Abstract: A computer implemented method, data processing system, and computer usable program code are provided for using identifier virtualization to extend the virtualization capabilities of protocols. A determination is made as to whether a logical entity requires a unique identifier in order to extend a virtualization capability of a protocol. A unique name is assigned that is associated with the logical entity. The unique identifier is requested from a fabric using the unique name. The logical entity is notified that the unique identifier has been established for the logical entity in response to receiving the unique identifier from the fabric. The unique identifier identifies the logical entity within or attached to the fabric.

Abstract: A computer Input/Output system having a fabric, a control unit (CU) and a host computer including a channel, the channel having a channel port connected by a first link to a channel neighbor port of the fabric, and the control unit having a CU port connected by a second link to a CU neighbor port on the fabric. When an error is detected in the link or protocol between the channel and the control unit, error data are reported to the channel by the channel, the channel port, the channel neighbor port, the control unit, the CU port and the CU neighbor port and sent to the channel. The error data are provided to the host computer for analysis.

Abstract: State information is communicated in a network to more efficiently utilize network resources. A first node forms a single extended query requesting state information from at least one logical image of a second node. The extended query is a single query requesting state information for multiple logical images of the first node. The requested state information includes the status of logical paths previously established between the multiple logical images of the first node and the at least one logical image of the second node. Upon sending the extended query to the second node, a single extended response can be formed at the second node having the requested state information.

Abstract: A method, apparatus and program product for the non-disruptive recovery of a single partition in a multipartitioned data processing system. A server contains multiple partitions connected to a single channel adapter which is used to send data and commands to a fabric. A request is sent by the adapter to the well-known address for the fabric. The request includes an identification of the port associated with the partition to be removed. Upon receipt of the request, the fabric removes all resources associated with the port being logged out without affecting ongoing operations in other partitions.

Abstract: A computer Input/Output system having a fabric, a control unit (CU) and a host computer including a channel, the channel having a channel port connected by a first link to a channel neighbor port of the fabric, and the control unit having a CU port connected by a second link to a CU neighbor port on the fabric. When an error is detected in the link or protocol between the channel and the control unit, error data are reported to the channel by the channel, the channel port, the channel neighbor port, the control unit, the CU port and the CU neighbor port and sent to the channel. The error data are provided to the host computer for analysis.

Abstract: The present invention provides a method for managing transmissions to a remote node having a buffer memory for receiving the transmitted packets and means for acknowledging the receipt of the packets. The method provides for a sender to maintain a sense of the availability of buffer memory even when acknowledging messages are lost with minimal impact on performance.

Abstract: State information is communicated in a network to more efficiently utilize network resources. A first node forms a single extended query requesting state information from at least one logical image of a second node. The extended query is a single query requesting state information for multiple logical images of the first node. The requested state information includes the status of logical paths previously established between the multiple logical images of the first node and the at least one logical image of the second node. Upon sending the extended query to the second node, a single extended response can be formed at the second node having the requested state information.

Abstract: The present invention provides a method for fibre channel control units to execute commands locally when a channel sends a repeat execute indicator in conjunction with certain other field settings, wherein the control unit will repeat and chain control words until certain predefined conditions occur.

Abstract: A method, apparatus and program product for the non-disruptive recovery of a single partition in a multipartitioned data processing system. A server contains multiple partitions connected to a single channel adapter which is used to send data and commands to a fabric. A request is sent by the adapter to the well-known address for the fabric. The request includes an identification of the port associated with the partition to be removed. Upon receipt of the request, the fabric removes all resources associated with the port being logged out without affecting ongoing operations in other partitions.

Abstract: A method, apparatus and program product for assigning or confirming multiple address identifications to a single channel adapter. A server contains multiple partitions connected to a single channel adapter which is used to send data and commands to a fabric. A request is sent to the fabric on behalf of each of the partitions, and the fabric assigns or confirms and returns to the adapter, an address identification associated to each partition on whose behalf the request was sent. The assigned or confirmed address is used to communicate between controllers connected to the fabric and the associated partition through the same channel adapter.

Abstract: The present invention provides for a method of transferring information in a network computing system environment. The network environment includes a main storage coupled to a channel subsystem with a plurality of channels which is in processing communication with a control unit capable of coupling to a plurality of input/output devices. At first the packets of data are sent concurrently to and from the main storage. Next execution of certain channel functions are transferred to the control unit so that certain commands can be combined with the data packets in one sequence. Finally only one start data command and only one end command notification needs to be sent before and after a plurality of data packets is transferred respectively.

Abstract: The present invention provides for a method of transferring information in a network computing system environment. The network environment includes a main storage coupled to a channel subsystem with a plurality of channels in processing communication with a control unit capable of coupling to a plurality of input/output devices. First packets of data are concurrently sent to and from the main storage. The operation of certain channel functions are also transferred to the control unit so that each command does not require a command response or an end notification response. Finally by certain commands are combined with the associated data of one or more of the data packets. In one embodiment of the present invention, an optical fabric is also in processing communication with said channels and control unit.

Abstract: Enables an I/O channel program to use IDAWs (indirect data address words) to control data transfers from/to an I/O (input/output) device to/from either or both of ES (expanded storage) and/or system MS (main storage), in which data moved to/from ES does not move through MS. ES and MS are plural electronic storage media in a data processing system, and the I/O device is any I/O device selectable by the system. Intermixing of data transfers between ES and MS may be controlled by a single IDAW list accessed by a channel control word (CCW) in a channel program in a data transfer direction indicated in the CCW without any channel mode change.

Abstract: A channel for a data processing system is provided with a time of day clock that is synchronized with the time of day clock of the associated central processor. Both the central processor and the channel processor record times of particular events, and the channel uses these times to calculate two times called Function Pending and Function Active. Both times begin when the central processor executes an instruction to begin an I/O operation. Function Pending ends when the channel has made successful initial selection. This time shows delays by the channel processor in scheduling the channel control unit, and device resources for I/O operations. Function Active ends at Channel End. A new instruction, Set Channel Monitor, enables or disables these measurements. An information block for each subchannel defines one of several measurement modes for a subchannel or disables the subchannel from measurement.

Abstract: Multiprocessing systems having changeable CPU configurations generate unique changeable identifications (ID's). These are presented by I/O channels over various I/O connection paths, in association with special path defining commands and function data. Related path state indications are stored peripherally in path map tables and define path group associations for sustaining path-independent I/O operations. When a device is reserved via one path in a path group the reserve affiliation is extended automatically (in the path tables ) to each path in the group, thereby rendering each path accessible in a reserved mode. The path defining commands are used for adding paths to, resigning paths from and disbanding groups. Special sensing commands are used for sensing path reservation and grouping states. When a command for adding or resigning a path is presented to a reserved device via one path in a group the reserve is automatically realigned to the enlarged or reduced group.

Abstract: A new instruction called Test Subchannel assures that one processor will not begin an I/O operation with device status information that has been outdated by an operation of another processor. When a device has status to present, a status pending bit and an interruption pending bit are set in the channel subsystem and an interruption request is made. When a processor accepts an interruption, the channel system resets the interruption pending bit but not the status pending bit. The processor that accepts the interruption updates the unit control block (UCB) in main store and resets the status pending bit in the subchannel unless the UCB has been locked by another processor that is starting an I/O operation on the same device. This invention prevents the other processor from operating with outdated status information in the UCB. A processor that has locked the UCB uses Test Subchannel to test the Status Pending bit in the subchannel. If status is pending, the processor executes a routine to update the UCB.

Abstract: Apparatus is provided to permit a processor to interrupt computer input/output operations and later resume the same operations. The apparatus disconnects the input/output device involved in the operations from the channel to free the channel for other operations during the suspension.

Abstract: Program instruction TPI (Test Pending Interruption) and associated data processor sequence controls for its execution enable interruption handling programs to operate in a shortened recursive mode relative to interruptions pending while such programs are in control of a data processor system. Execution of a TPI instruction sets a condition code distinguishing between pendency and non-pendency of a request for interruption in one associated class of interruptions. If an interruption request in that class is pending, the instruction execution controls clear (terminate) it. If more than one request is pending, a selected one is cleared. The selection is based on a predetermined priority ordering. Interruption code information is stored by the execution controls, indicating the source of the cleared request. The interruption handling program branches on the condition code and the interruption code information, to attend to the interruption task associated with the cleared request.