Abstract: A method, apparatus, and article of manufacture containing instructions for processing multiple point-in-time consistent data sets. The method consists of creating multiple point-in-time data sets associated with a backup appliance which is associated with backup storage. Upon the transfer of a first update from a primary storage controller to the backup appliance, a determination is made whether the update affects data stored in the backup storage has been unchanged following the creation of the respective data sets. If the update does affect data which is unchanged following the creation of a data set, the current, non-updated data is read from the backup storage. A copy of the current, non-updated data thus read from the backup storage is stored in a storage location which can be one of the data sets or an independent memory location. In addition, pointers are associated with the remaining applicable data sets and directed to the copy at its storage location.

Abstract: Computer networks are provided with a resource efficient ability to generate link performance statistics. To calculate the average link utilization per I/O operation, a first counter accumulates the number of I/O operations processed by a link and a second counter accumulates the time required by the link to complete each I/O operation. The second value is then divided by the first value. The number of operations per second for a link may be computed by dividing the first number by a predetermined period of time and the average number of operations using the link may be computed by dividing the second number by the predetermined period of time. A third counter may be employed to accumulate the number of bytes transferred by a link during each I/O operation. Then, average size of an I/O operation may be computed by dividing the third number by the first number and the average bandwidth per link operation may be computed by dividing the third number by the predetermined period of time.

Abstract: A data storage device for recording to and reading from magnetic thread includes a head assembly having an opening through which the magnetic thread passes. Transducing elements are positioned around the inner surface of the opening and interact with longitudinally-extending parallel tracks formatted around the surface of the magnetic thread. If the number of tracks is greater than the number of transducing elements, the transducing elements may be rotatable about the magnetic thread to position the transducing elements to interact with other tracks. The head assembly may open to aid positioning the magnetic thread within the opening in the head assembly during loading. If desired, multiple head assemblies may be placed in the thread path to improve data throughput. The magnetic thread may be formed with a non-circular cross-section and the opening in the head assembly may have a corresponding cross-section to reduce twisting of the magnetic thread as it passes through the opening.

Abstract: A method of, apparatus for, or storage device medium having instructions for publishing a first notification within a data processing system where the data processing system comprises a first source generating the first notification, a first destination device, and a second destination device. The source may be a storage unit, a printer, a processing unit, or any other device which is a component of the data processing system. The destination device is typically a monitor, a workstation, a computer, a PC, or other input/output type workstation. The method comprises of having the first destination device subscribe to receive notifications from the first source. In addition, the second destination device subscribes to receive the notifications serially republished from the first destination device. Upon the publication of a notification from the first source to the first destination device, the first destination device will publish the notification to the second destination device.

Abstract: A method of storing data to one of a first or second storage device associated with a data storage system where each storage device provides for the redundant access to and storage of data within the same logical data volumes. The method of storing data consists of defining a storage construct which will direct the performance of a specific storage function. The storage construct is then associated with a logical data volume. The method further consists of mounting the logical data volume residing on one of the two storage devices and executing a storage function in accordance with the storage construct. The storage construct may be defined by a command issued by a host associated with the data storage system. Alternatively, the storage construct may be defined by a user of the data storage system through a user interface.

Abstract: Method, apparatus and program product are provided for the invalidation of faulty metadata in a storage controller coupled to a host device. Faulty metadata may include metadata which no longer matches the associated customer data tracks stored on a DASD or other storage device. When faulty metadata is detected, metadata tracks are selected to be invalidated. A command is received through a host interface, without the controller being taken off-line from the host, and the specified metadata tracks are invalidated. Subsequently, the invalidated metadata tracks are rebuilt. The disclosed method, apparatus and program product invalidate the faulty metadata with reduced impact on normal host/controller I/O operations.

Abstract: Method, apparatus and computer program product are provided to increase the efficiency of copy operations in a data storage system. Multiple virtual storage controllers are each in communication with a host device and to two virtual storage servers. Both virtual storage servers are attached to a respective automated storage library. Each controller includes a copy queue. After directing that a volume of customer data be stored through one of the servers on media in the associated library, an initiating controller queues in a copy queue a request to copy the volume to the other library. If the request is not processed by the initiating controller within a very short period, the initiating controller broadcasts the copy request to the other controllers. Preferably, the copy request is transmitted first from the initiating controller to a routing device in one of the servers which broadcasts the request to each other controller. The copy request is queued in a copy queue of each other controller.

Abstract: A cartridge handling system and method are provided to initialize a data storage cartridge having rewritable media and a cartridge memory for tamper resistant write once recording. During initialization of the cartridge for write once recording, selected data set information table fields of each data set are scrambled. The scrambling algorithm may employ a random number generator seeded with a unique cartridge identifier. The fields thus becomes unreadable if the unique identifier is changed, such as if the cartridge memory of the cartridge has been altered or replaced.

Abstract: A method and user interface are provided for independently and conveniently scaling y-values of multiple data sets whereby the data sets may be plotted against a common y-axis and provide satisfactory variability. A multiplier is selected by which data points in a data set are multiplied, allowing plots of multiple data sets to be graphed against a common range of y-axis values. The initial multiplier may be calculated and selected automatically by the computer on which the graphing is performed or may be manually selected by a user. If the results of the graphing are not satisfactory to the user, the user may change the multiplier for any data set. A spin button may be provided to enable the user to easily increment or decrement a multiplier in predefined steps, such as by factors of 10. Additionally, a computer-generated indicator may be displayed to assist the user in selecting a different multiplier.

Abstract: Disclosed are a system, a method, and a computer program product to provide improved error handling in an embedded system. When the embedded system encounters a fatal error, information pertaining to the error is saved and an indication that the error has occurred is also saved. The embedded system resets itself to allow normal operation to resume. Before or after the reset, the embedded system sets an indication of the prior error so that a human or a machine will be alerted to the fact that the embedded system had encountered the error. At some point in time, the error information may be retrieved, collected or sent for post error analysis. The error flag and/or error status is then cleared to remove the current error condition and/or allow a subsequent error to be managed.

Abstract: Methods, system and computer program product are provided for managing and tracking on-demand removable, serialized data resources, such as storage frames, storage drives and media, in an automated data storage library. Storage frames, data storage drives and media are tracked by the automated data storage library to prevent use or misappropriation until authorized. Alternatively, or additionally, the data storage drives may be prevented from being used until instructed to do so. In addition, the media may be prevented from being used until modification is made to the medium or cartridge memory of the data storage media.

Abstract: A data storage control unit is coupled to one or more host devices and to one or more physical storage units, the storage control unit configured as a plurality of clusters. Each cluster includes cache memory and often non-volatile storage (NVS). The storage control unit receives and processes write requests from the host devices and directs that data updates be temporarily stored in the cache in one cluster and copied to the NVS of the other cluster. The data updates are subsequently destaged to the logical ranks associated with each cluster. During an initial microcode load (IML) of the storage controller, space in the cache and NVS of each cluster is allocated to buffers with the remaining cache and NVS space being allocated to customer data. After an IML has been completed, the size of the buffers become fixed and no further buffer allocation may occur.

Abstract: A data storage control unit is coupled to one or more host devices and to one or more physical storage units. Data is stored in one of the storage units and, for data integrity, copied to another storage unit. An updated state of the copy process (metadata) is maintained and updated in metadata tracks in a memory of the storage controller and periodically destaged to corresponding metadata tracks of a storage unit. If the copy process is interrupted, such as by a power failure, an error handling routine commences. Track state fields associated with each in-memory metadata track are initialized to an ‘invalid’ state and background staging of metadata tracks from the storage unit to the memory. After a track is staged, the associated track state field is changed to a ‘valid’ state. If a request is received to access a track of copy state data and the track has been staged (as indicated by the state of the associated track state field), the track is accessed.

Abstract: A system, method and computer program product are provided to improve the efficiency of the transmission of consistency groups across multiple storage components by ensuring that volume transactions are evenly allocated among backup components. Each volume is initially assigned to a specified backup component. Once a color period begins, volume transactions are transmitted to the assigned backup component. Each backup component accumulates data transfer information for its assigned volumes throughout at least a portion of the color period and calculates a new volume assignment for the next color period. Before the start of the next color period, a captain storage controller transmits any new assignments to the backup components. During a next color period, the process is repeated using the new assignments.

Abstract: A method, system, and article of manufacture for recovering from a track format error detected by a host computer associated with a storage controller associated with a storage disk array. The recovery method begins with saving a copy of the track format information associated with the data track that triggered the track format error in a predetermined location. Next, the track format information associated with the data track that caused the error is invalidated and the subject data is restaged. Subsequently, the restaged data is compared to the saved copy of the track format information to determine if the track format error exists with respect to the restaged data. If the track format error is detected with respect to the restaged data, the method further consists of reconstructing the data, preferably by performing a reconstruct read recovery.

Abstract: A method, system and computer program product are provided to allow the status of components obtained through JMX queries to be loaded asynchronously in web content such that the status value of each component is displayed as soon as it becomes available, without having to wait for the completion of any other query.

Abstract: Methods, system and computer program product are provided to improve the efficiency of data transfers in a PPRC environment. Any or all of three features may be implemented, each of which reduces the number of round trips required for the exchange of handshaking, data and control information. A first feature includes disabling the “transfer ready” acknowledgment which normally occurs between a primary storage controller and a secondary storage controller. A second feature includes pre-allocating payload and data buffers in the secondary storage controller. A third feature includes packaging write control information with a write command in an extended command descriptor block (CDB). Such a step eliminated the need for a separate transmission of the write control information. The CDB is transmitted along with a data block from the primary storage controller to the secondary storage controller and placed in the respective, pre-allocated buffers. Data may also be pipelined to the secondary.

Abstract: Method, system and computer program product are provided to increase the efficiency of the development of Java Enterprise Edition (J2EE) applications. A project may be divided into modules which may be developed by independent teams. The files within each module are classified as independent of resources in other modules or dependent. Independent files may be packaged into a single, integrated web application archive (WAR) file without further processing. Corresponding dependent files are compared and any conflicts are resolved. The resulting files may then be packaged into the WAR file.

Abstract: Methods, system and computer program product are provided to configure a path between nodes through a fabric in a fibre channel storage area network (SAN). A node name is provided for a target node on the SAN and a port name is provided for each port in the target node. A relationship is established in a data structure between each port name and a slot in which each port is physically located in the target node. Prior to configuring a path between a source node and a port in the target node, the ports which are physically connected and logged in to the fabric are identified by port address. The port names corresponding to the port addresses are then identified. The port names are used to generate interface_ids of the ports corresponding to the physical slots in which the ports are located. A data structure is created to maintain the relationship between interface_ids and port names.

Abstract: Method, system and computer program product are provided to improve the reliability of data transfers from RAID systems. Although some read errors may be detected by the RAID controller, other errors may not be; undetected errors may affect the integrity of the data. In accordance with the present invention, the host or client issues a first command to the RAID controller to read specified data. After the RAID controller obtains the data from the RAID drives and transmits it to the host, the host verifies the data to detect any errors. If an error is detected by the host, the host issues a second command to the RAID controller to reconstruct the specified data, rather than merely re-read the data. The reconstructed data is then transmitted to the host. Consequently, previously undetected and uncorrected errors may be detected and corrected by the host.