Abstract: A technique is disclosed for reprovisioning an interconnect fabric design for interconnecting a plurality of network nodes. A design for the interconnect fabric specifies an arrangement of elements of the fabric and flow requirements among the network nodes. The invention programmatically reprovisions the design. This may include determining whether the flow requirements are satisfied by the design and whether the design violates constraints on the elements, such as bandwidth capacity and number of available ports. If the design does not satisfy the flow requirements, then the design is modified until the flow requirements are satisfied. Modifications are performed systematically by first attempting those that are least disruptive to the design and, then, attempting modifications that are increasingly more disruptive. As a result, the design is efficiently and cost-effectively reprovisioned to meet the flow the requirements.

Abstract: The invention relates to an apparatus for finding a parked vehicle again. According to the invention, a portable unit is provided with a pressure sensor whose signals can be evaluated by an evaluation and control unit in order to determine the current air pressure, with the evaluation and control unit evaluating the determined air pressure in order to determine altitude, and storing a first air pressure value as a reference value at a predeterminable first time, which reference value represents an instantaneous altitude of a geographic position of the parked vehicle, with the evaluation and control unit estimating a height difference between a current geographic position of the portable unit and the geographic position of the parked vehicle at a second time, and/or continuously from a pressure difference between the determined current air pressure value and the reference value.

Abstract: A sequence of write transactions are performed at a first storage facility. The write transactions are arranged into a sequence of send batches forwarded to a second storage facility where the write transactions are arranged into a sequence of receive batches. At the first storage facility or at the second storage facility, a first write transaction is replaced with a second write transaction wherein the second write transaction overwrites data written by the first write transaction. A receive batch includes all write transactions between the first write transaction and the second write transaction. The write transactions are applied to a redundant data copy at the second storage facility in which all of the write transactions for the receive batch are applied as a whole to the redundant copy of the data.

Abstract: An embodiment of a computer implemented method of providing a design of a system receives a relative performance specification for the system. A particular system design is returned that is expected to perform at about the relative performance specification.

Abstract: A technique and user interface for the assignment of computer system resources and, particularly, for the assignment of storage system resources. The invention allows a user to make design selections through a user interface and, then, automatically provides an indication to the user as the effect of the selections. For example, various performance parameters for each of several applications may be displayed graphically as a chart. In response to the user adjusting a parameter for one application, the invention determines what effect this change will have on the other displayed parameters. A design for the computer system is developed. Levels of performance parameters for the design are predicted. The predicted levels of performance parameters are compared to the desired levels of performance parameters. When the predicted levels are lower than the desired levels, the design is modified. The design may be modified by reducing the desired levels of performance parameters based on utility functions.

Abstract: A technique for providing reliability to an interconnect fabric for communication among a set of nodes. The technique may be used to efficiently and programmatically produce a cost-effective interconnect fabric having a degree of reliability over a range of design problems. In one aspect, ports associated with each node are partitioned into a first set of ports and a second set of ports. A primary interconnect fabric is formed among the first set of ports in response to a set of flow requirements and a backup interconnect fabric is formed among the second set of ports. The backup interconnect fabric carries a portion of communications carried by the primary fabric so as to protect against a failure of an element in the primary fabric.

Abstract: An electrochemical cell for a medium-temperature thermal battery includes an electrolyte having a melting point between 75° C. and 200° C., a thermal decomposition temperature above 300° C., and consisting essentially of at least one organic salt. The electrolyte is ionically conductive at temperatures from the melting point to at least the thermal decomposition temperature, generating a voltage across a cathode and an anode of the cell. The electrolyte is ionically non-conductive at temperatures below the melting point.

Abstract: A technique of workload characterization for a computer system. Records of activity in the system are generated and identified as corresponding to each of a plurality of selected time periods. The records of activity for each selected time period are processed to form a characterization of the activity within each corresponding time period. Further, whether little or no activity occurs during a time period can be indicated by a binary representation. Periods of simultaneous activity of processes can then be determined by applying simple logical operations to the binary representations. Resources of the system may be reallocated based on the characterizations of the activity.

Abstract: The present invention provides a system for and method of retrieval-based data redundancy. In an embodiment, a first write operation is performed on a data object at a first storage subsystem to form a first version of the data object, the data object being included among a plurality of data objects of primary data. An identification of the data object is sent to a second storage subsystem. Using the identification of the data object received by the second storage subsystem the data object is retrieved from the first storage subsystem. The retrieved data object is applied to a secondary data at the secondary storage subsystem, the secondary data being redundant of the primary data.

Abstract: According to one embodiment, a method comprises intercepting, at an interposition agent, requests for accessing a data storage device. The method further comprises determining, by the interposition agent, at least one of the requests to impact, and selectively simulating, by the interposition agent, a fault for the selected at least one of the requests. According to another embodiment, a system comprises at least one data storage device, and at least one requester operable to request access to the at least one data storage device. The system further comprises at least one interposition agent communicatively interposed between the requestor(s) and the data storage device(s) to intercept requests for access from the requestor(s) to the data storage device(s), wherein the interposition agent is operable to selectively determine ones of the intercepted requests to impact and selectively simulate a fault for the selected at least one of the requests.

Abstract: Methods and apparatus for obtaining consistency of redundant data after a failover event. In one aspect, a redundant data storage system has a first data storage facility that initially acts as a primary facility for storage requests and a second data storage facility that initially acts as a secondary facility for the storage requests. The second data storage facility is conditioned to assume the role of the primary facility in response to a failover event. The first data storage facility is conditioned to assume the role of the secondary facility, which includes sending a copy of data committed at the second data storage facility to the first data storage facility. The copy of data includes a version of data committed at the second storage facility.

Abstract: Data is migrated by moving a set of the data in a data storage system of a computer system. The method includes monitoring a performance of at least one executing application while moving the data in the data storage system. A change in the rate of moving is calculated in response to the monitored performance of the executing application. The rate of moving is modified in accordance with the calculated change.

Abstract: Techniques for performing data redundancy operations in a distributed manner. A primary data storage facility stores a primary copy of data and a secondary facility stores data that is redundant of the primary copy of the data. The primary facility includes a first redundancy appliance that receives a first sequence of write requests and stores data for the first sequence of write requests in mass storage associated with the first redundancy appliance. A second redundancy appliance receives a second sequence of write requests and stores data for the second sequence of write requests in mass storage associated with the second redundancy appliance. Thus, a workload is shared among the first and second redundancy appliances by dividing the workload into the first and second sequences of write requests, where each sequence is handled by a different redundancy appliance.

Abstract: Techniques for performing data redundancy operations in a fault-tolerant manner. In one aspect, a primary data storage facility stores a primary copy of data and a secondary facility stores data that is redundant of the primary copy of the data. The primary facility includes a first redundancy appliance that receives a sequence of write requests and stores data for the sequence of write requests in storage associated with the primary storage facility. A second redundancy appliance shadows the first redundancy appliance and assumes the role of the first redundancy appliance in the event of a fault at the first redundancy appliance. In this way, fault tolerance is increased by the presence of the second, shadow appliance.

Abstract: A technique for adaptive batching for asynchronous data redundancy. A sequence of write transactions are adaptively arranged into a sequence of send batches at the first storage facility. The transactions are received at a second storage facility and applied to a redundant data copy at the second storage facility. The second storage facility may arrange the write transactions according to a sequence of receive batches. The batch sizes may be adaptively adjusted or completed. The batch sizes or adaptive completion of the batches may be based on, for example, availability of a communication medium between the first storage facility and the second storage facility. Each send batch may be forwarded to the second storage facility upon completion.

Abstract: A state machine and system for redundantly backing up data. A first storage facility is controlled by a first state machine having a finite number of states, each state having a set of allowed operations. The first state machine includes at least one state for controlling the first storage facility to operate as a primary storage facility for storing and updating a primary copy of the data. A second storage facility is controlled by a second state-machine that has least one state for controlling the second storage facility to operate as a secondary storage facility for storing redundant data. The second state machine also has at least one state for controlling the second storage facility to operate as the primary storage facility. The second storage facility assumes the role of primary in response to a fault at the first storage facility or based on the origin of request traffic.

Abstract: An embodiment of a method of cooperative caching for a distributed storage system begins with a step of requesting data from storage devices which hold the data. The method continues with a step of receiving any cached blocks and expected response times for providing non-cached blocks from the storage devices. The method concludes with a step of requesting a sufficient number of the non-cached blocks from one or more particular storage devices which provides an expectation of optimal performance.

Abstract: A technique for designing an interconnect fabric for communication between a set of source nodes and a set of terminal nodes. A design for an interconnect fabric is obtained having an interconnect device layer. The layer is adjacent to either the set of source nodes or the set of terminal nodes. Flow sets that traverse the layer of interconnect devices are identified. A pair of the flow sets are merged thereby alleviating at least one port violation. The technique may be implemented programmatically by a design tool.

Abstract: A method of managing storage of a file in a network environment includes storing, in a central repository, tracking information of copies of the file on storage server systems in the network environment. The tracking information in the central repository is used to identify plural copies of the file. Information pertaining to the plural copies of the file is communicated to a client system. One or more requests responsive to the information pertaining to the plural copies of the file are received from the client system to delete one or more of the copies of the file.

Abstract: In a method of modeling a target system, a data structure is populated with points, where each point includes at least one target value associated with at least one system parameter value of the target system. The data structure is searched with at least one inquiry parameter value. A return value is interpolated for at least one inquiry parameter value based on the points.