Abstract: A system and program storage device for extracting data of a buffer after a failure of an operating system. An application is registered prior to the failure. The registering includes identifying a buffer in which the data to be extracted is stored prior to the failure. The buffer is reserved to maintain the data residing in the buffer as unchanged from initiation to completion of a fast reboot of the operating system. The fast reboot is responsive to the failure. An in-memory file is generated during the fast reboot, points to the data residing in the buffer, and is stored in volatile memory and not in persistent storage. The data is extracted via an instruction which is executed by the application after completion of the fast reboot, and which operates on the in-memory file.

Abstract: The present invention provides a method for optimizing the processing of backend transactions. The method operates by identifying a transaction group comprising related transactions for processing from a program executing on a computer and determining a degree of necessity for each of the related transactions, where the degree of necessity represents a predetermined time period given for each of the plurality of related transactions to successfully complete execution. The method includes determining which of the plurality of related transactions depend upon the successful completion of a transaction, assigning a priority for each of the related transactions, and scheduling the execution of the related transactions based upon priority. The method further includes canceling the execution of any of the related transactions that depend upon a transaction that does not successful complete execution, and returning to the program any data resulting from the execution of the related transactions.

Abstract: Data associated with the state of a parity update operation in a disk array system such as a RAID-6 system is stored during performance of the operation so that, in the event the operation is interrupted, recovery may be initiated using the stored data. The stored data may include a state indicator that is indicative of the status of the parity update operation, and snapshot data (e.g., a delta value indicative of a difference between new and old data) captured during the parity update operation.

Abstract: A common logging system (a “virtual logging system”) that presents to one or more log clients the appearance that each log client is interacting with a dedicated logging system. In reality, the virtual logging system is multiplexing virtual log streams, including log records, for each log client into a single transactional log. In particular, the invention is directed at a system and method for decoupling space reservation between a plurality of distributed components and a core component in the virtual logging system.

Abstract: A method for memory management in smart card controllers by writing of data into a data space in a persistent memory is described. In order to save memory space the persistent memory is split into blocks with fixed data length having logical block numbers; whereby the size of blocks is selected such that it corresponds to the physical size of the pages of the EEPROM memory existing on the card. Fragmented blocks are used by comprising segments being independent from each other, whereby these segments are part of different data fields. A Block Allocation Table (BAT) is used in order to distinguish the physical place of the block in memory from the logical block number and to address different segments in the block.

Abstract: A storage system maintains a journal and a snapshot of one or more data volumes. Two journal entry types are maintained, an AFTER journal entry and a BEFORE journal entry. Two modes of data recovery are provided: “fast” recovery and “undo-able” recovery. A combination of both recovery modes allows the user to quickly recover a targeted data state.

Abstract: A system and method in a data processing system for recovering data in a file system. A request to modify a data block in the file system is detected. In response to detecting the request to modify the data block, metadata describing the data block in the file system is written in a log. In response to detecting an error during the writing of the metadata, an error counter is incremented. Finally, in response to a request to recover the data in the file system, the metadata is read only if the error counter is less than or equal to a predetermined value.

Abstract: A system and method are disclosed for providing journal recovery in a multi-node environment which comprises determining whether a block was updated by a first node; determining whether the block is associated with a lock held by a second node; and writing the block to a final location if the block is not associated with a lock held by the second node.

Abstract: A computing system processes memory transactions for parallel processing of multiple threads of execution with millicode assists. The computing system transactional memory support provides a Transaction Table in memory and a method of fast detection of potential conflicts between multiple transactions. Special instructions may mark the boundaries of a transaction and identify memory locations applicable to a transaction. A ‘private to transaction’ (PTRAN) tag, directly addressable as part of the main data storage memory location, enables a quick detection of potential conflicts with other transactions that are concurrently executing on another thread of said computing system. The tag indicates whether (or not) a data entry in memory is part of a speculative memory state of an uncommitted transaction that is currently active in the system.

Abstract: Techniques are provided for guaranteed undo retention. The techniques include a database server attempting to store undo information in undo storage. In order to store the undo information, the database server may overwrite expired undo records; write to empty undo extents; allocate new undo extents and write to the newly-allocated extents; or overwrite unexpired undo records that do not have guaranteed undo retention. If an undo record does not have guaranteed undo retention, then the undo record may be overwritten before the expiration time has elapsed. If no undo extent is empty or unallocated, and if all of the undo records are unexpired and have guaranteed undo retention, then the database system has, at least temporarily, run out of usable and reusable space and an error may be reported to an appropriate party.

Abstract: A process group resource manager for managing protected resources during transaction processing is disclosed. The process group resource manager comprises a first process configured to provide access to a protected resource during one or more transactions, the first process being further configured to construct a transaction record for each respective transaction, wherein each transaction record includes each request message received by the first process and each response message sent by the first process during a particular transaction. The process group resource manager further comprises a second process configured to serially replay the transactions in which the first process participates, the second process being configured to cause a particular transaction to rollback if the replay of that transaction does not match the transaction record constructed by the first process for that transaction.

Abstract: A method and system provides reversibility of an operation performed by a user of an application program and associated with a modification to an object model of the application program, such as a spreadsheet program or other office productivity application program. The top item of a first undo stack associated with the application program is determined, saved, and copied to a second stack functioning as a replicated undo stack. According to one aspect of the invention, such steps are performed prior to calling an object model method that clears the first undo stack. The top item of the second replicated undo stack is placed back onto the first undo stack.

Abstract: A method for transactional writing of data into a persistent memory comprising memory cells includes a transactional writing step and a transaction recovery step. The transactional writing step comprises one or more memory cell writing steps comprising the sub-steps of writing in a transaction buffer as transaction buffer entry the current data value and the corresponding address of the respective memory cell, writing a first valid marker for the memory cell in the transaction buffer, and writing a new data value to the memory cell. The transaction recovery step is performed in case of an abortion of the transactional writing step for restoring the current data values of the aborted transaction in the persistent memory, the transaction recovery step comprising the sub-step of writing a transaction recovery marker to the transaction buffer indicating the start of the transaction recovery.

Abstract: A storage system maintains a journal and a snapshot of one or more data volumes. Two journal entry types are maintained, an AFTER journal entry and a BEFORE journal entry. Two modes of data recovery are provided: “fast” recovery and “undo-able” recovery. A combination of both recovery modes allows the user to quickly recover a targeted data state.

Abstract: A method and apparatus for efficient register checkpointing is herein described. A transaction is detected in program code. A recovery block is inserted in the program code to perform recovery operations in response to an abort of the first transaction. A roll-back edge is potentially inserted from an abort point to the recovery block. A control flow edge is inserted from the recovery block to a entry point of the transaction. Checkpoint code is inserted before the entry point to backup live-in registers in backup storage elements and recovery code is inserted in the recovery block to restor the live-in registers from the backup storage elements in response to an abort of the transaction.

Abstract: Data associated with the state of a parity update operation in a disk array system such as a RAID-6 system is stored during performance of the operation so that, in the event the operation is interrupted, recovery may be initiated using the stored data. The stored data may include a state indicator that is indicative of the status of the parity update operation, and snapshot data (e.g., a delta value indicative of a difference between new and old data) captured during the parity update operation.

Abstract: Described is a revert preview mechanism, which gives the user a chance to temporarily remount a storage volume with the contents of a shadow copy, and then evaluate the computer system as if reverted, including allowing full I/O read and write operations to the storage volume. A temporary storage location is provided to cache data writes. Read requests are read back from the temporary storage location if the corresponding volume location has been written, or are read back from the shadow copy of the volume if not written since the revert preview operation began. In the case of a revert preview of the boot volume, an API is used to specify a correct shadow copy instance of the system registry hive, which needs to be loaded following reboot, but before the shadow copy driver is loaded. Use of the API loads the correct instance on the next reboot.

Abstract: A system and method for tracking and restoring computer configuration are disclosed. In one aspect, the system and method monitors for a series of changes in watched one or more computer configuration variables. The changes are registered into a series of saved states. The one or more computer configuration variables may be restored to a desired saved state using the registry of saved states. In one aspect, the system and method monitors the changes by intercepting system calls, determining which system calls affect the one or more computer configuration variables, and logging the system calls and the results of the system calls that affect the one or more computer configuration variables. A recovery script may be dynamically generated to restore to a saved state.

Abstract: Aspects of the subject matter described herein relate to system state changes. In aspects, a state change monitor detects a state change, determines whether the state change is within a set of state changes that are monitored, and, if so, logs data regarding the state change. The data and any other data needed to rollback the state change is exported to other nodes. The other nodes may store the data for rollback or migration purposes and/or adjust their operation so that they may operate correctly in view of the state change.

Abstract: A method of connecting a card to a terminal including the following steps: a) on receiving corresponding respective commands from the terminal, it modifies the contents of the card memory by provisionally recording in the card memory each of said interdependent items of information without losing prior values corresponding to said items; and then b) the modifications are finalized either by all of them being confirmed or by all of them being discarded.

Abstract: Concepts for enhancing operation of transaction-safe file allocation table systems are described. The concepts include writing a file to non-volatile memory media and rendering an update of file size to the TFAT storage medium; and receiving a request to locate data in a non-volatile memory having a TFAT file management system, selecting a sector of the memory to parse to locate the data, determining when the selected sector is a first sector of a directory or subdirectory of the memory and when determining reveals that the selected sector is a first sector, skipping reading data from the selected sector. The concepts also include flushing a cache and synchronizing FATs.

Abstract: A clustered storage array consists of several nodes coupled to one or more storage systems. The nodes provide a LUN-device for access by a client, the LUN-device mapping to a source logical unit corresponding to areas of storage on the one or more storage systems. A target logical unit corresponds to different areas of storage on the one or more storage systems. The source logical unit is migrated in parallel by the several nodes to the target logical unit.

Abstract: In one embodiment, a system and a method for recovering a device state related to detecting the installation of an application on a computing device, identifying information that pertains to the application, and storing the identified information in nonvolatile memory of the computing device so that the information can be recovered if a reset process is performed.

Abstract: The disclosed systems and methods provide for the protection of protected memory, for example, a hard disk, in a computer system. The systems and methods are configured to re-direct read and write access commands from locations in the protected memory to alternative storage locations. The systems and methods provide the ability for the user to accept or reject any BIOS changes that are to be made to the computing system. In addition, the systems and methods protect against operating system crash due to missing or corrupted files. The systems and methods are additionally operable to recover mistakenly deleted or damaged application data from a hard disk level, as well as to protect the operating system and data of the computing system against virus penetration. In other embodiments, the systems and methods are operable to provide for a security lock to the computing system and its associated data.

Abstract: A method and apparatus for mirroring data between a plurality of sites is provided. At a first site of the plurality of sites, a record is maintained that identifies which changes made to one or more data blocks that are stored at the first site have had associated redo information replicated to the other sites of the plurality of sites. A priority value associated with a transaction that is to be performed at the first site is determined. The transaction specifies a modification to a data block. Thereafter, if the priority value indicates that the transaction should not be lost if the first site becomes inoperable, then the transaction is committed only after the record indicates that all other changes that have updated the data block at the first site have had their respective redo information replicated to the other sites of the plurality of sites.

Abstract: Techniques for restoring parameters and/or values include determining a set of one or more parameters and/or values to be accessed by a user and that are stored in a first memory location, retrieving a duplicate of the set of one or more parameters and/or values to be accessed and storing that duplicate set in another memory location. In the event that one or more of the set of one or more parameters and/or values accessed by a user need to be placed back to their previous state, the duplicate set of one or more parameters and/or values is retrieved to replace one or more of the set of parameters and/or values accessed by the user.

Abstract: A system and method are disclosed for providing a system and method for an efficient lock recovery. In one embodiment of the present invention, a multiple node networked system shares a resource such a shared storage. Among various other aspects of the present invention, when there is a change, such as a server failure, that prompts a recovery, the recovery can be performed in parallel among the nodes. A further aspect of an embodiment of the present invention includes recovering a lock with a higher level of exclusion prior to another lock with a lower level of exclusion.

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: 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 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: The present invention provides a method for providing snapshots of data at different times and for performing rollbacks to a selected snapshot that does not result in any subsequent snapshots being rendered unusable. The method includes a mapping mechanism wherein when a map entry for a block being written to for the first time during a session exists, then another map entry is created and all later sessions are applied to it. When a map entry for the block does not exist, a new map entry is provided and all prior sessions are applied to it.

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 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: Methods and systems for utilizing and recording, writing, or logging data regarding system events occurring within a computer are provided. These systems and methods define a unique erased value, such as the hexadecimal value 0FFh, that identifies unused memory records in an event log. When the computer system receives notification that an event has occurred, it searches for the next memory record containing the erased value in a memory record field designated as a search byte field. Once the unused record is found, the event data concerning the event that occurred is stored in the identified memory record, without updating a pointer to the next unused record. A power event method is provided to update the pointer. A utility application is also provides functions for reading, displaying, erasing, and compiling and displaying statistics concerning the event data in the event log independent of a next unused memory record pointer.

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 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: Disclosed is a technique for processing interruption of an operation that transfers data between a source and a target. An indication that a reverse restore operation has been interrupted is received. It is determined whether designation of at least one of an original source and an original target has been reversed. The settings of one or more relation indicators are also determined. Processing to be performed is identified based on the determinations of whether designations have been reversed and based on the settings of the one or more relation indicators.

Abstract: A system and method are disclosed for providing journal recovery in a multi-node environment which comprises determining whether a block was last updated by a first node; determining whether the block is associated with a lock held by a second node; and writing the block to a final location if the block is not associated with a lock held by the second node. In another embodiment, a system and method are disclosed for providing journal recovery in a multi-node environment which comprises determining whether a block is associated with metadata; determining whether the block is associated with a lock held by a surviving node; and writing the block to a final location if the block is not associated with a lock held by the surviving node.

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: Bulk data is read or written by an application on a first computer system to a file on a second heterogeneous computer system. Alternatively it is read or written as bulk data directly between applications on these heterogeneous systems. Jobs or tasks are started from one system to execute on a second heterogeneous system. Results are then returned to the first system. Checkpointing and later restarting is also initiated from a first system for execution on the second heterogeneous system.

Abstract: A method, system, and computer program product that enable integrated scheduling and management of frozen images for backup and recovery purposes. Frozen images are created, cataloged, and managed in accordance with a backup policy including a schedule for generating frozen images. Minimal data are saved to allow fast synchronization of the persistent frozen images with production data, and frozen images are cataloged in a catalog that may include entries for other types of backups to provide a single source of information for all backups of production data.

Abstract: A remote site stores data received from a currently-used site and transfers the stored data to a proximal site. The proximal site stores the data received from the remote site and transfers the stored data to the currently-used site. The currently-used site crosschecks the data returned from the proximal site against the data transmitted to the remote site, and when the two data do not match each other, transmits the data to the remote site again.

Abstract: The present invention is directed toward a data management appliance and ancillary technologies for replicating data written to a primary storage system. The data management appliance is a random-access storage system that at the logical block level replicates the contents of a primary storage system over time.

Abstract: The location of appropriate undo data necessary for reversing an effect of an operation performed at a computer system is identified during a forward pass through a log. A cycle count can be used to determine if appropriate undo data is stored in an object or is stored in auxiliary storage. If appropriate undo data is stored in an object and the undo data would be potentially lost by processing a redo log entry to modify the contents of the object, the appropriate undo data is copied to auxiliary storage. In some embodiments, a secondary computer system receives log entries from a primary computer system. The secondary computer system can identify undo data necessary to reverse an effect of an operation performed at the secondary computer system from received log entries. Identified undo data can be copied auxiliary storage at the secondary computer system.

Abstract: A method of tracking modifications of specific program objects during the runtime of a computer program, facilitates the creation of general UnDo and ReDo operations, as well as the support of an object-specific UnDo operation. When an object is modified, the object is interrogated to collect information about it and how the modification may be undone. The collected information is stored in a highly unbalanced data-tree structure. Since the interrogation of an object is a characteristic of the programming language, and not necessarily a modification of the program being executed, the present method may be easily applied to different existing programs with minimal, if any, modification to the existing programs.

Abstract: A method and system for processing multi-agent cooperative transactions. A failure detector is provided for detecting whether a failure is an intra-enterprise failure or an inter-enterprise failure. An intra-enterprise failure handler is coupled to the failure detector for performing failure recovery for intra-enterprise failures. Failure recovery for intra-enterprise failures can include identifying the scope of failure recovery within a first enterprise. Once the scope of failure recovery has been identified, a top-down undo operation of sub-transactions in the identified scope may be performed within the first enterprise. An inter-enterprise failure handler is also coupled to the failure detector for performing failure recovery for inter-enterprise failures. Failure recovery for inter-enterprise failures can include identifying the scope of failure recovery in a second enterprise to which a failure in a first enterprise has been transfered.

Abstract: Techniques for executing an atomic transaction include performing a first operation of a first set of operations. The atomic transaction involves the first set of operations for causing changes to a first set of data. A first error that prevents completion of the atomic transaction is detected. In response to detecting the first error, a second set of operations is performed for resolving the first error. It is then determined whether a resolution of the first error is obtained in response to performing the second set of operations. If the resolution is obtained, then execution of the first set of operations is resumed. These techniques allow atomic transactions to be resumed after resolving an error without undoing all the operations accomplished for the transaction at the time the error occurred.

Abstract: If an incidental interruption of power supply occurs in a system, an apparatus and method is provided that a status immediately before the interruption of power supply can be stored. A request for a status-storing process is outputted from an application to a check point manager in a module. A request for an execution of a snap shot output to components, such as the application, a device driver and the like, is outputted to the manager. A sequence at this time is based on an sequence recorded in a status-storing database. The sequence represents a dependence relation between the components. When each component receives the request for the snap shot output, a function existing in a particular address for each component is read out and the component status is outputted as a snap shot file through the manager to a non-volatile memory.

Abstract: Methods for allocating memory for logging data written by a host computer to a source virtual disk and for managing memory allocated to a data log, in a data storage system adapted to maintain redundant data storage sets at a destination location(s) are disclosed. The data storage system maintains a data log that may be activated when a destination volume is inaccessible. During the logging process the system implements an adaptive memory allocation algorithm that adjusts the log memory allocation increment as a function of the velocity of logging data written by the host computer(s). Similarly, during a merge process the system implements an adaptive memory deallocation algorithm that deallocates log memory in response to the velocity of logging data written by the host computer(s) and the velocity of merge data transmitted to the remote system. An amount of memory allocated to logging data may be compared with an amount of memory allocated to corresponding user data and, if greater, the data log terminated.

Abstract: A data storage system adapted to maintain redundant data storage sets at a destination location(s) is disclosed. The data storage system establishes a copy set comprising a source volume and a destination volume. Data written to a source volume is automatically copied to the destination volume. The data storage system maintains a data log that may be activated when the destination volume is inaccessible due to, for example, a malfunction in the destination storage system or in the communication link between the source system and the destination system. I/O commands and the data associated with those commands are written to the data log, and after a destination system becomes available the information in the data log is merged into the destination volume to conform the data in the destination volume to the data in the source volume. The data log competes for disk capacity with other volumes on the system, and log memory is allocated as needed.