Abstract: Provided are a method, system and article of manufacture for verifying a record as part of an operation to modify the record. A search request is received to determine whether a record matches a value. A first component executes the search request to determine if the record matches the value. The first component sends a verify request to a second component that did not execute the search request to execute the search request to determine whether the record matches the value. A result of the first and second components executing the search request is logged.

Abstract: Provided are a method, system, and article of manufacture for relocating a logical volume from a first storage location to a second storage location using a copy relationship. An operation is initiated to move a logical volume from a first storage location to a second storage location. A relationship is established between the first and second storage locations to copy data in the logical volume from the first storage location to the second storage location. A read request is received to data in the logical volume while copying the data in the logical volume from the first storage location to the second storage location. A determination is made, in response to the read request, whether the requested data is at a first copy of the logical volume in the first storage location or a second copy of the logical volume as the second storage location.

Abstract: An apparatus, system, and method are disclosed for preventing write starvation in a storage controller with access to low performance storage devices. A storage device allocation module is included to assign a storage device write cache limit for each storage device accessible to a storage controller. The storage device write cache limit comprises a maximum amount of write cache of the storage controller available to a storage device for a write operation. At least one storage device comprises a low performance storage device and a total amount of storage available to the storage devices comprises an amount greater than a total storage capacity of the write cache. A low performance write cache limit module is included to set a low performance write cache limit. The low performance write cache limit comprises an amount of write cache available for use by the at least one low performance storage device for a write operation.

Abstract: Provided are a method, system, and article of manufacture for updating metadata in a logical volume associated with a storage controller. A data structure is generated indicating data units in a volume whose metadata is to be updated. An operation is initiated to update the metadata for data units indicated in the data structure. Indication is made in the data structure that the metadata for one data unit has been updated in response to updating the metadata for the data unit. An Input/Output (I/O) request is received to one data unit in the volume while the metadata for the data units indicated in the data structure is being updated. A determination is made, in response to the I/O request, from the data structure whether the metadata for the requested data unit was updated. The metadata for the requested data unit is updated in response to determining that the metadata for the requested data unit has not been updated. The I/O request is executed against the requested data unit.

Abstract: An apparatus, system, and method are disclosed for fastload code update on a communications adapter. The apparatus includes an image load module, a memory initialization module, and an image overlay module. The image load module is configured to load a copy of a new code image in a memory on the communications adapter. The memory also concurrently stores a copy of an old code image used by the communications adapter. The memory initialization module is configured to invoke the new code image to perform a memory initialization operation. The memory initialization module may perform the memory initialization operation concurrently with ongoing I/O requests possibly accepted, but not necessarily processed, by the old code image. The image overlay module is configured to overlay the old code image with the new code image. The fastload code update minimizes the time that the communications adapter is off-line to overlay the old code image with the new code image and reinitialize the communications adapter.

Abstract: An apparatus, system, and method are disclosed for presenting a storage volume as a virtual volume. An attribute module determines a primary volume physical attribute of a primary volume. A presentation module presents the primary volume physical attribute to a host as a target volume virtual attribute of a target volume. A translation module translates communications between a host and the target volume. In one embodiment, a copy module creates a point-in-time copy of the primary volume on the target volume.

Abstract: Provided are a method, system, and program for initiating and using information used for a host, control unit, and logical device connections receiving a request to create a host port to control unit port connection. In a volume group data structure, a volume group entry is defined having a plurality of pointers for the host port and control unit port pair. At least one device address is added to the volume group that is accessible to the host port and control unit port connection by initializing at least one pointer in the volume group entry to address at least one device data structure. For each of the at least one device addresses, indication is made in the at least one device data structure addressed by the at least one pointer in the volume group entry that the device address is accessible to the host port and control unit port connection.

Abstract: Provided are a method, system, and article of manufacture, wherein a request is received for switching a logical volume from one state to another state, wherein the logical volume is in a mirrored state if data corresponding to the logical volume is mirrored from a first storage to a second storage, and wherein the logical volume is in a non-mirrored state if the data corresponding to the logical volume is not mirrored from the first storage to the second storage. A determination is made as to whether to perform the switching, in response to receiving the request.

Abstract: A method to simultaneously configure a plurality of adapters disposed within a computer system, where that computer system includes one or more external computers, and/or one or more data input devices, and/or one or more data output devices, and/or one or more data storage devices. A computer system which includes a computer useable medium having computer readable program code disposed therein to implement Applicants' method to simultaneously configure a plurality of adapters disposed within said computer system. A computer program product usable with a programmable computer processor having computer readable program code embodied therein for simultaneously configuring a plurality of adapters disposed within a computer system.

Abstract: A data management system has at least one class distinction cue associated with a class of data entities. The class distinction cue comprises data management guidance information and priority information related to the associated class of data entities. For a data entity, at run-time, a data management allocation run-time system references the class distinction cue or cues prior to conducting data management allocation or access, and, based on the priority information as compared to other priority information related to the data storage resources, selectively allocates the data storage resources and provides the operations of the storage system in the data management allocation system for the data entity.

Abstract: Disclosed is a method, system, program, and data structure for a storage controller to map logical blocks to physical storage blocks. The storage controller is in communication with at least one host system that views a logical storage space. The storage controller defines the logical storage space as a sequence of logical chunks, wherein each logical chunk comprises a plurality of logical blocks in the logical storage space. The storage controller further defines a physical storage space as a sequence of physical chunks, wherein each physical chunk comprises a plurality of physical blocks in the physical storage system. The storage controller associates each logical chunk in the sequence of logical chunks defining the logical storage space with one physical chunk in the physical storage system. Further, the contiguous logical chunks are capable of being associated with non-contiguous physical chunks.

Abstract: A data management system has at least one class distinction cue associated with a class of data entities. The class distinction cue comprises data management guidance information and priority information related to the associated class of data entities. For a data entity, at run-time, a data management allocation run-time system references the class distinction cue or cues prior to conducting data management allocation or access, and, based on the priority information as compared to other priority information related to the data storage resources, selectively allocates the data storage resources and provides the operations of the storage system in the data management allocation system for the data entity.

Abstract: Disclosed are a method, apparatus, and computer program product to reduce the detrimental effects of taking resources offline. A resource is taken offline in a storage network by quiescing activity to the resource providing notification that the resource will become unavailable, and taking the resource offline.

Abstract: A method to simultaneously configure a plurality of adapters disposed within a computer system, where that computer system includes one or more external computers, and/or one or more data input devices, and/or one or more data output devices, and/or one or more data storage devices. A computer system which includes a computer useable medium having computer readable program code disposed therein to implement Applicants' method to simultaneously configure a plurality of adapters disposed within said computer system. A computer program product usable with a programmable computer processor having computer readable program code embodied therein for simultaneously configuring a plurality of adapters disposed within a computer system.

Abstract: Disclosed is a bridge system for processing read transactions over a bus in which in a preferred embodiment prefetched data stored in a buffer is not discarded if the address of the requested read does not match the beginning address of the prefetched data. Instead, the bridge system skips to the next address of the prefetched data stored in the buffer and compares that address to the address of the read request to determine if a match exists. If the requested read address does match the next prefetched data address, the prefetched data starting at that next address is read out and forwarded to the requesting agent. Alternatively, if there is not a match, the bridge skips again to the next address and continues checking for a match until either the prefetched data is exhausted or another predetermined limit has been reached. In this manner, many unnecessary data reads of data already prefetched in the buffer may be avoided.

Abstract: A data processing system provides a method and apparatus for managing a shared resource between multiple processors. The data processing system includes a first processor for producing, or supplying, available sections of the shared resource, and a second processor for consuming, or allocating, the available sections within the system. The first and second processor share a memory containing a circular queue, a resource queue, for referencing available shared resource sections. The resource queue is initialized by storing a pointer to an available shared resource section in each entry of the resource queue. The second processor consumes an available section of shared resource by removing a resource pointer from a resource queue entry and sending a message signal to a mailbox message subsystem of the first processor.

Abstract: Disclosed is a storage controller for interfacing between a plurality of host systems and direct access storage devices (DASDs). The storage controller includes a bridge, a first host adaptor, and a first device adaptor that are configured to communicate with a first processor. A first DASD is linked to the first device adaptor. The bridge interfaces the first processor, the first host adaptor, and the first device adaptor. The storage controller further includes a second host adaptor and a second device adaptor that are configured to communicate with a second processor. A second DASD is linked to the second device adaptor. The bridge further interfaces the second processor, the second host adaptor, and the second device adaptor. After configuration, an input/output (I/O) request from at least one of the host systems is directed to the first DASD via the first host adaptor, the first processor, and the first device adaptor.

Abstract: A mailbox message system is coupled between a processor having a mailbox and one or more peripheral devices or circuits communicating information to the processor. The mailbox message system in the present invention reports events which occur in the peripheral devices or circuits to the mailbox within the processor to be serviced by the processor. The mailbox message system receives inputs from the processor indicating which events are allowed to be currently serviced by the processor and stores these inputs in a first memory. The mailbox message system further receives unique signals representing distinct events from the peripheral devices and stores these signals in a second memory. The generated events which are pending service in the second memory are then compared with the allowed events in the first memory. When a match exists, a message is encoded and transmitted to the mailbox of the processor indicating that the processor has an event to be serviced.