Abstract: The present invention provides a system for managing a complex, the system comprising a discovery and monitoring subsystem, a reference model store subsystem, a reference model transcription subsystem, a reference model generation subsystem, a model comparator subsystem, a reference model update subsystem, a nonconformance visualization subsystem, a conformance monitoring subsystem, a change procedure generator subsystem, and a change automation subsystem.

Abstract: This invention is a system and method for performing a data management function using correlated data obtained from analyzing work performed on data stored in a data storage system.

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

Abstract: In one embodiment of the present invention, a memory controller is provided that includes both a first processor and a second processor. If a memory device controlled by the controller indicates to the controller that an error condition exists in the device, either the first processor or the second processor is selected to handle the error condition. If the first processor is selected to handle the error condition, the first processor handles the error condition according to one or more statically preprogrammed error handling routines. Conversely, if the second processor is selected to handle the error condition, the second processor handles the error condition according to one or more dynamically programmable error handling routines.

Abstract: A system for providing high speed external backup and restoration of data in a data storage system. Individual data objects are backed up in logical order on backup media such as magnetic tape so that they may be retrieved individually. Minimized descriptions of backed up data are transmitted between the host and backup systems to control high speed transfer of data between data servers and backup devices on a separate data channel. The descriptions are manipulated by the backup system to comply with formats of any number of host systems and data storage systems and to efficiently map the backed up data onto the backup devices. The system also provides for restoration of data to the data storage system by using a host system to pre-allocate space for the restored data, obtaining mapping information for the allocated space from the host system, and then directly writing the restored data into the allocated space, based on the mapping information.

Abstract: A digital data storage system comprises a storage device, a descriptor memory and a control device. The storage device stores a series of records, the records being organized in a plurality of tracks, each track being associated with one of a plurality of cylinders. The descriptor memory stores a descriptor associated with storage device. The descriptor contains selected information relating to the records stored by the at least one storage device. Each descriptor includes a plurality of cylinder portions each configured to store selected information relating to a respective one of the cylinders in the storage device. Each cylinder portion, in turn, includes a plurality of track descriptors each configured to store selected information relating to a respective one of the tracks in the respective cylinder. The storage device also stores the descriptor associated therewith, the cylinder portions of the descriptor being augmented with additional information relating to the respective ones of the cylinders.

Abstract: This invention is a system and method for replaying workload data that may be accessed in a data storage environment and then replayed for testing or other reasons. The invention has the capability to extract a trace of all I/Os to a data storage system for an extended period of time and then replay these I/Os back to that or another system. Variables may also be manipulated though the play back system to increase testing flexibility at a lower cost than actually introducing new physical variables.

Abstract: In a system that includes a back-up subsystem comprising back-up media, a mass storage subsystem connected to the back-up subsystem, and a host connected to the mass storage subsystem, the mass storage subsystem, as master and independent of the host, requests the restore operation by providing to the back-up subsystem, as slave, data identifiers identifying multiple data items to be transferred during the restore operation. The back-up subsystem determines its preferred ordering for retrieval of the requested plurality of data items from the back-up media. The back-up subsystem provides the requested data items to the mass storage subsystem in the determined preferred order in a plurality of iterations, each iteration identified by a data item identifier for the data item to be transferred in the current iteration.

Abstract: This invention is a system and method for preparing workload data that may be accessed in a data storage environment and then replayed for testing or other reasons. The invention has the capability to prepare a trace of I/Os to a data storage system for an extended period of time for replaying these I/Os back to that or another system. Variables may also be manipulated through a preparation process and is particularly useful for customizing benchmarking tests, or consolidation, or trouble-shooting, or capacity planning.

Abstract: Queued lock services for managing a shared resource in a data processing system include a cooperative lock override procedure. On detecting a protocol failure by another processor, the detecting processor confirms that the failing processor is the lockholder and passes the lock to the next requestor in the queue.

Abstract: The present invention is a system and method for providing clarity and simplicity to the task of screening for errors occurring in a data storage system and improving the effectiveness of the response to these errors. The system and method includes and employs a graphical user interface (GUI) for providing clarity and simplicity. Also by constraining entry texts into a controlled entry field, the likelihood of text-entry errors are greatly reduced. Further by providing menu options, simplicity and clarity are improved while likelihood of text-entry errors are also further reduced. Text-entry error checking tools are also provided to further decrease the probability that such errors will occur. The system and method employ a mechanism to allow for remote error screening and responding to the error from a remote location also.

Abstract: There is disclosed a client-server configuration including a peripheral device wherein multiple servers interface with both the client and the peripheral. Management software for determining the operating state of the peripheral, known as server agent software, is employed in the multiple servers under control of the client. In order to avoid conflicting information reflecting multiple operating states of the peripheral, a primary/secondary algorithm is used to enable the client to determine only one peripheral operating state while allowing each server to also verify its connectivity to the peripheral and to the client.

Abstract: This invention is configured to create and use a special data structure containing a data storage device's identification information for a storage device that will be duplicated. Upon such duplication, the special data is stored in a predetermined location on another device receiving the copied data and a flag bit is set to indicate whether or not the information in the data structure should be used to respond to a host inquiry regarding the identification of the storage device. Without reconfiguring the host's operating software, the system employs a method to respond to and satisfy a host inquiry for the storage device's identification information by employing the special data structure. This is done to avoid host conflict errors that might result from a conflict between identification information being replicated from the storage device and the other storage device to where its data is copied.

Abstract: An arrangement is disclosed for use in connection with a host computer connected to a mass storage subsystem, the mass storage subsystem storing information for use in connection with processing of at least one program by the host computer. The arrangement comprises a program input/output interface, a mass storage subsystem interface and a file system control. The program input/output interface is configured to receive program input/output read and write requests from a program, each program input/output read and write request initiating an input/output operation in connection with information stored on a mass storage subsystem. The mass storage subsystem interface is configured to facilitate communications with the mass storage subsystem, including transferring a storage subsystem input/output read and write request thereto and receiving information therefrom.

Abstract: A lock for managing shared resources in a data processing system enables a requesting processor, in a signal atomic transaction, to validate the main lock data structure, request a lock, take the lock and establish a lock mode if successful, or establish its place in a queue of requesters for subsequent locks on the shared resource if unsuccessful.

Abstract: This invention is a system and method for efficiently carrying out a restore operation in a data storage environment. The present invention is a system and method for restoring data in a manner that reduces wait time of associated resources. Logic, which is part of the invention, determines whether a restore is in progress when an application on a computer system is involved in trying to perform an I/O operation on a track of data. A protective scheme is used to keep such data from being updated while the restore is taking place. Importantly the system resources do not have to wait for the restore to complete to carry out I/O operations, which are accounted for separately from the data itself and then a synchronization occurs following completion of the restore.

Abstract: A management information transfer system is disclosed for use in connection with a network including one or more host computers and a mass storage subsystem interconnected by a plurality of switching nodes, the management information transfer system being configured to transfer processed management information to a management service center located remotely from the network. The management information transfer system includes a management server that is configured to receive management information from the switching nodes, and possibly the host computers, which may be directed to failures or other malfunctions in connection with their operations. The management server is configured to perform a filtering operation in connection with the management information that it receives from the switching nodes using filtering policies that may be established by, for example, a network administrator.

Abstract: A queued, multimodal, fault-tolerant lock mechanism for managing shared resources in a data processing system is provided. Lock override procedures are selectively associated with certain lock modes.

Abstract: A system and method for determining whether activity graphs (hereinafter “graphs”) for logical volumes of data storage are correlated. A number of correlation criteria are applied to the graphs, including the area ratio criteria determines whether an area ratio described by the graph is at least as great as a predetermined value; the peak ratio criteria indicates that one graph is correlated to another graph if a peak ratio described by the two graphs is as large as a predetermined peak ratio value; and the sharp peak criteria indicates in the event that one graph is correlated to another graphs having at least one coincidental peak. Different combinations of all or some of the disclosed correlation criteria and the traditional correlation coefficient may be used to determine whether graphs of logical volumes are correlated, the level of correlation, and how “strong” of a correlation exists between the graphs.