Abstract: A method for processing a point-in-time copy of data associated with a logical storage volume where the data to be copied is stored in a striped or parallelized fashion across more than one physical source volume. The method includes receiving a point-in-time copy command concerning a logical volume and distributing the point-in-time copy command in-band to each of the physical source volumes containing a portion of the striped data. The method also includes establishing a point-in-time copy relationship between each physical source volume and one of a corresponding set of multiple physical target volumes. The method further includes copying the data stored on each physical source volume to the corresponding physical target volume. The in-band copy command and the striped data may be distributed over I/O channels between a server and the physical storage and processed sequentially.

Abstract: A feature key is provided to enable a specific feature in a target system, such as an IBM® Enterprise Storage Server®. The key includes fields identifying at least a portion of a serial number of the target system, identifying the feature on the target system to be enabled, and identifying a quantity associated with the feature to be enabled. Including the serial number ensures that the feature key will enable the feature on only the designated system and including the quantity ensures that only the quantity (of storage space, for example) paid for by the customer will be enabled. Additional fields may also be included identifying a storage architecture on which the feature is to be enabled, identifying a machine on which the feature is to be enabled, and identifying a sequence of prior feature keys generated for the feature on the target system.

Abstract: Real-time notification is provided of an event which has occurred in a computer-related device. Upon the occurrence of an event, a record of the event is stored in a buffer, such as a Really Simple Syndication buffer, associated with the device. The buffer is updated based on indications and other events noted by a CIM agent in the device. One of a series of regular requests is received from an open browser window on a user computer, the request inquiring about any record of the event stored in the buffer. In response to the request, the record of the event is transmitted to an HTML event element in a page of the browser window whereby the record of the event is inserted into the HTML element and displayed in the browser window.

Abstract: A RAID system is provided for detecting and correcting dropped writes in a storage system. Data and a checksum are written to a storage device, such as a RAID array. The state of the data is classified as being in a “new data, unconfirmed” state. The state of written data is periodically checked, such as with a timer. If the data is in the “new data, unconfirmed” state, it is checked for a dropped write. If a dropped write has occurred, the state of the data is changed to a “single dropped write confirmed” state and the dropped write error is preferably corrected. If no dropped write is detected, the state is changed to a “confirmed good” state. If the data was updated through a read-modified-write prior to being checked for a dropped write event, its state is changed to an “unquantifiable” state.

Abstract: Methods, systems, computer program products and methods for deploying computing infrastructure for managing metadata in a storage subsystem are provided. A first metadata track is staged from disk storage to a cache storage after which a journal entry is stored in a nonvolatile storage (NVS). The journal entry includes an opcode and update data for the track. The opcode identifies the type of update to be performed and the number of tracks to be updated in the operation. Each of the other metadata tracks is staged and a corresponding journal entry stored. The journaled updates are then applied to the respective metadata track in the cache storage and the tracks destaged from cache to the disk storage.

Abstract: A system is provided to encode data for recording onto media whereby modulation and linear constraints from a concatenated code or product code are imposed. A first array of unencoded user data is generated. Each row is modulation encoded to enforce a first modulation constraint; the array is transformed into a second array which is transformed into a third array having predetermined empty locations in each column interleaved with the modulated data. A C2-parity byte is computed for at least some of the empty locations of the third array and a fourth array is generated. C1-parity symbols in each row are computed, generating a fifth array. A second modulation constraint is enforced on each C1-parity symbol in each row of the fifth array, generating a sixth array. The rows of the sixth array are assembled with header and sync fields for recording onto a recording media.

Abstract: For writing data to multi-track tape, a received data set is received and segmented into unencoded subdata sets, each comprising an array having K2 rows and K1 columns. For each unencoded subdata set, N1-K1 C1-parity bytes are generated for each row and N2-K2 C2-parity bytes are generated for each column. The C1 and C2 parity bytes are appended to the ends of the row and column, respectively, to form encoded C1 and C2 codewords, respectively. All of the C1 codewords per data set are endowed with a specific codeword header to form a plurality of partial codeword objects (PCOs). Each PCO is mapped onto a logical data track according to information within the header. On each logical data track, adjacent PCOs are merged to form COs which are modulation encoded and mapped into synchronized COs. Then T synchronized COs are written simultaneously to the data tape where T is the number of concurrent active tracks on the data tape.

Abstract: 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 and computer program product are provided to encode data for recording onto media whereby modulation and linear constraints from a concatenated code or product code are imposed. A first array of unencoded user data is generated. Each row is modulation encoded to enforce a first modulation constraint; the array is transformed into a second array which is transformed into a third array having predetermined empty locations in each column interleaved with the modulated data. A C2-parity byte is computed for at least some of the empty locations of the third array and a fourth array is generated. C1-parity symbols in each row are computed, generating a fifth array. A second modulation constraint is enforced on each C1-parity symbol in each row of the fifth array, generating a sixth array. The rows of the sixth array are assembled with header and sync fields for recording onto a recording media.

Abstract: Method, apparatus and computer program product adjust gain in a read channel of a magnetic media data storage device. A digital signal sample having a data-dependent noise component is received. A gain value, stored in a location in a gain table, is selected in a data-dependent manner. The gain of the signal sample is adjusted in response to the selected gain value. A bit pattern is detected from the gain-adjusted signal sample and a data output signal is output based upon the detected bit pattern.

Abstract: An initial program load (IPL) of a logical partition (LPAR) is managed by establishing a logical path to the LPAR from a storage controller. When a notice is received by the storage controller from the LPAR that the IPL has commenced, the LPAR address is stored in a data structure. After the storage controller initiates a pack change state interrupt, the stored address is compared with the addresses in a list of all LPARS to which the interrupt is directed. If the list of addresses includes the stored address, the stored address is removed from the list. Thus, the pack change state interrupt is transmitted only to the addresses in the list, leaving the LPAR to complete the IPL without interruption. After the storage controller receives a notice from the LPAR that the IPL has completed, the address of the LPAR is removed from the data structure.

Abstract: The present invention provides a novel method for determining the mechanical properties of the surfaces of materials including thin films. Generally, the method is comprised of laterally scanning the surface of the film with an array of cantilever tips varying temperature, load and time to obtain a measurement of mechanical properties, such as hardness and glass transition temperature. The method can be used to obtain mechanical properties of films that would otherwise be unobtainable using standard methods.

Abstract: An initial program load (IPL) of a logical partition (LPAR) is managed by establishing a logical path to the LPAR from a storage controller. When a notice is received by the storage controller from the LPAR that the IPL has commenced, the LPAR address is stored in a data structure. After the storage controller initiates a pack change state interrupt, the stored address is compared with the addresses in a list of all LPARS to which the interrupt is directed. If the list of addresses includes the stored address, the stored address is removed from the list. Thus, the pack change state interrupt is transmitted only to the addresses in the list, leaving the LPAR to complete the IPL without interruption. After the storage controller receives a notice from the LPAR that the IPL has completed, the address of the LPAR is removed from the data structure.

Abstract: A diversionary device has a housing having dimensions which are selected such that when the device is thrown or dropped, the device will come to rest only on one of its two primary sides. Each primary side has a circular dispersion port formed therethrough. The device includes means for blocking the first dispersion port if the device comes to rest on the first primary surface and for blocking the second dispersion port if the device comes to rest on the second primary surface. A firing mechanism is operable to discharge an ignitable composition out of a removable cartridge within the housing. The ignitable composition is discharged through the first dispersion port when the device rests on the second primary side and through the second dispersion port when the device rests on the first primary side. The composition then forms a cloud above the device and may be ignited.

Abstract: A weighted combining scheme exploits information from two servo channels operating in parallel. A timing-based servo module comprises two synchronous servo channels coupled respectively to receive two digital servo signals read from a data tape. Both channels have outputs for an unweighted parameter estimate and for a measure of the channel reliability. A weight computation module provides first and second weight signals using the measures of channel reliability from the servo channels. An offset computation module provides first and second offset terms which are summed with the unweighted parameter estimates. Multiplying nodes receive the unweighted parameter estimates and the weight signals and outputs offset weighted parameter estimates. A summing node receives the offset weighted parameter estimates and outputs a combined offset weighted parameter estimate to a servomechanism.

Abstract: A longitudinal position (LPOS) word L(n) is encoded with error correction capability. The LPOS word includes a plurality of LPOS symbols L0(n) through Lk(n) calculated as L ? ( n ) = ? i = 0 5 ? L i ? ( n ) ? 14 i and representing a longitudinal position of a magnetic tape relative to a tape head in a tape storage system. A word type is determined in response to at least one of the plurality of LPOS symbols and, in response to the determined word type, at least one formatted symbol F(n) is generated from the plurality of LPOS symbols L(n). At least one parity symbol P(n) is generated from the formatted symbol F(n). The formatted and parity symbols are communicated to a servo channel of the tape storage system to be recorded onto a servo track of the magnetic tape. Adding redundancy to LPOS words provides the capability of correcting multiple bit errors without increasing the LPOS word length.

Abstract: Method, system and computer program product are provided for detecting and correcting dropped writes in a storage system. Data and a checksum are written to a storage device, such as a RAID array. The state of the data is classified as being in a “new data, unconfirmed” state. The state of written data is periodically checked, such as with a timer. If the data is in the “new data, unconfirmed” state, it is checked for a dropped write. If a dropped write has occurred, the state of the data is changed to a “single dropped write confirmed” state and the dropped write error is preferably corrected. If no dropped write is detected, the state is changed to a “confirmed good” state. If the data was updated through a read-modified-write prior to being checked for a dropped write event, its state is changed to an “unquantifiable” state.

Abstract: Methods are provided for detecting and correcting dropped writes in a storage system. Data and a checksum are written to a storage device, such as a RAID array. The state of the data is classified as being in a “new data, unconfirmed” state. The state of written data is periodically checked, such as with a timer. If the data is in the “new data, unconfirmed” state, it is checked for a dropped write. If a dropped write has occurred, the state of the data is changed to a “single dropped write confirmed” state and the dropped write error is preferably corrected. If no dropped write is detected, the state is changed to a “confirmed good” state. If the data was updated through a read-modified-write prior to being checked for a dropped write event, its state is changed to an “unquantifiable” state.

Abstract: When a VTOC and a VVDS are established for information used to access data sets of a volume, unused space remains in both structures. The data sets, VTOC and VVDS are stored on a recordable medium. For VSAM data sets, other, vital information about the data set is also stored in the VTOC; for non-VSAM data sets, vital information about the data set is also stored in the VVDS. If the VOTC entry of a non-VSAM data set becomes corrupted, the vital information in the VVDS may be used to access the stored data set. Similarly, If the VVDS entry of a VSAM data set becomes corrupted, the vital information in the VTOC may be used to access the stored data set.

Abstract: A method is provided for determining the length of node-to-node links in a computer network. The method includes measuring the forwarding time for each node-to-node link in the network, eliminating queuing time from each forwarding time measurement, determining and subtracting store-forward time from each forwarding time measurement, determining and subtracting execution time from each forwarding time measurement to obtain a propagation time for a signal being transmitted on each node-to-node link and, based upon the propagation time for each node-to-node link, calculating a length of each node-to-node link. A network map may also be derived by identifying internal nodes in the network, translating each store-forward time into a hop count, constructing a connectivity map of the network including a connection map of internal nodes and superimposing the calculated link lengths onto the connectivity map to determine cable length between any internal nodes with more than two connections.