Abstract: A method of extending functionality of a data storage facility by adding to the primary storage system new functions using extension function subsystems is disclosed. One example of extending the functionality includes compressing and caching data in a data storage facility to improve storage and access performance of the data storage facility. A primary storage system queries a data storage extension system for availability of data tracks. If the primary storage system does not receive a response or the data tracks from the data storage extension system, it continues caching by fetching data tracks from a disk storage system. The storage extension system manages compression/decompression of data tracks in response to messages from the primary storage system. Data tracks transferred from the data storage extension system to the primary storage system are marked as stale at the data storage extension system and are made available for deletion.

Abstract: Provided are a method, system, and article of manufacture for authenticating a processing system accessing a resource. An association of processing system identifiers with resources, including a first and second resources, is maintained. A request from a requesting processing system in a host is received for use of a first resource that provides access to a second resource, wherein the request is generated by processing system software and wherein the request further includes a submitted processing system identifier included in the request by host hardware in the host. A determination is made as to whether the submitted processing system identifier is one of the processing system identifiers associated with the first and second resources. The requesting processing system is provided access to the first resource that the processing system uses to access the second resource.

Abstract: Provided are a method, system, and article of manufacture, wherein a command is received at a first computational device coupled to a first adapter that is capable of allowing access to a data storage to the first computational device. The first computational device sends the command to a second computational device. The command is processed by a second adapter coupled to the second computational device, wherein the second adapter allows the second computational device to access the data storage, and wherein the second adapter accesses memory in the first computational device to process the command. In certain embodiments, the first adapter that allows the first computational device to access the data storage has failed.

Abstract: A system is provided to protect against ill-behaved microcode by balancing between an actual occurrence of a hardware problem and a microcode bug setting a flag appearing as a hardware problem. In this method, the error recovery is performed only on a single piece of hardware and no further error recovery action is taken on other pieces of similar hardware. The approach addresses the problem by treating a hit on one card as a hardware problem, but as a bug on subsequent cards. The invention keeps track of whether or not the same event has occurred on the same type of hardware so not to take action on more than one instance of the hardware. Subsequent hits on another instance of the hardware will not trigger the hardware related recovery on additional hardware.

Abstract: A first device determines a possibility of an invalidation of a second device, wherein the first device is coupled to the second device via a fabric. A query is sent from the first device to validate the second device, in response to determining the possibility of the invalidation of the second device. A determination is made, at the first device, whether to continue I/O operations from the first device to the second device based on receiving a response to the query within a time period.

Abstract: A method, apparatus, and computer instructions for controlling data flow. A control message is formed for the data flow in response to an event while the data flow is occurring. The control message includes a data type, an action, and a duration. The control message is sent to a receiver data processing system, wherein the receiver data processing system modifies the data flow to the data processing system using the control message.

Abstract: Provided are a method, system, and article of manufacture for determining whether to use a full volume or repository for a logical copy backup space. A determination is made of a source volume to backup using a logical copy operation. The logical copy operation is completed upon indicating the source volume data to backup. During a logical copy duration, point-in-time data in the source volume as of a point-in-time when the logical copy was established is copied to a backup space in response to receiving an update to the point-in-time data. A history of writes to the source volume is processed to determine whether to allocate a full target volume as the backup space providing a corresponding data unit for each data unit in the source volume or allocate a repository as the backup space, wherein the repository uses less storage space than the full target volume. The logical copy operation using the determined full target volume or repository as the backup space is initiated.

Abstract: Provided are a method, system, and article of manufacture for determining whether to use a repository to store data updated during a resynchronization. Writes to a primary storage are transferred to a secondary storage. A logical copy of the secondary storage as of a point-in-time is established. Writes to the secondary storage in the logical copy received from the primary storage during a logical copy duration after the point-in-time are stored in a repository that comprises less storage space than the secondary storage in the logical copy. The transferring of writes to the secondary storage is suspended. During the suspension writes to the primary storage are indicated in an out-of-synch data structure.

Abstract: Provided are a method, system, and article of manufacture, wherein a primary storage control unit receives an information unit from a remote host over a fibre channel connection, wherein persistent information unit pacing is implemented over the fibre channel connection. Information is maintained on how many large writes have been received at the primary storage control unit over at least one logical path established over the fibre channel connection between the primary storage control unit and the remote host, wherein a large write is an input/output (I/O) operation for which a number of data information units that are processed exceeds a default value of an information unit pacing credit.

Abstract: Provided are a system and article of manufacture for providing an address format compatible with different addressing formats used for addressing different sized address spaces. An address format is used in an operating system to address storage space in a storage device comprising a first region and a second region of storage space. A first group of applications uses the address format to only address the storage space in the first region and is not coded to use the address format to access the second region and a second group of applications uses the address format to address the storage space in the first and second regions.

Abstract: An apparatus, system, and method are disclosed for communicating binary data using a self-descriptive binary data structure. The binary data structure also may be referred to as a microcode reconstruct and boot (MRB) image. The binary data structure includes a plurality of data segments, a target data set, and a data structure descriptor. Each of the data segments has a data segment header and data field. The target data set is stored within the data field and may be an executable. The data structure descriptor is descriptive of the binary data structure and identifies the location of the target data set within the data field. The binary data structure is self-descriptive in that the location of an individual target data set may be identified by the data structure descriptor.

Abstract: Provided are a system and an article of manufacture, wherein a primary storage control unit receives an information unit from a remote host over a fibre channel connection. The primary storage control unit adjusts an information unit pacing parameter included in a response sent from the primary storage control unit to the remote host, wherein the information unit pacing parameter indicates the number of information units that the remote host is allowed to send to the primary storage control unit without waiting for any additional response from the primary storage control unit.

Abstract: Provided is a method, system, and article of manufacture for providing an address format compatible with different addressing formats used for addressing different sized address spaces. An address format is used in an operating system to address storage space in a storage device comprising a first region and a second region of storage space. A first group of applications uses the address format to only address the storage space in the first region and is not coded to use the address format to access the second region and a second group of applications uses the address format to address the storage space in the first and second regions.

Abstract: A plurality of storage devices of a plurality of types is provided. A plurality of criteria is associated for each of the plurality of storage devices, based on characteristics of the plurality of storage devices, wherein the plurality of criteria can be used to determine whether a selected storage device is a compatibility spare for a storage device in a storage device array, and whether the selected storage device is an availability spare for the storage device in the storage device array. A determination is made by a spare management application, based on at least the plurality of criteria and at least one optimality condition, of a first set of storage devices selected from the plurality of storage devices to be allocated to a plurality of storage device arrays, and of a second set of storage devices selected from the plurality of storage devices to be allocated as spares for the plurality of storage device arrays.

Abstract: A primary storage control unit receives an information unit from a remote host over a fibre channel connection. The primary storage control unit adjusts an information unit pacing parameter included in a response sent from the primary storage control unit to the remote host, wherein the information unit pacing parameter indicates the number of information units that the remote host is allowed to send to the primary storage control unit without waiting for any additional response from the primary storage control unit.

Abstract: A method is provided to protect against ill-behaved microcode by balancing between an actual occurrence of a hardware problem and a microcode bug setting a flag appearing as a hardware problem. In this method, the error recovery is performed only on a single piece of hardware and no further error recovery action is taken on other pieces of similar hardware. The approach addresses the problem by treating a hit on one card as a hardware problem, but as a bug on subsequent cards. The invention keeps track of whether or not the same event has occurred on the same type of hardware so not to take action on more than one instance of the hardware. Subsequent hits on another instance of the hardware will not trigger the hardware related recovery on additional hardware.

Abstract: Provided are a method, system, and program for reassigning storage volumes from a failed processing system to a surviving processing system. A first processing system detects a failure of a second processing system. The first processing system determines device groups of storage devices managed by the failed second processing system and determines for each determined device group, hosts that connect to storage devices in the device group. The first processing system sends, for each device group, a unit check to each determined host indicating failure of each device group through one storage device in the device group to which the determined host connects. The determined hosts execute instructions to terminate any I/O operations in progress on the storage devices in the device group in response to the unit check indicating failure of one storage device in the device group and issue, a command to one storage device for the device group to end the busy condition.

Abstract: Provided are a method, system, and program for reassigning storage volumes from a failed processing system to a surviving processing system. A first processing system detects a failure of a second processing system. The first processing system determines device groups of storage devices managed by the failed second processing system and determines for each determined device group, hosts that connect to storage devices in the device group. The first processing system sends, for each device group, a unit check to each determined host indicating failure of each device group through one storage device in the device group to which the determined host connects. The determined hosts execute instructions to terminate any I/O operations in progress on the storage devices in the device group in response to the unit check indicating failure of one storage device in the device group and issue, a command to one storage device for the device group to end the busy condition.

Abstract: Provided are a method, system, and article of manufacture, wherein a determination is made that a first data array in a plurality of data arrays has to be repaired to replace a failed storage device within the first data array. A storage device is selected from a selected data array of the plurality of data arrays to replace the failed storage device, wherein a data value corresponding to the selected data array is less than the data value corresponding to the first data array.

Abstract: Provided are a method, system, and article of manufacture, wherein a primary storage control unit receives an information unit from a remote host over a fibre channel connection. The primary storage control unit adjusts an information unit pacing parameter included in a response sent from the primary storage control unit to the remote host, wherein the information unit pacing parameter indicates the number of information units that the remote host is allowed to send to the primary storage control unit without waiting for any additional response from the primary storage control unit.