computer resets the timer. Responsive to the timer matching a first timer window threshold, the computer automatically reduces a number of replicas of the file within the distributed file system, wherein the probability that the file will be accessed prior to the first timer window threshold is greater than the probability that the file will be accessed after the first timer window threshold.

Abstract: In a distributed file system with a number of replicas of a file set to two or more replicas, a computer sets a timer to track a time since a last access to the file, wherein the replicas of the file are distributed across two or more nodes within the distributed file system. Responsive to an access to the file prior to the timer reaching a first timer window threshold, the computer resets the timer. Responsive to the timer matching a first timer window threshold, the computer automatically reduces a number of replicas of the file within the distributed file system, wherein the probability that the file will be accessed prior to the first timer window threshold is greater than the probability that the file will be accessed after the first timer window threshold.

Abstract: In a distributed file system with a number of replicas of a file set to two or more replicas, a computer sets a timer to track a time since a last access to the file, wherein the replicas of the file are distributed across two or more nodes within the distributed file system. Responsive to an access to the file prior to the timer reaching a first timer window threshold, the computer resets the timer. Responsive to the timer matching a first timer window threshold, the computer automatically reduces a number of replicas of the file within the distributed file system, wherein the probability that the file will be accessed prior to the first timer window threshold is greater than the probability that the file will be accessed after the first timer window threshold.

Abstract: An optic sensor system comprising N optic sensors, each of the N sensors operating with received input light and providing output light having a characteristic corresponding to a sensed parameter; a number, less than N+2, of devices wherein each of the devices operates as a light source and as a light detector such that one device can be used to transmit interrogation light to two of the sensors, with two other of the devices being used to receive output light from the interrogated sensors; and optic waveguide means for transmitting light between the sensors and the devices.

Abstract: A proximity detector apparatus that uses the Faraday Effect to detect position changes of a target. The proximity detector includes a permanent magnet having a magnetic field that changes as the target moves to or from a predetermined position. A self-referencing optical sensor is provided that detects the changed magnetic field. The optical sensor includes a magneto-optic material positioned near a node of the magnet. Means are provided to transmit polarized interrogation light along an optical path that includes the magneto-optic material. The optical path is bi-directionally addressed and is non-reciprocal. The optical sensor transduces the changed magnetic field into a modulation of the interrogation light's intensity. Means are provided to detect variations in the interrogation light intensity and to determine a ratio such as the difference over the sum ratio for two interrogation light samples that traveled the optic path in opposite directions.

Abstract: A proximity detector apparatus that uses the Faraday Effect to detect position changes of a target. The proximity detector includes a permanent magnet having a magnetic field that changes as the target moves to or from a predetermined position. A self-referencing optical sensor is provided that detects the changed magnetic field. The optical sensor includes a magneto-optic material positioned near a node of the magnet. Means are provided to transmit polarized interrogation light along an optical path that includes the magneto-optic material. The optical path is bi-directionally addressed and is non-reciprocal. The optical sensor transduces the changed magnetic field into a modulation of the interrogation light's intensity. Means are provided to detect variations in the interrogation light intensity and to determine a ratio such as the difference over the sum ratio for two interrogation light samples that traveled the optic path in opposite directions.

Abstract: A debris monitor apparatus and method and optical sensor apparatus and method that use the Faraday Effect to detect accumulation of debris on a magnetic probe. The probe contains a magnet and the optical sensor and is immersible in the fluid. As debris accumulates on the probe, the magnetic field changes. The optical sensor includes a magneto-optic material located within a portion of the changeable magnetic field, preferably near a node of the magnet. Means are provided to bi-directionally address the sensor magneto-optic material with linearly polarized light. Means are also provided to convert rotation of the light polarization angle into a modulation of the light's intensity. An electro-optic transducer converts the light intensity into electrical signals that indicate the quantity of debris accumulation on the probe, with a differentiated value of these signals with respect to time yielding rate of debris accumulation on the probe.

Abstract: A proximity detector apparatus that uses the Faraday Effect to detect position changes of a target. The proximity detector includes a permanent magnet having a magnetic field that changes as the target moves to or from a predetermined position. A self-referencing optical sensor is provided that detects the changed magnetic field. The optical sensor includes a magneto-optic material positioned near a node of the magnet. Means are provided to transmit polarized interrogation light along an optical path that includes the magneto-optic material. The optical path is bi-directionally addressed and is non-reciprocal. The optical sensor transduces the changed magnetic field into a modulation of the interrogation light's intensity. Means are provided to detect variations in the interrogation light intensity and to determine a ratio such as the difference over the sum ratio for two interrogation light samples that traveled the optic path in opposite directions.