Abstract: A storage cluster includes integrated cached disk arrays (ICDAs) and cluster interconnect such as a set of Fiber Channel links. Selected ICDAs include data storage disks collectively configured as cluster volumes. A switch network in each ICDA provides connections between the cluster interconnect and host interfaces, disk interfaces, and memory modules that may reside in the ICDA. Upon receiving a request, an ICDA determines whether the target disk resides in another ICDA, and if so forwards the request to the other ICDA via the cluster interconnect. The other ICDA services the request and returns a completion indication, which is forwarded to the host. Requests may also flow from the second ICDA to the first ICDA. The ICDAs may also include memory for data caching. The switch network preferably has a common interface to the different functional elements (host interfaces, disk interfaces, memory modules) for greater flexibility in configuring each ICDA.

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 method and apparatus for accessing storage from at least two different host computers features creating a first file having a first meta-data format and user data blocks in a mass storage medium using the first host computer and reading a logical to physical mapping of the user data blocks from the first file. A second file, having a second meta-data format, is created using a second host computer and the second file has blocks preallocated to be the same length as user data blocks of the first file. A logical to physical mapping of the preallocated user blocks is then obtained and the data blocks of the preallocated file are linked to the data blocks of the first file so that a reference to the preallocated blocks will provide an address at which the data requested can be read in the first file. In this manner, different meta-data blocks, corresponding to different filesystems, and/or operating systems, can be used in the respective first and second host computers.

Abstract: A distributed computer system includes a plurality of computer nodes, including conventional digital computer systems, mass storage subsystems, servers and the like, and a common event log. The common event log includes a plurality of storage locations for storing common event log entries. Each computer node performs processing operations in connection with a program, and generates, at selected points in its program, an event log entry including status information representing status of the computer node at the point at which the log entry was generated, the computer nodes storing the event log entries which they generate in the common event log contemporaneous with the generation thereof. As a result, the event log entries are stored in the common event log in the order in which the computer nodes reach the points in their respective programs.

Abstract: A method of managing a storage system which includes a local and remote systems is provided. Link services between the two subsystems are provided though the use of a task queue. The task queue resides in a global memory of the local storage system and receives requests from the various host controllers, device, and remote controllers connected to the local storage. The remote controllers of the local storage service the requests placed in the task queue to enable data transfer between the local and remote storage systems. The task queue may be a doubly linked list of records including forward and backward pointers in addition to the request data. A two level locking scheme is employed to prevent the addition of incompatible requests to the queue and to enable maximum parallelism in servicing requests in the queue. The first level of locking applies to the entire queue and is used when records are added to and deleted from the queue. The second level of locking applies to the individual queue records.

Abstract: A method and apparatus for providing an HTML applications development environment is disclosed. The applications development environment is used to develop large HTML based applications. The invention includes a preprocessor and associated preprocessor commands which are inserted into a source HTML file. The preprocessor reads the source file, evaluates the preprocessor commands, and makes the appropriate substitutions into an output HTML file.

Abstract: The invention relates to a method and apparatus for reordering, at a disk drive controller, a received sequence of read and write commands. The reordering can be system driven so that the system, when a command stalls, examines the command queue for another command to execute. Alternatively, the command queue itself can be reordered depending upon the expected time it takes for various commands to execute. Reordered commands can be flagged so that they cannot be reordered again. The resulting increase in throughput and efficiency occurs without reference to the particular disk drive or disk drive array configuration to which the controller is connected.

Abstract: A network file server includes a first set of data processors for receiving requests from clients, and a second set of data processors for accessing read-write file systems. A respective data processor in the second set is assigned to each file system for exclusive management of locks on the file system. The file server can detect failure of a failed data processor and automatically recover from the failure. When a failure of a data processor in the first set is detected, a spare data processor is programmed with the logical and physical network addresses of the failed data processor so that the spare data processor assumes the network identity of the failed data processor. When a failure of a data processor in the second set is detected, responsibility for management of the locks on each file system managed by the failed data processor is transferred to an operational data processor.

Abstract: A method and apparatus for providing very large logical volumes (Meta Device) in a storage system is provided. The storage system includes host controllers and disk controllers which communicate through a shared memory. I/O requests are received by the host controller and placed into request queues. The request queues are associated with logical devices. A number of request queues in the host controller are concatenated together to produce the larger logical volume. The large logical volume appears to the host as a single addressable logical unit. I/O requests to the large logical volume are analyzed by the host controller to determine which logical devices are actually needed to service the request. The host controller then makes the appropriate queue entries. Processing of the requests then occurs in the same fashion as if the request had been to a non-Meta Device. This allows the disk controllers and memory to operate without modification.

Abstract: A semiconductor interconnect structure which includes a semiconductor substrate having a bottom surface. The printed circuit board also has a plurality of solder wettable pads disposed on the top surface of the printed circuit board. The printed circuit board and the semiconductor substrate are both comprised of material taken from the same group of materials. The interconnect structure also includes a plurality of balls formed of a first solder alloy disposed on the bottom surface of the semiconductor substrate and projecting downwardly therefrom. Each one of the plurality of balls are sized to support the weight of the semiconductor substrate. The interconnect structure also includes a plurality of solder joints formed of a second solder alloy connecting the plurality of balls to the corresponding plurality of wettable pads on the printed circuit board.

Abstract: A network file server includes a first set of data processors for receiving requests from clients, and a second set of data processors for accessing read-write file systems. A respective data processor in the second set is assigned to each file system for exclusive management of read and write locks on the file system. Each data processor in the first set can authorize access to file systems directly accessed by more than one data processor in the second set. Processing of a request for access that is authorized is continued by the data processor that is assigned to manage the locks on the file system to be accessed. The exclusivity of lock management eliminates cache coherency problems, and dynamic load balancing can be used to prevent the lock management from becoming a bottleneck to performance. A preferred embodiment includes a cached disk storage subsystem linked to data mover computers.

Abstract: A method of dynamically changing a storage system from a RAID configuration to a mirror configuration is provided. The change occurs when a device begins to fail or fails completely. Data from the logical volumes of the failed device is written to corresponding parity volumes within the RAID group. In addition, data from all logical data volumes is copied to spare devices. Once all the data is copied, the system operates in a mirrored mode. A mirrored mode includes writing data to both and active and backup volume for each write transaction. When the failed device is replaced the data and parity volumes are restored. Once restored, the spare devices are returned to inactive status.

Abstract: A shared resource lock mechanism is provided which enables processors in a mullet-processor environment which each share common resources to obtain locks on those resources using a read modify write type transaction which does not at any point in time require the locking of a bus or a memory which contains the lock records used to lock the particular resources.

Abstract: A cache management system and method monitors and controls the contents of cache memory coupled to at least one longer term data storage device. Cache memory is organized into at least first and second sections, the first section for storing data waiting to be written to a longer term data storage device and the second section for storing data elements which have been written to the longer term data storage device. The cache management system and method monitors data elements awaiting writing to the longer term data storage device.

Abstract: An apparatus for capturing data transmitted over of a plurality of bidirectional communication buses is provided. The apparatus comprises a plurality of trace engines, each trace engine having a trace analyzer and a central processing unit connected together with a bus. Each one of the trace engines is connected to another trace engine, so that all of the trace analyzers within the trace engines are synchronized to a common clock. The synchronization to a single common clock allows all of the data captured by the plurality of trace engines to be analyzed or used together.

Abstract: A mass storage system having at least one input/output controllers in connection with a host computer is disclosed. The mass storage system also includes mirrored storage devices in connection with the input/output controllers through a global cache memory. Each mirrored pair of storage devices is assigned a common logical volume address, but is looked upon by the host computer as a single entity. The cache memory includes dynamically allocable cache slots, which correspond to each common logical volume address. When the host wishes to write data to a pair of mirrored storage devices, the contents of first write operation are written into the appropriate cache slot. However, when a second write operation is received by the input/output controllers, a determination is made as to whether the contents of the second write operation are already in the cache memory.

Abstract: A method and apparatus for managing a network attached storage system is presented which includes a web based user interface. The interface allows for the execution of many different commands on several different storage system attributes without loss of context between command execution. The interface is HTML based and provides dynamic construction of Javascript object lists based on a database read by a CGI program executing on an HTTP server. The interface eliminates the hierarchical structure of menu navigation associated with other interfaces.

Abstract: A method of providing error to a host computer coupled to a storage system is provided. The method includes modifying a command in the storage system/computer communications protocol. The command, when received by a controller within the storage system is interpreted as being a modified command. The controller is responsive to the modified command for reading error information from its stored location within the storage system. The error information is then returned to the requesting host computer. Thus, previously unavailable error information is made available host computers coupled to the storage system without the need to add commands to the standard communications protocol.

Abstract: A method of managing a storage system is provided which allows each host of connected to a storage system supporting multiple hosts to view the identification information assigned to the storage devices by the respective hosts. The method includes providing a command which allows a host to write identification information to an area on the disk drives controlled by the host which was previously reserved for use by the storage system. In addition to writing the data to the physical storage device, execution of the command also causes the identification information to be written to an area in global memory which holds information about each of the storage devices in the storage system. Since the information is stored in a global memory, each host my access the information. Using a second command provided, any host may read the information in global memory and thus learn the identification assigned by other hosts.