Abstract: An apparatus, system, and method are disclosed for device level enablement of a communications protocol. An adapter compatibility module determines an adapter compatibility status for a plurality of host adapters. A positive adapter compatibility status indicates that each host adapter in the plurality of host adapters is compatible with a communications protocol. A processor compatibility module determines a processor compatibility status for one or more processors. The one or more processors coordinate data transfers to and from the plurality of host adapters. A positive processor compatibility status indicates that each of the one or more processors is compatible with the communications protocol. A compatibility summary module determines a compatibility summary for the plurality of host adapters and the one or more processors.

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: An apparatus, system, and method are disclosed for device level enablement of a communications protocol. An adapter compatibility module determines an adapter compatibility status for a plurality of host adapters. A positive adapter compatibility status indicates that each host adapter in the plurality of host adapters is compatible with a communications protocol. A processor compatibility module determines a processor compatibility status for one or more processors. The one or more processors coordinate data transfers to and from the plurality of host adapters. A positive processor compatibility status indicates that each of the one or more processors is compatible with the communications protocol. A compatibility summary module determines a compatibility summary for the plurality of host adapters and the one or more processors.

Abstract: A method of performing an input/output operation includes: generating by a channel subsystem at least one command message including one or more device command words (DCWs), at least one DCW including a data count and a suppress-length indication (SLI) configured to instruct a control unit whether to continue to perform the I/O operation in response to an incorrect length condition; forwarding the at least one command message to the control unit; receiving an incorrect length (IL) value from the control unit and storing an IL indicator in a subchannel-status word, the IL indicator representing the IL value, the IL value being a first IL value in response to a first SLI value and the data count not matching the amount of data required, the IL value being a second IL value in response to a second SLI value and the data count not matching the amount of data required.

Abstract: A computer program product is provided for performing an input/output (I/O) processing operation at a host computer system. The computer program product is configured to perform: obtaining a transport command word (TCW) at a channel subsystem for an I/O operation, the TCW including an address of a transport command control block (TCCB) having a transport command area (TCA) configured to hold a first plurality of device command words (DCW) and control data associated with respective DCWs, the first plurality of DCWs including a transfer TCA extension (TTE) DCW that specifies a TCA extension, the TCA extension configured to hold one or more DCWs and control data associated with respective DCWs; gathering the TCCB from one or more locations specified in the TCCB address and transferring the TCCB to the control unit; gathering the TCA extension specified by the TTE DCW; and transferring the TCA extension to the control unit.

Abstract: A method of performing an input/output operation includes: generating by a channel subsystem at least one command message including one or more device command words (DCWs), at least one DCW including a data count and a suppress-length indication (SLI) configured to instruct a control unit whether to continue to perform the I/O operation in response to an incorrect length condition; forwarding the at least one command message to the control unit; receiving an incorrect length (IL) value from the control unit and storing an IL indicator in a subchannel-status word, the IL indicator representing the IL value, the IL value being a first IL value in response to a first SLI value and the data count not matching the amount of data required, the IL value being a second IL value in response to a second SLI value and the data count not matching the amount of data required.

Abstract: A computer program product is configured for performing a method including: generating at least one command message by a channel subsystem of the host computer system, the at least one command message including one or more device command words (DCWs), wherein at least one DCW of the one or more DCWs includes a suppress-length indication (SLI) configured to instruct a control unit to continue to perform the I/O operation in response to the control unit detecting that the data count does not match an amount of data required; receiving an incorrect length (IL) value, the IL value being a first IL value in response to the SLI being a first SLI value and the data count not matching the amount of data required; and responsive to receiving the IL value from the control unit, storing an IL indicator in a subchannel-status word.

Abstract: A computer program product is configured for performing a method including: generating at least one command message by a channel subsystem of the host computer system, the at least one command message including one or more device command words (DCWs), wherein at least one DCW of the one or more DCWs includes a suppress-length indication (SLI) configured to instruct a control unit to continue to perform the I/O operation in response to the control unit detecting that the data count does not match an amount of data required; receiving an incorrect length (IL) value, the IL value being a first IL value in response to the SLI being a first SLI value and the data count not matching the amount of data required; and responsive to receiving the IL value from the control unit, storing an IL indicator in a subchannel-status word.

Abstract: A computer program product is configured for performing a method including: receiving at least one command message specifying an I/O operation at a control unit from a channel subsystem, the at least one command message including one or more device command words (DCWs) having a data count and a suppress-length indication (SLI), the SLI configured to instruct the control unit whether to continue to perform the I/O operation in response to the control unit detecting an incorrect length condition; processing at least one of the one or more DCWs; and returning a transport response message including an incorrect length (IL) value, the IL value being a first IL value in response to the SLI being a first SLI value and the data count not matching the amount of data required, the IL value being a second IL value in response to the SLI being a second SLI value and the data count not matching the amount of data required.

Abstract: A computer program product is provided for performing an input/output (I/O) processing operation at a host computer system. The computer program product is configured to perform: obtaining a transport command word (TCW) at a channel subsystem for an I/O operation, the TCW including an address of a transport command control block (TCCB) having a transport command area (TCA) configured to hold a first plurality of device command words (DCW) and control data associated with respective DCWs, the first plurality of DCWs including a transfer TCA extension (TTE) DCW that specifies a TCA extension, the TCA extension configured to hold one or more DCWs and control data associated with respective DCWs; gathering the TCCB from one or more locations specified in the TCCB address and transferring the TCCB to the control unit; gathering the TCA extension specified by the TTE DCW; and transferring the TCA extension to the control unit.

Abstract: A computer program product is configured for performing a method including: receiving at least one command message specifying an I/O operation at a control unit from a channel subsystem, the at least one command message including one or more device command words (DCWs) having a data count and a suppress-length indication (SLI), the SLI configured to instruct the control unit whether to continue to perform the I/O operation in response to the control unit detecting an incorrect length condition; processing at least one of the one or more DCWs; and returning a transport response message including an incorrect length (IL) value, the IL value being a first IL value in response to the SLI being a first SLI value and the data count not matching the amount of data required, the IL value being a second IL value in response to the SLI being a second SLI value and the data count not matching the amount of data required.

Abstract: Deleting a data volume from a storage system and freeing its storage space to make it available to be allocated to a new volume is accomplished by only zeroing associated metadata for the tracks contained in the freed storage space which is then reused in a new volume allocation and an attempt is made by the new volume to read a first record R0 of a track. A determination is made as to whether a first user record R1 of the volume is stale If the first record R0 is stale. If record R1 is stale, the metadata or track format description (TFD) is modified whereby the entire track is indicated as being uninitialized and the first record R0 is uninitialized. If record R1 is not stale, the first record R0 is regenerated and the TFD is modified whereby the entire track is indicated as being initialized.

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: According to one embodiment, a method includes receiving device information from a source system; building a virtual device on a host system based at least in part on the received device information; at least one of: transferring a reserve of a device stored on a storage device to a target system; and receiving results of transferring the reserve to the target system; determining if the reserve is held by the target system; recording the reserve if the reserve is held by the target system; and sending a notification that the reserve is not held by the target system if the reserve is not held by the target system. Other methods are also described according to various embodiments.

Abstract: According to one embodiment, a host system includes logic adapted for receiving device information from a source system, logic adapted for building a virtual device based at least in part on the received device information, logic adapted for transferring a reserve of a storage device to the host system and/or receiving results of transferring the reserve to the host system, logic adapted for determining if the reserve is held by the host system, logic adapted for recording the reserve if the reserve is held by the host system, and logic adapted for sending a notification that the reserve is not held by the host system if the reserve is not held by the host system. Other methods, systems, and computer program products are also described according to various embodiments.

Abstract: An apparatus, system, and method are disclosed for device level enablement of a communications protocol. An adapter compatibility module determines an adapter compatibility status for a plurality of host adapters. A positive adapter compatibility status indicates that each host adapter in the plurality of host adapters is compatible with a communications protocol. A processor compatibility module determines a processor compatibility status for one or more processors. The one or more processors coordinate data transfers to and from the plurality of host adapters. A positive processor compatibility status indicates that each of the one or more processors is compatible with the communications protocol. A compatibility summary module determines a compatibility summary for the plurality of host adapters and the one or more processors.

Abstract: Deleting a data volume from a storage system and freeing its storage space to make it available to be allocated to a new volume is accomplished by only zeroing associated metadata for the tracks contained in the freed storage space which is then reused in a new volume allocation and an attempt is made by the new volume to read a first record R0 of a track. A determination is made as to whether a first user record R1 of the volume is stale If the first record R0 is stale. If record R1 is stale, the metadata or track format description (TFD) is modified whereby the entire track is indicated as being uninitialized and the first record R0 is uninitialized. If record R1 is not stale, the first record R0 is regenerated and the TFD is modified whereby the entire track is indicated as being initialized.

Abstract: Deleting a data volume from a storage system and freeing its storage space to make it available to be allocated to a new volume is accomplished by only zeroing associated metadata for the tracks contained in the freed storage space which is then reused in a new volume allocation and an attempt is made by the new volume to read a first record R0 of a track. A determination is made as to whether a first user record R1 of the volume is stale If the first record R0 is stale. If record R1 is stale, the metadata or track format description (TFD) is modified whereby the entire track is indicated as being uninitialized and the first record R0 is uninitialized. If record R1 is not stale, the first record R0 is regenerated and the TFD is modified whereby the entire track is indicated as being initialized.

Abstract: A computer storage system includes a supervisor algorithm to detect a host computer's initiator logging in. The supervisor algorithm identifies data storage devices associated with the newly logged-on initiator and tags logical unit number control blocks (“LUNCBs”) as having priority in an initiation process. The supervisor algorithm assigns a task control block to each of the identified data storage devices and invokes a logical unit number (“LUN”) initialization algorithm. If the supervisor algorithm was invoked during an initial microcode load (“IML”) event, the LUN initialization algorithm initializes each of the identified data storage devices. However, if the supervisor algorithm was invoked during a warmstart procedure, the LUN initialization algorithm first checks to make sure the LUNCB was not mistakenly written too. If not, the LUN initialization algorithm terminates without initializing the associated data storage device.

Abstract: A method to initialize information disposed in an information storage and retrieval system comprising a data cache and one or more information storage media comprising a plurality of addresses. The method receives an initialization command, where that initialization command comprises a range of addresses and, optionally, an initialization pattern, where the plurality of addresses includes the range of addresses. The method forms and saves state information, where that state information includes the initialization pattern, and generates and saves a plurality of indicators, where that plurality of indicators includes an indicator for each track comprising the range of addresses. The method sets each of those indicators to a first value thereby indicating special handling, and provides an ending status signal, such that the receiving step, forming step, generating step, setting step, and providing step are performed substantially synchronously.