Abstract: A method and system for updating status information in a persistent storage. The method comprises the steps of defining a table in persistent storage (NVS) for holding information about changes to the status information; and when that status information is changed, making an entry in the table to record the changed information. A task is initialized to update the information on the disk drive. This updating is done by (i) checking the table to determine if any changes have been recorded in the persistent storage, and (ii) if any changes have been recorded in the persistent storage, then copying the status information from the persistent storage to the disk drive.

Abstract: The present invention is a system and method for recovering from memory failures in computer systems. The method of the present invention includes the steps of: identifying a predetermined instruction sequence; monitoring for memory access errors in response to the request; logging a memory access error in an error logging register; polling the register for any logged memory access error during execution of the instruction sequence; and raising exceptions, if the memory access error is logged. Within the system of the present invention, memory access errors are stored in an error logging register, machine check abort handles are masked, and memory controllers are under full control of the software so that memory access errors can be intercepted and responded to without necessitating a system reboot or application restart. The present invention is particularly applicable to O/S code which can not otherwise recover from memory errors except by rebooting.

Abstract: A method, apparatus, and computer implemented instructions for reporting errors to a plurality of partitions. Responsive to detecting an error log, an error type for the error log is identified. If the error log is identified as a regional error log, an identification of each partition to receive the error log is made. Then, the error log is reported to each partition that has been identified to receive the error log.

Abstract: A system and method is provided for using a first data channel to pass working data and a second data channel to pass error correction information. For example, this second data channel may be defined along a redundant data path. For example, this error correction information may be forwarded error correction (FEC) information such as Hamming code information or any other type of error correction information. Use of the redundant path to forward FEC information provides several advantages: 1) the FEC information can be used to correct bit errors that occur within the system, making the system high-quality and more reliable and 2) use of the protected path provides an efficient method to constantly monitor the quality of both the working and redundant path. Monitoring is accomplished by using the FEC information on the redundant path in conjunction with the information on the working path to accurately count the number of errors that occur on the working and redundant paths.

Abstract: Hardware errors are stored in an error buffer for processing by one or more system partitions within a computer system. When errors are first placed in the buffer, an Already Reported Flag (ARF) is initialized to indicate that the error has not yet been reported to any of the system partitions. When one of the system partitions receives the corresponding error information by running a diagnostics routine, the ARF is set indicating that the error has been reported to at least one system partition. The system partition, in turn, uses the ARF information to determine how to handle the corresponding error. In an environment using a remote hardware service provider, the ARF determines whether to transmit the error information to the service provider. In environments without remote service providers, the ARF information is used to highlight newly reported errors to the user.

Abstract: A method of and apparatus for computer hard disk drive (HDD) protection and recovery. The apparatus includes a HDD controller board and a back-up HDD, both installed in a computer system having a working HDD. The apparatus utilizes hardware switches electrically coupled to the controller board, including a HDD selection switch and a copy command button. During normal operations, the switch remains switched to the working HDD, and as a result, the back-up HDD is switched off and remains transparent to the computer system and therefore protected from software viruses and other intrusions. The method includes a first-time image back-up process. When there is a failure of the working HDD, the back-up HDD can be instantly used as a normal HDD by switching the switch to the back-up HDD, so the computer system can be up and running without any interruption.

Abstract: A method for a computer repairing itself to an operational status at any time during operation, the method comprising the computer-executed steps of: booting from a first hard disk drive boot device disposed within a main computer hardware box of the computer; then, in response to a signal indicating a need for repair of the computer during the booting or during any operating state, booting from a second hard disk drive boot device also disposed within the main computer hardware box of the computer prior to the signal indicating a need for repair; and then repairing software on the first hard disk drive while booted from the second hard disk drive boot device and selectively either: (i) maintaining operation of the computer from the second boot device to restore operational status of the computer during repairing of the software on the first hard disk device, or (ii) changing to operation of the computer from the second boot device to the first boot device to restore operational status of the computer.

Abstract: A method, apparatus, and computer instructions for reporting errors occurring in a data processing system. Responsive to an error occurring in a host bridge in the data processing system, a determination is made as to whether a device required for generating an error report is located below the host bridge. Responsive to the device required for generating an error report being located below a host bridge, the host bridge is isolated from other portions of the data processing system, wherein only a processor analyzing the error is able to access the host bridge. An error reporting process is performed. The error reporting process is able to access the host bridge and the device.

Abstract: A router stores core file into a local flash memory after detecting a shutdown event. In order to increase the amount of core file data that can be stored, the core file is first compressed before being downloaded into the local flash memory. Because the flash memory is local, the network device is not required to dump the core file over an external network to an external network server. Thus, network interface elements in the network device do not have to be functional in order for the core dump to be successful. During the shutdown routine, interrupts are disabled for all processing elements that are not needed to perform the core download. The core dump is therefore faster and more reliable and allows more effective system debugging than present core download procedures.

Abstract: A method and system allows multiple compute elements to independently read and clear error register logs, discard invalid data and ensure that a user receives information stored in error log registers. Error log registers are not cleared until its information is successfully retrieved by a compute element. A counter maintains a count of errors for which detailed error information has been lost.

Abstract: A method and a device for storing a computer program in a program memory of a control unit. The computer program is stored according to predefinable rules in specific memory areas of the program memory. To recognize an erroneous jump into an unused memory area of the program memory, in which the computer program is not stored, as rapidly as possible and to prevent the control unit from being in an irregular state, selectable information, through which the control unit is transferred into a defined state, is stored in the unused memory areas of the program memory, in which the computer program is not stored.

Abstract: A computer processor includes a replay system to replay instructions which have not executed properly and a first event pipeline coupled to the replay system to process instructions including any replayed instructions. A second event pipeline is provided to perform additional processing on an instruction. The second event pipeline has an ability to detect one or more faults occurring therein. The processor also includes a synchronization circuit coupled between the first event pipeline and the second event pipeline to synchronize faults occurring in the second event pipeline to matching instruction entries in the first event pipeline.

Abstract: A method includes steps of (A) detecting an activation of a user input that indicates that the system, or a program executed by the system, has become non-responsive to a user; (B) determining an identification of any currently open files and programs with which currently open files are associated; (C) determining an identification of those programs that are normally not in a non-responsive state; and (D) saving those currently open files that are associated with programs that are identified as being not normally in the non-responsive state. A next step notifies the user that any currently open files that are associated with programs identified as being not normally in the non-responsive state have been saved. In a further step the user may restart the digital data processing system, and retrieve at least one of the saved files. The step of detecting can be executed in response to the user manually activating a switch or by the user activating one or more keyboard keys.

Abstract: The technique disclosed herein provides for simultaneously checkpointing all of the processes in a specified process group or family at the application level, and restoring those processes at a later time, optionally on a different machine, with the parent-child relationships restored intact. File descriptors that are shared among the processes at checkpoint time are restored to the family of processes such that the file descriptors are shared just as they were at the time of taking the checkpoint.

Abstract: A method, apparatus, and computer instructions for managing error logs. A request is received from a partition within a plurality of partitions in the logical partitioned data processing system to access error information. A determination is made as to whether the error information is located in a buffer. The error information is retrieved from a non-volatile memory in response to the error information being absent in the buffer. The retrieved error information retrieved from the non-volatile memory is stored in the buffer. This error information is stored in the buffer only for a selected period of time. After that period of time, this error information is deleted or removed from the buffer. In this manner, outdated error information is not returned to the plurality of partitions.

Abstract: This invention provides methods and apparatus which provide a solution to the problem of server load balancing. Log files are collected from each server within a server cluster. The log files are analysed by the monitoring process to find file relations. The analysis uses a window to search for requests such that a file relation is established. Other techniques are described to establish file relations. Based on file relations files are merged into groups such that these groups of files can be distributed to N servers within a server cluster. The file merging process continues until there are N groups corresponding to the N servers. The files for each group are either distributed to each server, or all files are distributed to all servers and each server activates only the subset which comprises the group of files for that server.

Abstract: The present invention is directed to a method of recovering a write ahead log after an interruption. In a first aspect of the present invention, a method of writing a log entry of a write ahead log may include initiating a log write to a write ahead log, the write ahead log having a first sector, and a second sector, wherein the first sector is followed by the second sector. A log entry including a sequence number is written to the second sector. Then, the log entry including the sequence number is written to the first sector.

Abstract: The present invention relates to a method and system for efficiently identifying errant processes in a computer system using an operating system (OS) error recovery method that identifies if the error caused by the errant process can be recovered and, if so, can recover from the error. The method and system of the present invention operates after standard Error Correcting Code (ECC) and parity check bit methods and systems are unsuccessful in recovering from the error In accordance with an embodiment of the present invention, the method and system includes detecting an error during instruction execution, storing a physical address of an errant process that caused the error, and storing an execution instruction pointer (IP) in an interruption instruction pointer (IIP).

Abstract: A data backup system for use with a server running a storage application that writes and reads data blocks. The system includes a self archiving log structured volume for copying blocks from an active volume while the application is running without contending with the application for access to data blocks. The volume records the result of every write event in a new location in primary storage, forming a chronological log of the state changes the volume undergoes. The volume records in the log the points in time (synch events) when the blocks of the volume are in a consistent state with respect to the application. The system further includes backing storage to store the archived blocks and synch events of the volume. The volume migrates inactive segments of its log to the backing storage and ensures that a volume can be reconstructed from a fixed number of log segments.

Abstract: A method and apparatus for merging log data for recovering one or more database data sets to any point-in-time in a single pass of log data sets. Using disaster recovery technology, the invention may be implemented to provide a method to reduce the time that a broken database is unavailable by processing recovery input data in parallel and recovering multiple database data sets, including areas, simultaneously. The invention reduces operational complexity and resource constraints experienced by IMS customers trying to recover database data sets especially in a data sharing environment. The invention simplifies the recovery process by eliminating both the need for change accumulation and the need to run separate recovery jobs for each database data set requiring recovery, thereby reducing the impact of recovery on system resources.

Abstract: A system and method are disclosed for aiding a field engineer in the field such as at a remote service facility in analyzing a fault log of a malfunctioning machine such as a locomotive. The method includes obtaining data associated with operation of the malfunctioning machine from a user at a second computing unit coupled via a communications network such as the Internet to a first computing unit such as a centrally located server operable to provide data associated with analysis of the malfunctioning machine, and providing at the second computing unit at least one of a diagnosis of and a repair for the malfunctioning machine based on the data associated with the operation of the malfunctioning machine and the data associated with analysis of the malfunctioning machine.

Abstract: A data processing system and method stores a relational database in which audit records are stored without compromising the ability to detect data tampering. The technique provides for detection of unauthorized row modification, row deletion, and row insertion. Extra measures are incorporated to protect from administrator attacks. In addition, the technique enables integrity checking and audit log archiving without having to suspend or bring down the audit subsystem. These on-line capabilities are especially important in mission critical applications which must satisfy the requirement that the application be disabled if the audit subsystem is not functioning properly.

Abstract: The present invention provides a method for keeping a file system in a consistent state and for creating read-only copies of a file system. Changes to the file system are tightly controlled. The file system progresses from one self-consistent state to another self-consistent state. The set of self-consistent blocks on disk that is rooted by the root inode is referred to as a consistency point. To implement consistency points, new data is written to unallocated blocks on disk. A new consistency point occurs when the fsinfo block is updated by writing a new root inode for the inode file into it. Thus, as long as the root inode is not updated, the state of the file system represented on disk does not change. The present invention also creates snapshots that are read-only copies of the file system. A snapshot uses no disk space when it is initially created. It is designed so that many different snapshots can be created for the same file system.

Abstract: The present invention can be applied to an operation input processing apparatus provided with an operation input executing section which issue tickets in response to users' input operations. A personal computer extracts an application program applied for the operation input processing apparatus from a software resource containing a plurality of application programs and operates the operation input executing section by executing the extracted application program. Thereby the operation input processing apparatus having various functions can operate application programs easily without damage thereto.

Abstract: A storage system is provided which preserves data integrity, even when communications line, or similar, errors arise between the local disk system and the remote disk system. When there is no communication line error between the local disk system and the remote disk system, the local disk system sends a time stamp or the write order information with the write data to the remote disk system. This enables the remote disk system to make a copy with data integrity on the disk unit in the remote disk system itself. If there is a communication line error, the remote disk system allocates an empty disk unit and makes a copy with data integrity on the allocated disk unit after the communication line error between the local disk system and the remote disk system is detected.

Abstract: A storage device for a computer, combining an audit trail storage with (1) a connector adapted for connecting the storage device to a connection point of the computer, (2) a primary storage having first data stored thereon, and adapted for sending the first data to the computer in response to a corresponding read command received at the connection point, and (3) secondary storage adapted for storing second data in response to a corresponding write command received at the connection point and further adapted for sending the second data to the computer in response to a corresponding read command received at the connection point. The audit trail storage is adapted for recording a log of communication activity occurring at the connection point.

Abstract: The present invention is directed to a method and mechanism for accessing recovery log information in a database system. The data stored in the recovery log is presented as a relational database “view,” which can be queried and accessed using relational database statements even though the underlying recovery log data may be stored in a non-relational format. According to an aspect of the invention, the recovery log data is thus encapsulated by the view presented to users of that data.

Abstract: Parametric data accumulation means are accumulated in a Terminal Server data file which uses a performance measurement tool program to accumulate operational data occurring in multiple client users which operate on a Terminal Server. Data is accumulated in regard to the log-on time for multiple and various different types of application programs. Each of these parameters are evaluated over a sequence of different operating conditions during periods where the parametric evaluations occur when there is a small number of client users and then over a sequence of expanded operations until there is a large number of concurrent active client users. Subsequently, the Terminal Server data file is formatted and categorized into a database which is used to create a graphical chart of performance plus specific lists of performance for each client-user correlated to each available Application Program.

Abstract: The system and method of this invention automatically manages a group of computers by automatically gathering data, storing the data, analyzing the stored data to identify specified conditions, and initiating automated actions to respond to the detected conditions. The invention, hereafter “SYSTEMWatch AI-L”, comprises a SYSTEMWatch AI-L client which turns a computer into a managed computer, a SYSTEMWatch AI-L console, which turns a computer into a monitoring computer, a SYSTEMWatch AI-L send facility, which allows a system administrator to send commands to various SYSTEMWatch AI-L clients through the SYSTEMWatch AI-L console, and a SYSTEMWatch AI-L report facility which allows a system administrator to query information collected and processed by the SYSTEMWatch AI-L clients and SYSTEMWatch AI-L consoles.

Abstract: A log acquisition method is provided that allows a processing log of software to readily be acquired and reduces the man-hours needed for analyzing a bug. The log acquisition method is a method for acquiring a runtime log of a program 91 including a function (FuncAA), comprising the step of changing the address of the function (FuncAA) loaded to the address of a function (92) for log acquisition and selecting the function (Func AA), wherein the function (92) for log acquisition comprises the steps of: calling the function (Func AA) (96) the log of which is to be acquired to cause a predetermined process to be executed (97), receiving the result of the execution (98), and passing said result to said program 91 (101), recording given information when calling the address of the selected function (Func AA) (95, 100), and recording given information when receiving the result of the execution of the selected function (Func AA) (99, 100).

Abstract: A data processing apparatus has a direct access non-volatile memory storage device having a plurality of extent files for storing log records therein; an allocating unit for allocating a current extent file to be used for storing log records; a writing unit for writing log records into the current extent file until the current extent file cannot store any further log records; and a key-pointing unit for performing a key-pointing operation on the written log records when the writing unit has reached the point where no further log records can be stored in the current extent file.

Abstract: A data storage system and a method of managing data in the storage system. A method of performing a write to a data storage system, including a first storage device and a second storage device, may include writing a first set of header information to a first storage device and a second storage device. The first set of header information includes a first sequence number and a second sequence number, in which the first set of header information includes a first sequence number incremented to indicate a change from the second sequence number. The method may also include returning status of completion of writing the second set of header information. Invalid data or an interruption may also be detected by examining the first and second sequence numbers. Data is written to the first storage device and the second storage device. Then, a second set of header information is written to a first storage device and a second storage device.

Abstract: A system and method for providing at least a portion of the service history of a processor-based device is provided. The present invention is directed to a system and method for providing at least a portion of the service history of a processor-based device. In one embodiment, the present invention comprises an application for providing at least a portion of the service history of a processor-based device on which the application resides. The application comprises code for receiving information relating to at least a portion of the service history of the processor-based device, code for entering the received information into a data structure, and code for providing at least one web-based page, the at least one web-based page comprising at least a portion of the information entered in the data structure.

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: Systems and methods consistent with the present invention provide for remote tracking of the reboot status for a plurality of user terminals. Each user terminal runs a start-up routine capable of creating a record of information about the terminal, including reboot status. The record of information is stored in log file on a file server, along with the records of information from other user terminals. A collection routine executed by a central server collects the log files from the file servers and stores the records in a database. Based on the records stored in the database, various status reports may be generated that reflect, among other things, a reboot status associated with the user terminals over a predetermined period of time.

Abstract: A system which provides a completely redundant configuration including dual Fibre Channel fabric links interconnecting each of the components of two data storage sites, wherein each site comprises a host computer and associated data storage array, with redundant array controllers and adapters. The array controllers perform a command and data logging function which stores all host write commands and data ‘missed’ by the backup storage array during a situation wherein the links between the sites are down, the remote site is down, or where a site failover to the remote site has occurred. Log units are used to store, in order, all commands and data for every transaction which was ‘missed’ by the backup storage array when one of the above system error conditions has occurred.

Abstract: A method and system allows multiple compute elements to independently read and clear error register logs, discard invalid data and ensure that a user receives information stored in error log registers. Error log registers are not cleared until its information is successfully retrieved by a compute element. A counter maintains a count of errors for which detailed error information has been lost.

Abstract: A method, system, and apparatus for recovering form an instruction fetch error is provided. In one embodiment, a data processing system maintains a primary copy and an alternate copy of a set of instructions for a software component. The instructions for performing the processes of the software component are fetched from the primary copy for execution by a processor. A pair of pointers is maintained in each copy identifying the beginning of each copy. Responsive to a determination that an instruction fetch error has been received, a corresponding current instruction in the alternate copy is determined and the software component is restarted by fetching and executing instructions from the alternate copy starting with the corresponding current instruction. The corresponding current instruction is determined by subtracting the beginning address of the copy with the error from the address of the current instruction, then adding the beginning address of the alternate copy.

Abstract: A system, method, program, and data structure for performing a backup operation of a target file. At least one operation is initiated to perform at least one delta backup of the target file to at least one delta backup set. A delta backup set includes changes made to a version of a full backup set of the target file generated at a first time, such as an incremental or differential backup operation. The at least one delta backup set is assigned a name component indicating the version of the full backup set generated at the first time subject to the delta backup and an operation is initiated to perform a full backup of the target file to a version of the full backup set at a second time. The second time follows the first time. A determination is made of all delta backup sets having the name component indicating the version of the full backup set generated at the first time during the full backup operation at the second time.

Abstract: Utilizing only a single input/output (I/O) session to commit a single message transaction to a non-volatile storage within a message transaction system is disclosed. In one embodiment, a method first determines an error detection value, such as a checksum, for a single transaction. The single transaction and the value are written to the non-volatile storage in only a single I/O session. The single transaction is committed upon the successful writing of the transaction and the error detection value to the storage. Upon recovery from a system failure, the error detection value for the transaction is redetermined; if it does not match the value as has been stored to the storage, then the transaction is aborted. Otherwise, the transaction has been committed.

Abstract: A data processing arrangement (100) and method for fuzzy backup and restore of MQSeries shared queues held in coupling facility list structure (106). Periodically backups are taken of the data held in the CF list structure by backing up messages in the sequence uncommitted puts (220), committed puts (230), uncommitted gets (240) and expired messages (250), whereby all messages may be backed up in the backup means except for exceptions which are recorded in the record log. In the event of media failure of the coupling facility, data can be restored by restoring messages in the sequence restoring messages from the backup means (320), replaying messages from the record log means (340) and determining final disposition of messages from replay of the record log means (350). This provides the advantage of allowing the number of log records written to be reduced.

Abstract: A method, system and apparatus for cascading backup mirrors are provided. A mirroring map is created. The mirroring map includes at least three mirrors. A first mirror of the three mirrors is set to synchronize to a second mirror and a third mirror is set to synchronize to the first mirror. The first and the third mirror are backup mirrors and the second mirror is a working mirror. One of the backup mirrors is located remotely and the other locally.

Abstract: The present invention is directed toward creating backup copies of previously saved data before it is modified by a crashed computer program executing in a preemptive multitasking operating system environment. The invention is advantageous in that it protects against data loss and corruption caused by operating system calls issued by malfunctioning, crashed computer programs. A method in accordance with the invention comprises the steps of: (a) monitoring operating system calls made by a crashed program; (b) intercepting a selected group of operating system calls made by a crashed program before they are executed by an operating system; (c) logging a subset of the selected group of intercepted operating system calls in a memory; (d) creating backup copies of data potentially modified by a further subset of the selected group of intercepted operating system calls; and (e) passing intercepted operating system calls to an operating system.

Abstract: A system for generating a virtual point-in-time copy of a selected subset (e.g., a selected volume or logical unit) of a storage system. The present system operates by using a bitmap in storage system controller cache memory to indicate blocks of memory in the selected volume that have been overwritten since the snapshot was initiated. When a write to the selected volume is requested, the cache bitmap is checked to determine whether the original data (in the area to be overwritten) has already been copied from the selected volume to a temporary volume. If the original data was previously copied, then the write proceeds to the selected volume. If, however, the original data would be overwritten by the presently requested write operation, then an area containing the original data is copied from the selected volume to a temporary volume. Reads from the temporary volume first check the bitmap to determine if the requested data has already been copied from the selected volume to the temporary volume.

Abstract: The present invention is directed to a method and mechanism for accessing recovery log information in a database system. The data stored in the recovery log is presented as a relational database “view,” which can be queried and accessed using relational database statements even though the underlying recovery log data may be stored in a non-relational format. According to an aspect of the invention, the recovery log data is thus encapsulated by the view presented to users of that data.

Abstract: Disk drives are mirrored through duplication controlled by disk controllers. Each disk controller controls writing to a set of disk drives. A disk write request to one disk controller causes that disk controller to write to one of its disks and to transmit the write request to another controller that in turn writes to its disk. The second controller then acknowledges the write to the first controller, which in turn acknowledges the write to the computer issuing the request. The first controller further logs the writes in a log file. This allows efficient resynchronization after mirroring is broken and reestablished, as well as removing cable length restrictions between controllers.

Abstract: A method for diagnosing faults in a computer-based system. A log of errors of different kinds that have been recorded in the system is read, and errors of those kinds that are relevant to one or more predetermined types of faults that can occur in the system are selected from the log. The selected errors are filtered so as to compose one or more events, each event comprising one or more occurrences of one or more of the relevant kinds of the errors. The composed events are analyzed to reach an assessment that at least one of the predetermined types of faults has occurred.

Abstract: The invention provides a method for error detection of multi-threaded software. The method comprises executing an application which uses a logger that collects log statements, collecting at least one log statement from at least one application thread and storing the at least one log statement in memory, and allowing the collected log statement to be persisted in case of an error in a production environment.

Abstract: A recovery logging method wherein when a node in a computer network becomes unavailable, file systems which require verification and are locked are logged in a recovery log and checking of other file systems continues. In this manner, the host node effectively utilizes time which would otherwise be spent waiting for a file system to become available. Upon completing available file system verifications, those file systems which were logged are checked for availability via background processing. When a logged file system becomes available, it is then verified. During the time spent waiting for a logged file system to become available, the affected node is available for other processing.

Abstract: Techniques are provided for executing an operation in which a client invokes a replicated object. According to one technique, a primary replica of a replicated object receives a first request from a client, wherein the first request includes a request identifier. Rather than immediately attempting to process the request, the primary replica determines whether a record exists that corresponds to the request identifier. If a record exists that corresponds to the request identifier, then the primary replica responds to the first request with a reply associated with the record. If no record exists that corresponds to the request identifier, then the primary replica performs the steps of: starting a transaction; as part of the transaction, processing the request; as part of the transaction, storing a record associated with the request identifier and a reply to the request; committing the transaction; and delivering the reply to the client. The client may itself be a replicated object.