Abstract: Provided are a method, system, and computer program product in which a storage controller receives a first write command with a first token over a first interface from a host computational device. In response to a failure of the first write command in the storage controller, the storage controller retains selected resources for reuse for a retry of the first write command, wherein the retry of the first write command is expected from the host computational device over a second interface that is a slower communication link than the first interface. In response to receiving, by the storage controller, a second write command with a second token over the second interface, wherein the second token is identical to the first token, the storage controller determines that the second write command is a retry of the first write command and reuses the retained selected resources for executing the second write command.

Abstract: A host computational device transmits a first write command with a first token over a first interface to a storage controller. In response to receiving an indication by the host computational device that the first write command has failed in the storage controller, the host computational device transmits a second write command with a second token over a second interface to the storage controller, wherein the second write command is a retry of the first write command that failed, wherein the second token is identical to the first token, and wherein the second interface is a slower communication link than the first interface.

Abstract: Write transfer resource management in a data storage system in accordance with the present description includes overdue write transfer management logic which detects whether or not an established write set has become stale. In one embodiment, a determination is made as a function of whether a write transfer from a host and associated with an established write transfer set is overdue as measured by a time-out period of time. Upon determination that an established write transfer set has become stale, the stale write set is removed and the resources associated with the removed write set are freed for use by other write sets, significantly improving system performance. Other features and aspects may be realized, depending upon the particular application.

Abstract: A host computational device transmits a first write command with a first token over a first interface to a storage controller. In response to receiving an indication by the host computational device that the first write command has failed in the storage controller, the host computational device transmits a second write command with a second token over a second interface to the storage controller, wherein the second write command is a retry of the first write command that failed, wherein the second token is identical to the first token, and wherein the second interface is a slower communication link than the first interface.

Abstract: Provided are a method, system, and computer program product in which a storage controller receives a first write command with a first token over a first interface from a host computational device. In response to a failure of the first write command in the storage controller, the storage controller retains selected resources for reuse for a retry of the first write command, wherein the retry of the first write command is expected from the host computational device over a second interface that is a slower communication link than the first interface. In response to receiving, by the storage controller, a second write command with a second token over the second interface, wherein the second token is identical to the first token, the storage controller determines that the second write command is a retry of the first write command and reuses the retained selected resources for executing the second write command.

Abstract: A storage controller receives a plurality of synchronous writes from a host via a bus interface, wherein each of the synchronous writes is received for writing to a first node and a second node of the storage controller. For each record of a track written to the first node and the second node, an error detecting code is computed on writing the record. In response to determining that computed error detecting codes do not match for any corresponding records of the track in the first node and the second node, an indication of an error is transmitted from the storage controller to the host.

Abstract: Write transfer resource management in a data storage system in accordance with the present description includes overdue write transfer management logic which detects whether or not an established write set has become stale. In one embodiment, a determination is made as a function of whether a write transfer from a host and associated with an established write transfer set is overdue as measured by a time-out period of time. Upon determination that an established write transfer set has become stale, the stale write set is removed and the resources associated with the removed write set are freed for use by other write sets, significantly improving system performance. Other features and aspects may be realized, depending upon the particular application.

Abstract: A storage controller receives a plurality of synchronous writes from a host via a bus interface, wherein each of the synchronous writes is received for writing to a first node and a second node of the storage controller. For each record of a track written to the first node and the second node, an error detecting code is computed on writing the record. In response to determining that computed error detecting codes do not match for any corresponding records of the track in the first node and the second node, an indication of an error is transmitted from the storage controller to the host.

Abstract: Exemplary methods, computer systems, and computer program products for fabricating key fields by a processor device in a computer environment are provided. In one embodiment, the computer environment is configured for, as an alternative to reading Count-Key-Data (CKD) data in order to change the key field, providing a hint to fabricate a new key field, thereby overwriting a previous key field and updating the CKD data.

Abstract: Exemplary methods, computer systems, and computer program products for fabricating key fields by a processor device in a computer environment are provided. In one embodiment, the computer environment is configured for, as an alternative to reading Count-Key-Data (CKD) data in order to change the key field, providing a hint to fabricate a new key field, thereby overwriting a previous key field and updating the CKD data.

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: 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: 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: 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.