Abstract: A system comprising a mass storage subsystem, as a master device and backup subsystem, as a slave device, the slave device transferring data items to the master device during a restore operation. Each data item to be restored is identified by a data item identifier. The master device initially provides the slave device with a list of data item identifiers and the slave device receives the data item identifier list from the master device and order the data item identifiers thereon in an optimal order for transfer to the master device, the ordering based on the ordering of the data items on storage media on which they are stored. The master device, in each of a plurality of iterations, receives from the slave device data item identifiers identifying a data item transferred during a previous iteration and a data item to be transferred during the current iteration and requests the slave device to transfer the data item to be transferred.

Abstract: A storage controller has at least one physical data port for a data network including host processors. The storage controller is programmed to provide a plurality of virtual ports for access to storage, and a virtual switch for routing storage access requests from the physical port to the virtual ports. The virtual ports and the virtual switch are defined by software. The virtual ports appear to the hosts as physical ports in the data network. For example, in a Fiber-Channel network, the virtual ports have World Wide Names (WWNs) and are assigned temporary addresses (S_Ds), and the virtual switch provides a name server identifying the WWNs and S_IDs of the virtual ports. For convenient partitioning of storage among host processors, one or more virtual ports are assigned to each host, and a set of storage volumes are made accessible from each virtual port. A host can access storage at a virtual port only if the virtual port has been assigned to the host.

Abstract: An apparatus and method for disk mapping and data retrieval includes a data storage medium on which has been stored a plurality of data records. Each record includes at least a record identification portion, for uniquely identifying each record from among the plurality of data records. The apparatus builds a record locator table in high speed semiconductor memory which comprises the unique record identifiers for the records on the storage medium as well as a record locator index generated by the apparatus, which indicates the address of the data record on the storage medium. Data retrieval is facilitated by first searching the record locator table in high speed semiconductor memory for a requested data record. Utilizing the record locator index associated with the requested data record, the system directly H: accesses the requested data record on the storage medium thereby minimizing storage medium search time.

Abstract: A data storage system wherein a host computer is coupled to a bank of disk drives through a system interface. The system interface includes a memory having a high address memory section and a low address memory section. A plurality of directors controls data transfer between the host computer and the bank of disk drives as such data passes through the memory. A pair of high address busses, comprising a plurality of bus high address bus segments, is in communication with the high address memory section and a pair of low address busses, comprising a plurality of low address bus segments, is in communication with the low address memory section. Each one of the directors is in communication with one of the pair of high address busses and one of the pair of low address busses.

Abstract: A plurality of state machines arranged into three functional units, an Upper Machine, Middle Machine and a Lower Machine facilitate movement of user data between a buffer memory and a Global Memory (GM) in a data transfer interface. The Middle Machine controls all data movement to and from the GM. Although not directly in the data path, it is responsible for coordinating control between elements that comprise data transfer channels. The Middle Machine is interconnected to and provides control and coordination between the Upper and Lower sides of the buffer memory. The Lower Machine connects to a data assembly mechanism of each pipe. The Upper Machine connects to the backplane, which in turn connects to Global Memory. The actual data transfers between the buffer memory and GM are controlled by the Upper Machine, and transfers between the buffer memory and the data assembly mechanism are controlled by the Lower Machine.

Abstract: Featured is a method for reducing the contention of the highly contended global lock(s) of an operating system, hereinafter dispatcher lock(s) that protects all dispatching structures. Such a method reduces the need for acquiring the global lock for many event notification tasks by introducing local locks for event notifications that occur frequently among well defined, or consistent dispatcher objects. For these frequently occurring event notifications a subset of the dispatching structure is locked thereby providing mutual exclusivity for the subset and allowing concurrent dispatching for one or more of other data structure subsets. The method also includes acquiring one or more local locks where the level of protection of the data structure requires locking of a plurality or more of data structures to provide mutual exclusivity.

Abstract: Transmitting data from a source to a destination, includes receiving the data from the source and providing the data to the destination using a network, where the data is acknowledged to the source as being successfully received at the destination prior to all of the data being provided to the network. The source may be a primary storage device. The destination may be a secondary storage device. The data may be provided from the source in a first format and may be provided to the network in a second format that is different from the first format where the first format may be RDF and the second format may be TCP/IP or UDP. The destination may receive the data in a first format different from a second format used to transmit the data over the network. The first format may be RDF and the second format may be TCP/IP or UDP.

Abstract: A power conversion circuit for converting alternating current power to regulated direct current power by a power factor correction circuit having an integral bridge function providing reduced power consumption. A switching power conversion circuit provides direct current power to a load from an alternating current power source by providing current to an energy storage capacitor connected across the load from each of a first switching boost converter circuit and a second switching boost converter circuit operating alternately during corresponding polarity half cycles of the alternating current power source. The first and second switching boost converter circuits each include alternating current inputs connected inversely with respect to each other to first and second terminals of an alternating current power source and current outputs connected in parallel across an energy storage capacitor for storing current from the first and second boost converter circuits and providing direct current power to a load.

Abstract: A method and apparatus is provided for detecting airborne particles in an electronic enclosure. The electronic enclosure may be used to house one or more electronic devices or components of an electronic system, such as a computer or data storage system. A particle detection system is provided to monitor the air within the enclosure and to generate an alarm signal in response to detection of a threshold level of airborne particles within the enclosure that is indicative of an operational anomaly associated with at least one of the electronic devices or components. In response to the alarm signal, the electronic devices housed within the enclosure may be automatically shut down to reduce potential damage to at least the devices housed within the enclosure. The detection system is particularly suited for detecting the presence of smoke within an electronic enclosure, such as may be generated during a combustion event by overheated or electrically shorted electronic components.

Abstract: A storage system has a storage controller connected to a plurality of storage devices. The described system and method transfer physical data from a first storage device to a second storage device. The method does not involve a host computer in the physical data transfer thereby saving both computer CPU time and system bandwidth. The method receives an internal copy command from a commanding processor (the host) over a controller input path, reads at least one block of data, in data block format, from the first storage device, stores the requested data in a volatile memory in the controller, and sets a state of the pending stored data as a write pending state. The controller then destages the write pending memory stored data to the second storage device.

Abstract: A busy disk evaluation system includes a busy disk evaluation module and a control module. The busy disk evaluation module is configured to perform a busy disk evaluation operation in which it processes access request statistics relating to access requests directed to a server, the server including a plurality of disk storage units, respective access requests requesting access to respective ones of the disk storage units, to identify which, if any of the disk storage units is busy. The busy disk evaluation module is configured to determine whether a disk storage unit is busy in relation to a ratio between the number of access requests requesting access to the disk storage unit per unit time exceeds a selected access request per unit time threshold in relation to a total number of access requests and a selected ratio threshold. The control module is configured to control the busy disk evaluation module.

Abstract: Load balancing of activities on physical disk storage devices is accomplished by monitoring reading and writing operations to blocks of contiguous storage locations on the physical disk storage devices. Statistics accumulated over an interval are then used to obtain access activity values for each block and each physical disk drive. A method is disclosed for efficiently generating disk access time based upon these statistics.

Abstract: A bracket can selectively engage and disengage with a base in order to selectively secure and release a user station (e.g., a laptop computer configured to interface with a computer system) for access by a user (e.g., a system administrator). The use of the bracket enables a user station assembly to store the user station within a computer device cabinet in a compact manner, and subsequently unfold the user station assembly from the computer device cabinet for convenient access. In one arrangement, a user station assembly, includes a base, a support frame and a bracket which is pivotably attached to the support frame.

Abstract: There is disclosed an improved method for manufacturing printed circuit boards which solves the problem of immersion bath contaminants being plated-out onto electrically-conductive, circuit functional pads, (board-features) by introducing into the bath system a mechanism for attracting those contaminants to non-functional “micro-thieves” which are electrically-conductive, non-circuit-functional pads having substantially smaller dimensions than those of the smallest board-feature, thereby taking advantage of previously unknown immersion bath uncontrolled strike phenomena, whereby the contaminants are directed to the micro-thieves and away from the board-features. Application of the micro-thieves in the immersion bath environment also produces plated features, of both finer and larger geometries, having flatter surfaces and a more uniform plated thickness for all features on the printed circuit board, than previously obtained.

Abstract: A performance prediction generating system is disclosed for predicting a change in performance in connection with a server, the server having a plurality of disk storage units each for storing information, in relation to reallocating files as between two of the disk storage units. The performance prediction generating system comprises a file selector module and an access request processing module. The file selector module is configured to select a file on each of two of the disk storage units for reallocation therebetween.

Abstract: Mirrored data is contained in a first data storage device array and also in a second data storage device array. However, devices in the first array are not simply mirrors of devices in the second array. Instead, each data storage device in the second array contains a respective share of the mirrored data contained in each data storage device in the first array, and each data storage device in the first array contains a respective share of the mirrored data contained in each data storage device in the second array. Therefore, when a data storage device in one array fails, the failure load is spread over the data storage devices of the other array. For disk storage devices, the mirrored data can be arranged in the first and second arrays so that the mirrored data is contained at the same disk track radius in both arrays in order to equalize seek time for write access or sequential read access to both arrays.

Abstract: The invention relates to a data processing system and method wherein a data processing system is connected to at least two busses, each of which is connected to a memory system. Controllers connected to one of the buses monitor the write operations at each other bus. The monitoring controllers are each connected to less then all of the lines of the “other bus” and continuously update their cache memories to reflect and maintain the integrity of the data in the cache memory.

Abstract: A data storage system includes a plurality of control/data buses. A memory section is coupled to the plurality of control/data buses. The memory section includes a memory and a plurality of control logic sections interconnected through an arbitration bus. Each one of the control logic sections is coupled between a corresponding one of the control/data buses and the memory. Each one of such control logic sections includes a control logic for controlling transfer of data between the memory and the one of the plurality of control/data buses coupled to said one of the logic sections. The control logic is adapted to produce a control/data bus request for the one of the control/data buses coupled thereto and is adapted to effect the transfer in response to a control/data bus grant fed to the control logic. Each one of the control logic sections also includes a bus arbitration section coupled to the arbitration bus.

Abstract: A computer program product is used with a programmable device to provide a data item reconstruction element for reconstructing information stored on a back-up information storage subsystem associated with at least one protected volume. The back-up information storage subsystem includes a plurality of storage media, each associated with one of a plurality of sets, the information associated with the protected volume being stored on storage media associated with one of the sets. The data item reconstruction element during the reconstruction operation retrieves in parallel information from a plurality of the storage media associated with the one of the sets on which information associated with the at least one protected volume is stored, to obtain the information which is associated with the protected volume.

Abstract: Method and apparatus for generating partial backups of logical objects in a computer storage system are disclosed. Changed data blocks are identified and stored as differential abstract block sets. The differential abstract block set may include data blocks in any order and metadata identifying the relative position of the data block in the logical object. The invention includes methods for formatting updated backups using the differential backups.