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 systems and computer program products are also described according to various embodiments.

Abstract: A computer-implemented method for transferring a reserve to a target host, according to one embodiment, includes granting to a source system, by a control unit, a reserve for a volume of a storage device. A push reserve command is received from the source system. The push reserve command specifies: a transfer of the reserve to a target system, parameter data identifying the target system, and path information specifying the source system. The reserve is transferred only to the target system in response to release of the reserve by the source system.

Abstract: Provided are a computer program product, system, and method for processing a health condition message on a health condition to determine whether to perform a swap operation. A health condition message is received from a first server indicating an estimated Input/Output (I/O) delay to access a first storage resulting from a health condition experienced at the first server. A determination is made as to whether the estimated I/O delay exceeds a threshold response time for the first storage. A swap operation is performed to redirect I/O requests to data from the first server to the second server to access the data at the second storage in response to determining that the estimated I/O delay exceeds the threshold response time.

Abstract: Provided are a computer program product, system, and method for generating a health condition message on a health condition detected at a first server to send to a host system accessing the first server. A determination is made of a health condition with respect to access to a first storage. A determination is made of an estimated Input/Output (I/O) delay to access the first storage resulting from the determined health condition. A health condition message is generated indicating the estimated I/O delay. The health condition message is transmitted to the host system, wherein the host system uses the estimated I/O delay to determine whether to perform a swap operation to redirect host I/O requests to data from the first server to a second server.

Abstract: Provided are a computer program product, system, and method for a computer program product, system, and method for determining an availability score based on available resources of different resource types in a distributed computing environment of storage servers to determine whether to perform a failure operation for one of the storage servers. A health status monitor program deployed in the storage servers performs: maintaining information indicating availability of a plurality of storage server resources for a plurality of resource types; calculating an availability score as a function of a number of available resources of the resource types; and transmitting information on the availability score to a management program. The management program uses the transmitted information to determine whether to migrate services from the storage server from which the availability score is received to at least one of the other storage servers in the distributed computing environment.

Abstract: A method for preventing data loss in a RAID includes monitoring storage drives making up a RAID. The method individually tests a storage drive of the RAID by subjecting the storage drive to a stress workload test. This stress workload test may be designed to place additional stress on the storage drive while refraining from adding stress to other storage drives in the RAID. In the event the storage drive fails the stress workload test (e.g., the storage drive cannot adequately handle the additional workload or generates errors in response to the additional workload), the method replaces the storage drive with a spare storage drive and rebuilds the RAID. In certain embodiments, the method tests the storage drive with greater frequency as the age of the storage drive increases. A corresponding system and computer program product are also disclosed.

Abstract: Provided are a computer program product, system, and method for a computer program product, system, and method for determining an availability score based on available resources of different resource types in a distributed computing environment of storage servers to determine whether to perform a failure operation for one of the storage servers. A health status monitor program deployed in the storage servers performs: maintaining information indicating availability of a plurality of storage server resources for a plurality of resource types; calculating an availability score as a function of a number of available resources of the resource types; and transmitting information on the availability score to a management program. The management program uses the transmitted information to determine whether to migrate services from the storage server from which the availability score is received to at least one of the other storage servers in the distributed computing environment.

Abstract: A plurality of cores are maintained in a processor complex. A core of the plurality of cores is reserved for execution of critical tasks, wherein it is preferable to prioritize execution of critical tasks over non-critical tasks. A scheduler receives a task for scheduling in the plurality of cores. In response to determining that the task is a critical task, the task is scheduled for execution in the reserved core.

Abstract: A plurality of processing entities are maintained in a processor complex. In response to determining that a task is a critical task, the critical task is dispatched to a scheduler, wherein it is preferable to prioritize execution of critical tasks over non-critical tasks. In response to dispatching the critical task to the scheduler, the scheduler determines which processing entity of the plurality of processing entities has a least amount of processing remaining to be performed for currently scheduled tasks. Tasks queued on the determined processing entity are moved to other processing entities, and the currently scheduled tasks on the determined processing entity are completed. In response to moving tasks queued on the determined processing entity to other processing entities and completing the currently scheduled tasks on the determined processing entity, the critical task is dispatched on the determined processing entity.

Abstract: A method for intelligently rebuilding a RAID includes subjecting a storage drive in an existing RAID to a stress workload test by placing the storage drive in a RAID 1 configuration with a spare storage drive. In the event the storage drive fails the stress workload test but can still be read, the method uses the RAID 1 configuration to copy recoverable data from the failing storage drive to the spare storage drive. The method uses other storage drives in the existing RAID to reconstruct, on the spare storage drive, data that is not recoverable from the failing storage drive. Either before or after all non-recoverable data has been reconstructed on the spare storage drive, the method logically replaces, in the existing RAID, the failing storage drive with the spare storage drive. A corresponding system and computer program product are also disclosed.

Abstract: A method for preventing data loss in a RAID includes monitoring the age of storage drives making up a RAID. When a storage drive in the RAID reaches a specified age, the method individually tests the storage drive by subjecting the storage drive to a stress workload test. This stress workload test may be designed to place additional stress on the storage drive while refraining from adding stress to other storage drives in the RAID. In the event the storage drive fails the stress workload test (e.g., the storage drive cannot adequately handle the additional workload or generates errors in response to the additional workload), the method replaces the storage drive with a spare storage drive and rebuilds the RAID. In certain embodiments, the method tests the storage drive with greater frequency as the age of the storage drive increases. A corresponding system and computer program product are also disclosed.

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: Provided are a computer program product, system, and method for sharing alias addresses among logical devices for a control unit managing access by hosts to logical devices configured with capacity from attached physical devices. An alias management group of logical devices and alias addresses assigned to the logical devices is configured. A plurality of requests to establish an association of the host with a logical device and the alias addresses assigned to the logical devices in the alias management group are received from a host. Acknowledgment is made to the host that the association is established in response to determining that the host is assigned the logical devices and alias addresses of the logical devices in the alias management group. The host can use one available alias address assigned to any one of the logical devices to access any one of the logical devices indicated in the association.

Abstract: Provided are a computer program product, system, and method for sharing alias addresses among logical devices by a host accessing logical devices provisioned with a capacity from physical devices managed by a control unit. The host establishes with the control unit an association of logical devices and alias addresses assigned to the logical devices, wherein the alias addresses are associated with an alias management group. Alias address pool information is generated indicating each of the logical devices and their assigned alias addresses indicated in the association. The host uses from the alias address pool information any one of the alias addresses in the alias address pool information to access any of the logical devices associated with the same alias management group as the alias address.

Abstract: Provided are a computer program product, system, and method for determining an availability score based on available resources of different resource types in a storage system to determine whether to perform a failure operation for the storage system. Information is maintained indicating availability of a plurality of storage system resources for a plurality of resource types. An availability score is calculated as a function of a number of available resources of the resource types. Information on the availability score is transmitted to a failure manager. The failure manager uses the transmitted availability information to determine whether to initiate a storage system failure mode for the storage system.

Abstract: A method for intelligently rebuilding a RAID includes subjecting a storage drive in an existing RAID to a stress workload test by placing the storage drive in a RAID 1 configuration with a spare storage drive. In the event the storage drive fails the stress workload test but can still be read, the method uses the RAID 1 configuration to copy recoverable data from the failing storage drive to the spare storage drive. The method uses other storage drives in the existing RAID to reconstruct, on the spare storage drive, data that is not recoverable from the failing storage drive. Either before or after all non-recoverable data has been reconstructed on the spare storage drive, the method logically replaces, in the existing RAID, the failing storage drive with the spare storage drive. A corresponding system and computer program product are also disclosed.

Abstract: A method for preventing data loss in a RAID includes monitoring the age of storage drives making up a RAID. When a storage drive in the RAID reaches a specified age, the method individually tests the storage drive by subjecting the storage drive to a stress workload test. This stress workload test may be designed to place additional stress on the storage drive while refraining from adding stress to other storage drives in the RAID. In the event the storage drive fails the stress workload test (e.g., the storage drive cannot adequately handle the additional workload or generates errors in response to the additional workload), the method replaces the storage drive with a spare storage drive and rebuilds the RAID. In certain embodiments, the method tests the storage drive with greater frequency as the age of the storage drive increases. A corresponding system and computer program product are also disclosed.

Abstract: Various embodiments managing host recovery operations in a computing storage environment, by a processor device, are provided. Real-time indications are provided from a device to each of at least one of a plurality of hosts that a connected storage controller is entering a recovery operation, and real-time sense data is provided to the at least one of the plurality of hosts for presenting an indication of an expected recovery timeframe.

Abstract: Embodiments of the present disclosure may relate to methods and a computer program product for allowing writes based on a granularity level. The method for a storage server may include receiving a received granularity level for a particular volume of a storage device of a client computer including an effective duration for the received granularity level. The method may include receiving an anticipated write to the particular volume at an anticipated write granularity level. The method may include verifying whether the anticipated write granularity level substantially matches the received granularity level at the effective duration. The method may also include writing, in response to the anticipated write granularity level substantially matching the received granularity level at the effective duration, the anticipated write to the particular volume for the received granularity level.

Abstract: Embodiments of the present disclosure may relate to methods and a computer program product for allowing writes based on a granularity level. The method for a storage server may include receiving a received granularity level for a particular volume of a storage device of a client computer including an effective duration for the received granularity level. The method may include receiving an anticipated write to the particular volume at an anticipated write granularity level. The method may include verifying whether the anticipated write granularity level substantially matches the received granularity level at the effective duration. The method may also include writing, in response to the anticipated write granularity level substantially matching the received granularity level at the effective duration, the anticipated write to the particular volume for the received granularity level.