Abstract: An apparatus for providing storage control in a network of storage controllers is disclosed. The apparatus includes an owner storage controller; an I/O performing component, an ownership assignment component, a lock manager and a messaging component. The ownership assignment component assigns ownership of metadata for data to an owner storage controller. The lock manager controls the locking of metadata during I/O. The messaging component passes messages among storage controllers to request metadata state, to grant locks, to request release of locks, and to signal lock release. The I/O is performed on data whose metadata is owned by an owner storage controller, subject to compliance with metadata lock protocols controlled by the owner storage controller, and any copy of the data held from time to time is maintained in a coherency relation with the data.

Abstract: An apparatus configured to operate as a primary for a remote copy pair is provided. The apparatus comprises a journal component at said primary for generating journal entries for one or more uncompleted sequenced batches; a configurator responsive to an error indication from a secondary for enumeration of said one or more uncompleted sequenced batches; and a primary server responsive to said enumeration of said one or more uncompleted sequenced batches to reissue to said secondary one or more write requests for said one or more uncompleted sequenced batches, during recovery processing.

Abstract: A storage network includes a path processor for directing data onto one of two or more paths between an application host and two or more storage controllers in a storage subsystem. To determine a data path within the storage network, the operational status of a storage controller in the storage subsystem is monitored. It is determined whether a change in the operational status of the storage controller is a failure or a potential failure. This determination is sent to the path processor. The path processor redirects application host data from the path controller on the basis of the determination.

Abstract: According to one general embodiment of the present invention, there is provided a computer program product for reducing incidence of errors in connections between a power consumer apparatus operable to draw a load and a power supply apparatus capable of varying the power supplied, the computer program product comprising: a computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising: computer readable program code configured to generate at the power consumer apparatus an identifiable pattern in a load to be drawn from a power supply connection to a power supply apparatus; and computer readable program code configured to monitor at the power consumer apparatus for a change in the load corresponding to the pattern, the monitoring being performed across a signal connection to the power supply apparatus; wherein a positive result of the monitoring indicates a correct configuration. Additional embodiments are also presented.

Abstract: According to a first general aspect of the present invention, there is provided a logic arrangement for reducing incidence of errors in connections between a power consumer apparatus and a power supply apparatus, the logic arrangement comprising: a pattern-generating component for generating an identifiable pattern in a load to be drawn from a power supply connection to a power supply apparatus; and a testing component for monitoring across a signal connection to the power supply apparatus, the testing component monitoring for a change in the load corresponding to the pattern. A positive result of the testing by the testing component indicates a correct configuration. Additional embodiments are also presented.

Abstract: A computer system for fast format or reproducing data of a computer data storage device includes a computer system executing a reproducing process for reproducing data. A source disk (Ds) data storage device and a target disk (Dt) data storage device have data communication between each other and communicate with the computer system. The Ds data is reproducible to the Dt, and the Ds has blank regions with no data which corresponds to zero. The Ds having data regions and an intermediary flash copy map (D0) is generated by the program having all logical zeros for copying blank regions in the Ds to the Dt. The Ds is disengaged from reproducing after all data regions are copied from the Ds to the Dt. The reproducing of the Ds to the Dt continues after disengaging the Ds from the reproducing process by copying the zeros of the D0 to the Dt.

Abstract: An arrangement and method for update of configuration cache data in a disk storage subsystem in which a cache memory (110) is updated using two-phase (220, 250) commit technique. This provides the advantage that known changes to the subsystem do not require an invalidate/rebuild style operation on the cache. This is especially important where a change will invalidate the entire cache.

Abstract: A storage controller (104) for a storage system (100) in which there are multiple storage devices (109) and a method for recording diagnostic information are provided. The storage controller (104) includes a storage device manager (203) which has means for allocating a storage device (109) in the storage system (100) for storing diagnostic data. The storage controller (104) also includes means for generating diagnostic data regarding the operation of the storage controller (104). Two buffers (207, 208) are used for alternately recording and writing batches of diagnostic data to the allocated storage device (109). The allocated storage device may be a storage device which is normally reserved for disaster recovery in the storage system (100).

Abstract: An apparatus for data transmission over a network includes a buffer and a timer mechanism for timing an optimum interval (less than the round-trip error response delay) for retransmission of data. A first accessor accesses data in the buffer for transmission and starts a first timeout clock. Second or further accessors of the buffer are responsive to a timeout to access the data, start a timeout clock and attempt to transmit the data on a path avoiding path elements used by prior accessors. A counter increments and decrements a count of the references to the buffer by accessors and signals when the count reaches zero. A memory manager returns the buffer to a free buffer pool responsive to the reference counter signaling that the count has reached zero. An analysis mechanism can be used to determine the optimum interval and tune the timer mechanism.

Abstract: Write requests from host computers are processed in relation to a thin provisioning storage subsystem. A write request is received from a host computer. The write request identifies a first virtual disk that has been previously assigned to the host computer. It is determined whether the first virtual disk has to be allocated additional physical storage locations of the thin provisioning storage subsystem for storing data associated with the write request. In response to determining that the virtual disk has to be allocated additional physical storage locations, the following is performed. First, a quantity of free space remaining unallocated within physical storage locations of the thin provisioning storage subsystem is determined. Second, where the quantity of free space remaining unallocated within the physical storage locations satisfies a policy threshold associated with a second virtual disk, the second virtual disk is write-inhibited. The first and second virtual disks can be different.

Abstract: A storage controller (104) for a storage system (100) in which there are multiple storage devices (109) and a method for recording diagnostic information are provided. The storage controller (104) includes a storage device manager (203) which has means for allocating a storage device (109) in the storage system (100) for storing diagnostic data. The storage controller (104) also includes means for generating diagnostic data regarding the operation of the storage controller (104). Two buffers (207, 208) are used for alternately recording and writing batches of diagnostic data to the allocated storage device (109). The allocated storage device may be a storage device which is normally reserved for disaster recovery in the storage system (100).

Abstract: A method for managing operations in a data storage system comprising at least a first storage controller operating according to a plurality of operation states set by a managing entity is provided. The method comprises the first storage controller performing a first operation associated with a first operation state, in response to the managing entity updating state information stored in a data structure readable by the first storage controller.

Abstract: Input/output (I/O) I/O target selection is achieved within a data storage system having clustered nodes of initiators, I/O targets, and grouped storage logical units. A state definition component defines access states for each combination of one or more combinations of a node, an I/O target, and a storage logical unit. A profiler component produces an access state profile for each I/O target. A rank criteria compiler compiles rank criteria as a basis for best-fit identification of I/O targets for a logical unit (LU) group. A best-fit identifier is responsive to the profile component and the rank criteria compiler and identifies a ranked best-fit order of I/O targets for an LU group. A target selector selects an I/O target for an LU group from the ranked best-fit order.

Abstract: An arrangement and method for update of configuration cache data in a disk storage subsystem in which a cache memory (110) is updated using two-phase (220, 250) commit technique. This provides the advantage that known changes to the subsystem do not require an invalidate/rebuild style operation on the cache. This is especially important where a change will invalidate the entire cache.

Abstract: An arrangement and method for update of configuration cache data in a disk storage subsystem in which a cache memory (110) is updated using two-phase (220, 250) commit technique. This provides the advantage that known changes to the subsystem do not require an invalidate/rebuild style operation on the cache. This is especially important where a change will invalidate the entire cache.

Abstract: An apparatus and system are provided for isolating a storage application from a network interface driver. The apparatus includes a definition module, an application interface, a translation module, and a data buffer. The definition module defines a set of storage application functions. The translation module translates each storage application function to one or more network interface driver functions. The data buffer transfers data blocks between the storage application and the network interface driver.

Abstract: An apparatus for providing storage control in a network of storage controllers is disclosed. The apparatus includes an owner storage controller; an I/O performing component, an ownership assignment component, a lock manager and a messaging component. The ownership assignment component assigns ownership of metadata for data to an owner storage controller. The lock manager controls the locking of metadata during I/O. The messaging component passes messages among storage controllers to request metadata state, to grant locks, to request release of locks, and to signal lock release. The I/O is performed on data whose metadata is owned by an owner storage controller, subject to compliance with metadata lock protocols controlled by the owner storage controller, and any copy of the data held from time to time is maintained in a coherency relation with the data.

Abstract: An apparatus for providing storage control in a network of storage controllers is disclosed. The apparatus includes an owner storage controller; an I/O performing component, an ownership assignment component, a lock manager and a messaging component. The ownership assignment component assigns ownership of metadata for data to an owner storage controller. The lock manager controls the locking of metadata during I/O. The messaging component passes messages among storage controllers to request metadata state, to grant locks, to request release of locks, and to signal lock release. The I/O is performed on data whose metadata is owned by an owner storage controller, subject to compliance with metadata lock protocols controlled by the owner storage controller, and any copy of the data held from time to time is maintained in a coherency relation with the data.

Abstract: An apparatus, system, and method are provided for isolating a storage application from a network interface driver. The apparatus includes a definition module, an application interface, a translation module, and a data buffer. The definition module defines a set of storage application functions. The translation module translates each storage application function to one or more network interface driver functions. The data buffer transfers data blocks between the storage application and the network interface driver.

Abstract: An apparatus for providing storage control in a network of storage controllers is disclosed. The apparatus includes an owner storage controller; an I/O performing component, an ownership assignment component, a lock manager and a messaging component. The ownership assignment component assigns ownership of metadata for data to an owner storage controller. The lock manager controls the locking of metadata during I/O. The messaging component passes messages among storage controllers to request metadata state, to grant locks, to request release of locks, and to signal lock release. The I/O is performed on data whose metadata is owned by an owner storage controller, subject to compliance with metadata lock protocols controlled by the owner storage controller, and any copy of the data held from time to time is maintained in a coherency relation with the data.