Abstract: The present invention provides a storage system whereby it is also possible to back up the generational management information of a copy source disk array device. The disk array device of the primary site manages back-up data of a main volume, in a plurality of generations, by means of differential snapshots. The differential data of the main volume and the main pool is transferred from the primary site to the secondary site, at a prescribed timing. The secondary site holds the secondary volume, which is a copy of the main volume, and a secondary pool which is a copy of the main pool. The primary site also transfers the generational management information to the secondary site. The generational management information may also comprise a differential bitmap table and a withdrawal destination address management table. The secondary site holds a copy of the generational management information.

Abstract: A prologue and an epilogue of a function are hooked. Completion of the prologue is stalled in a first state of a stack frame, and a copy of the first state of the stack frame is saved. Completion of the prologue is initiated, permitting execution of the function. Completion of the epilogue is stalled in a second state of the stack frame. The saved copy of the first state of the stack frame is located and compared with the second state of the stack frame. A determination is made whether the stack frame is corrupted based on the comparison. Upon a determination that the stack frame is corrupted, the second state of the stack frame is replaced with the copy of the first state of the stack frame, and completion of the epilogue is initiated, allowing the function to complete.

Abstract: The invention relates to a data transmission method and a radio system that comprises a first (260) transceiver and a second transceiver (264) that are in radio contact with each other. The first transceiver (260) comprises means (500, 504) for forming data blocks for transmission in such a manner that the data blocks are given identifiers for identification. The second transceiver (264) comprises means (512) for receiving data blocks transmitted and retransmitted by the first transceiver, and means (524) for detecting a failure in receiving a data block. The second transceiver (264) comprises means (530) for maintaining information on the position of a window belonging to a finite identifier space, and means (524) for comparing the identifiers of the re-received data block and the earlier received data block with each other and for defining the data blocks as the same, and means (524) for combining the data blocks defined as the same.

Abstract: A method and apparatus to recover a set of data from a full backup and an incremental or differential backup are described. This includes a source directory that was modified between the full backup and the incremental or differential backup. The full backup is restored, including the source directory, and a new directory is created to replace the restored directory when the incremental or differential backup is applied to the restored full backup. Content for an entry from the modified source directory in the incremental or differential backup is created in the new directory if the corresponding content is present in the incremental or differential backup. If the content for the entry is not present in the incremental or differential backup, then the entry in the new directory is linked to corresponding content in the restored directory from the full backup.

Abstract: Methods and systems for efficient and accurate re-starting of data transfers using volatile data transfer mechanisms, such as pipes, following an error. According to one embodiment, portions of the transferred data can be saved in a fallback file. In addition, checkpoint commands can be periodically provided, upon which much of the data in the fallback file can be overwritten. During the original transmission, the data that has passed through the mechanism can be counted, and a signature for the data that has passed can be accumulated. After certain error conditions, the data in the fallback file can be recovered and passed to the receiving process and the transmission can then be resumed at the point where it had left off. After other errors requiring a complete re-start, a second signature of the re-transmitted data can be accumulated and original and second signatures compared to determine if the data is valid.

Abstract: A method of utilizing timestamps for the global ordering of event information, particularly hardware error reporting, is disclosed. Locally generated time stamps are associated with hardware errors or other events. The timestamps form the basis for the global ordering of event information. The timestamps are normalized, either through a pre-synchronization process with a common time, or through the use of offsets maintained either locally near system chips or by the system processor. Once normalized, the timestamps can be compared to determine a first occurring event among multiple reported events.

Abstract: A computer monitoring system in which a management console and a plurality of computers are connected to each other via a communication path, the plurality of computers constitute one or more computer groups and the one or more computer groups are logically associated by a tree structure having the management console as the root, wherein each of the plurality of computers has a monitoring element for performing mutual monitoring by mutual communication with other computers in the own computer group on the basis of computer addresses registered in an address list, and a trouble detecting element for detecting any trouble, the result of trouble detection being notified to all the computers belonging to a computer group which constitutes the parent node.

Abstract: A system for minimizing downtime in an appliance-based business continuance architecture is provided. The system includes at least one primary data storage and least one primary host machine. The system includes an intercept agent to intercept primary host machine data requests, and to collect information associated with the intercepted data requests. Moreover, at least one business continuance appliance in communication with the primary host machine and in communication with a remote backup site is provided. The appliance receives information associated with the intercepted data requests from the intercept agent. In addition, a local cache is included within the business continuance appliance. The local cache maintains copies of primary data storage according to the information received. Furthermore, the remote site is provided with the intercepted data requests via the business continuance appliance, wherein the remote site maintains a backup of the primary data storage.

Abstract: In one aspect of the invention, a method of dynamically switching among a plurality of fault tolerance schemes is provided. The fault tolerance schemes are associated with a fault tolerance mechanism that executes in a distributed system. The method comprises obtaining a wait time of at least one user interface event occurring in the distributed system. The wait time includes at least one of a communications time, a service time and a fault tolerance time. The method further comprises determining whether a mean of the wait time is greater than a predetermined mean wait time threshold. The method also comprises determining whether the communications time, the service time and the fault tolerance time are mutually independent when the mean of the wait time is greater than the predetermined mean wait time threshold.

Abstract: The present invention provides a backup method for a storage control device that instructs a storage device to split a primary volume and a copy volume in the storage device, and to execute a backup operation from the copy volume to a backup volume. The storage device includes the backup volume for the copy volume. The backup method includes: the storage control device allocating a specified number of generations of the backup volume in the storage device for the copy volume; instructing the storage device to split the pair; executing a virus check on the copy volume; copying contents of the copy volume to the backup volume as a most recent generation backup if no virus is detected; updating generations in the backup volume for generations prior to the most recent generation; and instructing the storage device to re-link the split pair.

Abstract: A method for recovering data from a redundant storage object comprises a command, executable upon a redundant storage object, which provides a mechanism for discovering the existence of copies of the data image and the number of copies of the data image available. The present invention further provides the capability of retrieving a copy of the data image(s) from underlying virtualization layers. By querying specific layers of the IO path to determine if a specific layer has copies of the data image, the number of copies may be determined and specified copies of the data image retrieved. This allows higher layers within a system to perform recovery if incorrect data is detected.

Abstract: A method for enabling recovery of data stored in a computer network, the computer network comprises a plurality of computer nodes, the method comprising the steps of generating a set of redundancy data based on a predetermined relationship between a first set of data and a second set of data, injecting the first set of data, the second set of data and the set of redundancy data into separate looping paths of the computer network, wherein a looping path is a path along a plurality of computer nodes in which data is transported, and the looping paths are defined in separate communication channels between the computer nodes and pass through at least one common node of the computer network, such that the redundancy data and the second set of data can be used to reconstruct the first set of data based on the predetermined relationship between the first and second set of data when the first set of data is lost, thereby enabling the recovery of data stored in the computer network.

Abstract: File system restoration is made more flexible through the use of indicators of individual file restoration status throughout the restoration process. Such indicators are particularly useful in the restoration of large file systems where, for example, the number of files may range upwards of several hundred million. Since file system restoration for large systems takes such a relatively long time, the present invention provides various degrees of individual file access even as the restoration process is being carried out. During file system restoration times, file access may be full or limited to a file's attributes. Most advantageously, the present invention is capable of providing full, dynamically driven (on-demand) file access even during file system restoration operations.

Abstract: An operating system is logically separated into a partition for a kernel and a partition for an audio subsystem having logically separate subpartitions. An audio application generates a first audio datastream by executing the audio subsystem. The context of a process for processing the first audio datastream is preserved in a first subpartition. The processing of the first audio datastream with the process takes place in a second subpartition. When the process commits an access violation, the process is recovered by restoring in the audio subsystem the preserved context from the first subpartition.

Abstract: A system includes a controller to store point-in-time representations (or snapshots) of data taken at different time points from storage unit of a storage subsystem. Data can be restored from one of the point-in-time representations, with point-in-time representations taken later than the one point-in-time representation maintained enabled to allow a subsequent restoring of data from the later point-in-time representations.

Abstract: A system and method for logging and restoring the state of execution of resource transactions in a shared system resource by logging and restoration of state machine information. Each state machine logging mechanism includes a state machine log generator for extracting state machine information and generating and storing a state machine log. The resource may include dual, concurrently operating control/processing subsystems and may include corresponding functionally integral but physically separate state machine log mirroring mechanisms for receiving and restoring mirror copies of the state machine information.

Abstract: A method and system of providing a write-accessible storage checkpoint is disclosed. According to one embodiment of the present invention, a first writable storage checkpoint is associated with a first storage checkpoint of a storage checkpoint chain where the storage checkpoint chain is independent of the first writable storage checkpoint and a write operation is then performed utilizing the first writable storage checkpoint.

Abstract: A method and apparatus for providing an undoable programming language. More specifically the present invention relates to providing a fully undoable programming language, where the language includes a fully undoable core language portion and a conventional language portion. In an embodiment of the present invention, a method of encoding a general-purpose undoable programming language to enable fully undoable instructions includes encoding a fully undoable core imperative language portion having a plurality of undoable core instructions, each of the plurality of undoable core instructions to perform at least one undoable operation upon execution, and the at least one undoable operation being fully undoable until final termination of a program written using any of the plurality of undoable core instructions.

Abstract: A synchronous data mirroring technique includes a log forwarding process and a consistency point (CP) process. During log forwarding, a source storage server receives write requests from clients, creates a log entry for each request in nonvolatile memory, and transmits each log entry to a destination storage server at a mirror site. The destination storage server writes each log entry to a file. If a primary volume becomes inaccessible due to a failure, the file is used to produce an updated mirror volume. The CP process includes updating a primary volume based on the write requests, and updating the mirror volume to reflect the updated primary volume. The mirror volume is updated by transmitting CP data from the source storage server to the destination storage server, and using the CP data to update the mirror volume through a network administration layer and a storage layer in the destination storage server.

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: A technique for recovering a dropped table is provided. One or more table spaces are specified prior to one or more tables being dropped from the specified one or more table spaces. When a table is to be dropped from the one or more specified table spaces, a table identifier, a time stamp, and table definition attributes are stored for the dropped table in a data structure and the table is dropped. Upon receiving a request to restore a table space from the one or more specified table spaces, each of the one or more tables in the table space being restored is recovered using the data structure.

Abstract: A storage system is composed of storage apparatuses each separately installed at three sites for the purpose of disaster recovery, wherein data stored in one of the storage apparatuses designated as a replication source is also managed in one of the other two storage apparatuses designated as a replication destination, such that in the event of a failover execution request from an information processing apparatus, data stored in the storage apparatus designated as the replication source is managed also in the storage apparatus of the other two storage apparatuses designated as a spare.

Abstract: Restoration of data is facilitated in the storage system by combining data snapshots made by the storage system itself with data recovered by application programs or operating system programs. This results in snapshots which can incorporate crash recovery features incorporated in application or operating system software in addition to the usual data image provided by the storage subsystem.

Abstract: An example of a method for error tracking includes sending a data object to a first location. This example also includes determining if the data object was successfully stored at the first location, and if so, storing meta data corresponding with the data object, wherein the meta data includes first path information. This example of the method also includes sending the data object to a second location. This example further includes determining if the data object was successfully stored at the second location, and if so, adding second path information to the meta data corresponding with the data object, to update the meta data. Some examples of the invention may be called a data centric error tracking and problem analysis method (and system), because the error tracking is generally based on the path traveled by the data.

Abstract: The usage amount of a pool area is avoided from becoming equal to 100%, thereby preventing all snapshot images from being crashed. There is provided a disk-array apparatus including a control processor. Here, the control processor controls a data reading/writing from/into a first logical volume created using a memory area of plural disk drives, and controls past data such that the past data is written into a second logical volume as differential data on each generation basis, the past data being stored into the first logical volume, and manages the differential data. If the amount of the differential data stored into the second logical volume has exceeded a first predetermined value, the control processor determines a generation of the differential data to be deleted from among the differential data written into the second logical volume. The control processor deletes the differential data of the generation determined.

Abstract: A system and method for fault-tolerant synchronization of replica updates for fixed persistent consistency point image consumption. PCPIs are consumed at a fixed level and each coalesced PCPI presents a valid version of the source file system from some point in time. The qtrees concurrently move through a coalescing cycle wherein some qtrees are updated, some may update partially and some may not update at all. Partially updated qtrees are rolled-back to the previous state, after which all qtrees are transitioned to a stable state.

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 data processing system includes at least a first storage system, a second storage system and a third storage system. The third storage system maintains a replication of data stored in the first storage system. When updating data in the first storage system, the first storage system updates the replication of data stored in the third storage system and creates a journal. The journal is formed from a copy of data used for update and update information such as a write command for update, etc. The second storage system also maintains a replication of data stored in the first storage system. The second storage system obtains the journal, and updates data stored therein corresponding to data stored in the first storage system in the order of data update performed in the first storage system. When updating data stored in the third storage system corresponding to data stored in the first storage system, the third storage system creates a journal using data update numbers created in the first storage system.

Abstract: A service processor for a server system includes an event log that, once full, stores recent events by overwriting events of intermediate age so that the information required to diagnose both cascade errors and hangs are preserved. This contrasts with bottom-up buffers that discard recent events when full and with circular buffers that discard the oldest events when full. The event log can be reset by moving an exception region, that is, a region that is not overwritten by recent events. Alternatively, a partial reset can initialize an exception region (e.g., a bottom-up sublog), while a circular region or sublog continues to operate without being reset.

Abstract: In a storage apparatus system, after having obtained the coherency between a file system of a main storage apparatus system and the stored data, a host computer issues a freezing instruction to a main DKC which transfers in turn the disk image at a time point of the issue of freezing instruction to a sub-DKC and then transmits a signal, showing that all the data has been transmitted, to the sub-DKC. In the sub-DKC, the disk image at a time point of reception of the freezing instruction is held until a signal showing that all the data has been transmitted is issued next time, and when the main storage apparatus system becomes unusable at an arbitrary time point, the data of the disk image, at a time point of issue of the freezing instruction, which is held by the sub-storage apparatus system can be utilized.

Abstract: In one embodiment, a first storage device and a second storage device form a mirror. When the first storage device loses synchronization with the second storage device, data present in the second storage device but not in the first storage device are identified. The identified data are then copied to the first storage device. In one embodiment, a method of rebuilding data in a storage device includes the act of replacing a failed storage device with a replacement storage device. Up-to-date data for the failed storage device, which may be stored in a corresponding mirror, may then be copied to the replacement storage device. Thereafter, the replacement storage device and any other storage devices that have lost synchronization with their mirror are resynchronized.

Abstract: A transactional file system developed to function with flash memory is described. The file system provides for efficient storage of file system meta-information, performs robust transaction logging, and performs other related features. In one described implementation, metadata is stored in-line with data. In another embodiment, a transaction log is maintained by storing transaction information associated with requests to perform file transactions. The transaction information is stored at arbitrary physical sector addresses on the flash medium. In still another embodiment, a transaction log is stored in a physical sector of a flash medium. The transaction log contains transaction information associated with performing a file request. Metadata is written into a spare area of the physical sector indicating that the physical sector contains transaction information.

Abstract: Provided is a method, system and program for synchronizing sequential subtasks of a task, so that the subtasks can be dispatched to generate operations in a particular sequence. In one embodiment, a subtask which has been prepared for dispatching is queued in a queue until the queued subtask is the next subtask in sequence for dispatching. In one embodiment, the subtasks may be sorted in the queue by task and by subtask sequence.

Abstract: Methods and systems for managing disk capacity allocated to a data log in a source data storage system during a merge process are disclosed. Data in the data log may be merged into corresponding data on a destination storage system connected to the source data storage system by at least one communication link. In one embodiment a method comprises maintaining a ratio of merge writes out of the data log to writes from a host computer into the data log within a desired range until the write process reaches a predetermined distance from the end of the data log, and quiescing writes from a host computer into the data log until the data log is fully written to the destination storage system.

Abstract: An redundant array of independent disks (RAID) storage device is provided. The RAID comprises M number of storage devices, and the storage blocks of the same J-column in each storage device comprises complete stripe blocks and at least a plurality of partially complete stripe blocks. Inside the same stripe block, the total number of the storage blocks (L) is smaller than the number of the storage device (M), and the quantity of the storage blocks (M) is not multiple of storage blocks (L).

Abstract: Diagnosis of corruption in interrelated data entities uses a graph of nodes and edges. Datum nodes represent the data entities, relationship nodes represent the relationships among the data entities. The datum nodes are connected through their relationship nodes by the edges. When corruption is detected, the relationships are analyzed and each edge connecting a datum node to a relationship node is removed from the graph when the corresponding relationship is invalid. The datum nodes that remain connected to their relationship nodes form a subgraph and the corresponding data entities are considered correct. In one aspect, if more than one subgraph is formed, the datum nodes in the largest are used. In another aspect, the data entities and relationships are analyzed to create the graph when the data entities are assumed correct. The data entities may be data and metadata of various types that can be associated with the data.

Abstract: A data processing system includes at least a first storage system, a second storage system and a third storage system. The third storage system maintains a replication of data stored in the first storage system. When updating data in the first storage system, the first storage system updates the replication of data stored in the third storage system and creates a journal. The journal is formed from a copy of data used for update and update information such as a write command for update, etc. The second storage system also maintains a replication of data stored in the first storage system. The second storage system obtains the journal, and updates data stored therein corresponding to data stored in the first storage system in the order of data update performed in the first storage system. When updating data stored in the third storage system corresponding to data stored in the first storage system, the third storage system creates a journal using data update numbers created in the first storage system.

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 a processor including at least one critical memory structure to detect an error and a processor error processing logic hardware coupled to the at least one critical memory structure.

Abstract: The present invention relates to a storage system, including a first storage unit having a first storage volume for storing data, and a second storage unit having a second storage volume communicably connected with the first storage unit, wherein the first storage unit further comprises a replication data transmission unit for transmitting the replication of data to a second storage unit when the data is written to the first storage volume, the second storage unit further comprises a replication data reception unit for writing the replication of the data transmitted by the replication data transmission unit to the second storage volume, the first storage unit further comprises a disk heart beat write unit for repeatedly writing a first heart beat message to the first storage volume at intervals within a predetermined time, and the second storage unit further comprise a disk heart beat detection unit for detecting the replication of the first heart beat message to be written to the second storage volume by the

Abstract: A system and method for disaster recovery for a plurality of computers on a computer network including creating a first image of base system data for restoring the base system of a plurality of workstations of a computer network, storing the first image on computer media, creating one or more second images application data for restoring one or more applications of the plurality of workstations on the computer network, storing the second image on computer media, creating a third image of personalized data relative to a respective workstation on the computer network and storing the third image on computer media.

Abstract: A computer executable digital video rendering restoration method is disclosed. Through setting a saving interval, data of states during the rendering process of digital videos are recorded periodically. When the rendering process is abnormally interrupted, the state data in the record file can be immediately used to restore the digital video before the last recording so that the user can continue the digital video rendering.

Abstract: A method and data processing system for providing a preload imaging process that is self-healing. The state information of a single or multi-threaded preload environment is autonomically recognized and stored in a log file along with the corresponding file images that are being preloaded. The log tracks the image files and related state information for a plurality of simultaneously executing (preloading) threads. When a crash occurs during the preload process, the log information is dynamically analyzed to determine a safe point within the respective threads to resume the preload operation. The preload process is then autonomically resumed from the safe location without necessarily having to restart the entire process.

Abstract: In general, the invention facilitates diagnosing fault conditions, such as flapping, by permitting users to request information for specific components in a network device such as a router. The invention also facilitates the diagnosis of other fault conditions, including, but not limited to, excessive numbers of dropped packets, hard drive crashes, high temperature readings, and inactive interface cards. A user may obtain a targeted log containing information relating to selected fault conditions or other network device events, rather than a system log containing information relating to all network device events, some of which may not be of interest to the user. The targeted log may be parsed and analyzed with greater ease than the system log.

Abstract: To provide a storage management device capable of performing restore at a high speed. In the storage management device that manages backup and restore of data stored in a storage device, a temporary restored image is created by applying each required delta image to the full backup image, a reverse delta image before the application of the applied delta image is created, and a number of delta application blocks concerning the applied delta image is recorded as cost information of applying delta. The delta backup restore unit determines a restore method by comparing a number of blocks, which is changed when restore is performed by applying each piece of the reverse delta image, with a number of blocks, which is changed when the restore is performed by applying each delta image, with reference to the cost information of applying delta.

Abstract: A method and mechanism for generating a snapshot in a computing system. On initiating a snapshot of a first storage, the content of a portion of the first storage that includes at least one block is copying to snapshot storage and a copied indication for each copied block is recording in a copy map. Responsive to any write request to a block for which no copied indication has been recorded in the copy map, the content of the block is copied to the snapshot storage, prior to writing to that block. The content of other blocks for which no copied indication has been recorded in the copy map is successively copied to the snapshot storage. A copied indication for each copied block is recorded in the copy map. The successive copying can be performed as a background task.

Abstract: In many systems, computer software is a common source of failure or instability. The proliferation of multiple interacting applications from several different software vendors leads to “emergent” problems that are difficult or impossible to predict or prevent. The problems are compounded by the use of networks, which introduce the added complexity of applications on multiple machines interacting in complex scenarios. As a result, many business and home users are hindered from using software-based systems to their fullest potential. More effective use of these systems can be aided by an application which can provide services for monitoring, diagnosing, and solving problems that occur in the operation of the machines at a customer facility. In the system described herein, a database contains entries with executable code that can make use of these services in order to monitor, diagnose, and solve specific problems. Each entry in the database addresses a specific problem.

Abstract: An apparatus and method of supporting the backup and recovery of a computing device. The computing device typically includes both a user computing environment and a supporting environment which enhances the stability and functionality of the user computing environment.

Abstract: A data backup and recovery system for use with at least one server interconnected with at least one storage device, including at least one data recovery device, at least one associated data recovery storage device, controlled by the data recovery device, and at least one data communication monitor. A method for data backup and recovery is also disclosed.

Abstract: In a data center, when a server is disconnected from the Internet because of illegal manipulation of a file, valid files (not manipulated) are copied to a standby server and the processing is resumed after a short period of disconnection. According to the invention, a control program P10 performs manipulation checks for all files listed in a manipulation checklist. If any of them is manipulated, it issues a request to disconnect from the external network and a request to assign a standby server to a control program P20 of a management server. Upon receipt of a disconnection completion signal and the address of a standby server b0, the control program P10 copies valid files (not manipulated) to the standby server b0, and for invalid files, requests the copies of their backup files. After finishing copying, the management server connects the standby server b0 to the external network to resume processing.

Abstract: One or more computer systems, a carrier medium, and a method are provided for backing up virtual machines. The backup may occur, e.g., to a backup medium or to a disaster recovery site, in various embodiments. In one embodiment, an apparatus includes a computer system configured to execute at least a first virtual machine, wherein the computer system is configured to: (i) capture a state of the first virtual machine, the state corresponding to a point in time in the execution of the first virtual machine; and (ii) copy at least a portion of the state to a destination separate from a storage device to which the first virtual machine is suspendable. A carrier medium may include instructions which, when executed, cause the above operation on the computer system. The method may comprise the above highlighted operations.