Abstract: Either a backup BIOS or a main BIOS in a non-volatile memory is used to fully boot a computer system, depending on the validity of the main BIOS, successful prior booting using the main BIOS, or the validity of the CMOS settings. Unlike the boot block procedure, in either case, the computer system becomes fully operational. A count is made indicating the number of times booting is retried with the main BIOS. If a predetermined count value is reached, the main BIOS is invalid, or CMOS is invalid, then booting is completed using the backup BIOS. If the predetermined count value is not reached, a jump is made from the end of the BIOS validation code to an entry point in the main BIOS of the non-volatile memory to continue booting using the main BIOS. The backup BIOS is stored in a permanent protected portion of the non-volatile memory and the main BIOS is stored in a flashable portion of the non-volatile memory.

Abstract: A method for testing a computer bus using a bridge chip having a freeze-on-error option that enables a computer system's central processing unit (CPU) to recover and continue processing even when the computer bus is not functional. The testing method of the present invention remains transparent to a user and can be accomplished while performing standard diagnostics tests. In general, the present invention injects an input/output (I/O) error into a specific bus slot of the computer bus to test the functionality (such as the error recovery capability) of the bus. The present invention then recovers from the failure condition without having the computer system shutdown or stop working and without having to restart the computer system. More specifically, the method for testing a computer bus according to the present invention includes enabling the freeze-on-error option on the bridge chip, injecting an error into the specified computer bus slot and recovering from the injected error.

Abstract: An information processing apparatus having a plurality of CPUs has increased reliability. When one of storage devices suffers a fault, a corresponding control device indicates the fault to other control devices, so that all the control devices can recognize the fault. When either one of the CPUs has accessed the storage device, the control device indicates the occurrence of the fault to the CPU. Upon reception of the indication of the occurrence of the fault, the CPU changes the storage device for an active system, if necessary, according to predetermined rules. The same processing is performed when other CPUs have accessed the storage device. As a result, when all the CPUs have accessed the storage device, the setting up of the active system is completed.

Abstract: A method of and a device for implementing redundancy in a process control network using a pair of redundant devices, such as redundant I/O devices, communicatively connected to a segment of the bus in parallel to each other and in series between the controller and field devices on the segment. The redundant devices are assigned a virtual publishing address, which may be the unique address of one of the redundant devices, that is used in communicating over the bus. At all times, one of the redundant devices is operating in an active mode and communicating with the devices in process control network, and the other redundant device is operating in a backup mode wherein the redundant device maintains a communication connection with the devices and listens for messages transmitted by the devices and intended for the redundant devices, but does not respond to messages from the other devices until the device switches to the active mode.

Abstract: A disc drive includes a base and a disc rotatably attached to the base. A controller for a disc drive uses a system for mapping logical block addresses to actual location on a disc drive stores the number of skipped or defective sectors which occur prior to a target cylinder in a cylinder skip table. The system estimates a starting cylinder location for the selected logical block address. After estimating the cylinder location, a number of skipped defective sectors that have occurred prior to a cylinder start is determined. The starting location of the cylinder is slipped by this amount. A target track and associated head is also determined. Information in the track identification field is used to adjust the actual location on the track and to determine if a track seek to another track is needed.

Abstract: Data is multiplexed in a frame having a fixed bit length in a telecommunication system. The data is transmitted by transmitting a first transport channel comprising a first number of bits; transmitting first error detection bits associated with the first transport channel and comprising a second number of bits; transmitting a second transport channel comprising a third number of bits; transmitting a third transport channel comprising a fourth number of bits; and selectively transmitting a control channel comprising a fifth number of bits. The control channel is transmitted after the first error detection bits and before transmission of the third transport channel. Whenever the control channel is transmitted as part of the frame, a sum of the first, second, third, fourth and fifth number of bits equals the fixed bit length, but whenever the control channel is not transmitted as part of the frame, a sum of the first, second, third and fourth number of bits equals the fixed bit length.

Abstract: A method and system for employing fast, but easily corrupted mass storage for reliably backing up objects, such as files and databases. In a LUN-based mass storage device, a system or application may request and receive a lock on a particular LUN prior to storing a backup object on the LUN. The system or application may later request lock information for the LUN in order to decide whether or not the backup object can be reliably used for a restore operation. If the system or application continues to hold a lock on the LUN, then the backup object is reliable.

Abstract: In an Automatic Fault Management System which monitors components on multiple platforms and workstations, an Electronic Service Generator operates to sense error events and selects an appropriate Formatter unit to develop a report packet for a Remote Service Unit.

Abstract: A mirrored data storage system utilizes a first host device and a local storage device for primary data storage and a second host device and a remote storage device for mirrored, fail-over storage on behalf of client devices. At periodic intervals (called checkpoints), the first host device initiates data synchronization between itself and the two storage devices and issues checkpoint information to ensure that each device maintains information for a common stable storage state. The local storage device synchronizes its stored data and forwards the checkpoint information to the remote storage device. The remote storage device maintains a copy (called a snapshot) of the data at the common stable storage state. Given the snapshot and the checkpoint information, the remote storage device can restore itself to the common stable storage state in the event of a failure of the first host device and/or the local storage device.

Abstract: A diagnosis engine for diagnosing a device having a plurality of components receives test results of a set of tests on the device where at least one test has failed, and a model giving the coverage of the tests on the components of the device and information describing probabilistic dependencies between the tests. The diagnosis engine includes a specifier to specify a number N of components that may be simultaneously bad, N being an integer, and a computer to compute, within floating point computation errors, a likelihood that each of subsets of the components having size less than or equal to N are the bad components.

Abstract: Mechanisms are provided for preserving data wherein one or more nodes in a distributed computing system experiences an error. In one embodiment, when an error occurs, an error event is identified. Based on this error event, a set of identified execution units is suspended and a set of identified data is collected. All suspended execution units are then released, i.e., allowed to continue execution at the point where the units were suspended. The data collected during suspension is then used to diagnose the cause of the error.

Abstract: A backup apparatus and method suitable for protecting the data volume in a computer system function by acquiring a base state snapshot and a sequential series of data volume snapshots, the apparatus concurrently generating succedent and precedent lists of snapshot differences which are used to create succedent and precedent backups respectively. The data volume is restored by overwriting the base state data with data blocks identified in one or more succedent backups. File recovery is accomplished by overwriting data from a current snapshot with one or more precedent backups.

Abstract: An automatic fault management system can monitor multiple platforms in a digital network to sense software and hardware malfunctions. An Event Log stores the details of each malfunction and enables an electronic service requester generator to develop formatted packets of information for transmittal to a remote service center. Administrative and monitor screens are made available to control and view each packet sent out and its status of receipt and return acknowledgment data.

Abstract: A method, system, and apparatus for recovering system resources to provide a minimum system configuration in a data processing system is provided. In one embodiment, a firmware component within the data processing system, during initial program load, determines that a first resource has failed. The first resource is then deallocated. Responsive to a determination that deallocation of the resource has resulted in less than the minimum system configuration for operation of a data processing system, the firmware component determines which of a plurality of deallocated resources suffered from the least severe failure. The one of the plurality of deallocated resources that suffered from the least severe failure is then reallocated for use by the data processing system.

Abstract: A system and method for manufacturing disk drives, the disk drives having reliability attributes and manufacturing attributes, the manufacturing attributes comprising process or component manufacturing attributes is disclosed. The reliability attributes comprise measurements for predicting future reliability of the disk drives at the time of manufacture. The disk drives are prepared with a servo format. Each disk drive is connected to a test apparatus and then tuned to verify that each disk drive performs within expected limits. One or more technical screen tests are performed on all of the disk drives. A first sample set of the disk drives is selected automatically at a defined size using a randomizer. One or more extended tests are executed on the first sample set of disk drives to measure a margin magnitude for one or more of the reliability attributes. The margin magnitude is compared with a reference to detect a significant change.

Abstract: The present invention provides a method of testing a policy to detect problems and provide a mechanism for user feedback in advance of policy deployment in a policy-based network management system, so that network traffic will not be affected by errors in deployment.

Abstract: An integrated circuit verification method and system are disclosed. The method includes generating a test description comprising a set of test cases. The functional coverage achieved by the test description is then determined. The functional coverage achieved is then compared against previously achieved functional coverage and the test description is modified prior to simulation if the test description achieves no incremental functional coverage. In one embodiment, generating the test description comprises generating a test specification and providing the test specification to a test generator suitable for generating the test description. In one embodiment, the test description comprises a generic test description and the generic test description is formatted according to a project specification and simulation environment requirements. If the coverage achieved by the test description satisfies the test specification.

Abstract: A system and method for diagnosing and validating a machine with waveform data generated therefrom. Historical waveform data are obtained from machines having known faults along with corresponding actions for repairing the machines and are used to develop fault classification rules. The fault classification rules are stored in a diagnostic knowledge database. The database of classification rules are used to diagnose new waveform data from a machine having an unknown fault.

Abstract: A system and method for transferring data over a communications medium. A host is coupled to a device through a serial bus lacking error handling capabilities, such as an IEEE 1394 bus. The host may control the device by sending requests accessing its memory registers. The host generates a first request to the device to access a memory address location of the device, and which includes an address and status information indicating whether a prior request to the memory address location returned successfully. The device examines the status information to determine if it is a retry of a prior request, and if so, determines if the prior request completed successfully to the memory address location by comparing the address and data transfer size of the first request to those of the prior request. If identical, then the prior request completed successfully to the memory address location, and the request is ignored. Otherwise, the device retries the prior request.

Abstract: A redundant automation system including a set of redundant PLCs including of a pair of PLCs each equipped with two communication couplers. The first coupler in the first PLC is connected to the first coupler in the second PLC through a first Ethernet network and the second coupler in the first PLC is connected to the second coupler in the second PLC through a second Ethernet network, connecting them to at least one remote equipment. Each of the PLCs has a hardware address and an IP address, the set of redundant PLCs being accessible from outside by a single IP address assigned to a first normal PLC, and a switching mechanism assigns the address related to normal operation to the second PLC, the IP address of the standby operation being assigned to the first PLC.