Abstract: A mechanism is provided for managing operations in a data storage system. A first storage controller monitors operation state information associated with a plurality of operation states stored in a data structure. The first storage controller detects a change in the operation state information. The change in the operation state information is in response to a managing entity updating the operation state information to a first operation state in the plurality of operation states in the data structure. Responsive to detecting the change in the operation state information, the first storage controller identifies a reference to a first operation associated with the first operation state updated by the managing entity. The first operation is one operation in a plurality of operations. The first storage controller performs the first operation associated with the first operation state.

Abstract: A system, backup components and computer program product are provided to improve the efficiency of the transmission of consistency groups across multiple storage components by ensuring that volume transactions are evenly allocated among backup components. Each volume is initially assigned to a specified backup component. Once a color period begins, volume transactions are transmitted to the assigned backup component. Each backup component accumulates data transfer information for its assigned volumes throughout at least a portion of the color period and calculates a new volume assignment for the next color period. Before the start of the next color period, a captain storage controller transmits any new assignments to the backup components. During a next color period, the process is repeated using the new assignments.

Abstract: An apparatus, system, and method are disclosed for executing functions in an event driven environment. A bridge module stores parameters and a proxy function pointer for a proxy function in a bridge structure for a co-routine context executing in a co-routine environment. The proxy function is configured to execute in an event driven environment. The bridge module also stores a bridge pointer for the bridge structure in a bridge pointer register of an event driven context structure. A swap context module swaps to the event driven context. An execute module retrieves the proxy function pointer from the bridge structure using the bridge pointer if the bridge pointer register is not null, executes the proxy function, and stores the results of the proxy function in the bridge structure.

Abstract: A non-disruptive method for updating firmware in a first controller 210 of a redundant controller 200 in a storage subsystem 120 is disclosed. This updating occurs while the storage subsystem 120 presents data to a host system 130 in response to a host request 132. During the non-disruptive updating, the updating first controller 210 redirects the host request 132 for data, e.g., drive-A volume 252 normally owned by the first controller 210, to second controller 220 of the redundant controller 200. After the second controller 220 obtains data 134 identified in the host request 132, the operating second controller 220 transfers the data 134 to the updating first controller 210 via an inter-controller channel 202. Once the updating first controller 210 receives the data 134, the first controller 210 presents the data 134 to the host system 130. The host system 130 does not detect that the first controller 210 is updating because the updating process is invisible to the host system 130.

Abstract: An apparatus, system, and method are disclosed for switching a volume address association in a point-in-time copy relationship. A copy module creates a point-in-time copy structure of a source volume at a target volume. A migration module copies data from the source volume to the target volume. A detection module detects data corruption in the source volume. A switch module switches a logical volume address from a source volume address of the source volume to a target volume address of the target volume in response to detecting the data corruption, redirecting data reads and writes to the target volume. In one embodiment, a tracking module tracks a current target volume copy of source volume data and redirects an access for source volume data without the current target volume copy to the source volume.

Abstract: An apparatus and method to replicate one or more files between non-symmetric storage systems are disclosed. The method supplies a first storage system comprising a first configuration, a first volume, a first file system, and a first replication appliance comprising first replication appliance memory. The method further supplies a second storage system comprising a second configuration, a second volume, a second file system, and a second replication appliance comprising second replication appliance memory, where the first configuration differs from the second configuration. The first storage system receives a dataset, writes that dataset to the first volume as a first file. Applicants' method then replicates the first file to the second volume as a second file, and maintains in the second replication appliance memory a second replication appliance mapping associating the first file with the second file.

Abstract: An apparatus, system, and method are disclosed for a read-before-write storage controller instruction. A sequencer receives an atomic read-before-write instruction comprising new data, a target address for the new data, and an undo log address. An I/O unit reads old data from the target address, writes the old data and the target address to the undo log address, and writes the new data to the target address as directed by the sequencer.

Abstract: An apparatus for controlling a storage system having a data replication function, comprises: a storage array component being operable to send notification to a replication engine that a write of data to a primary storage location by a host is subject to data replication; the replication engine being operable to receive the notification and in response to instruct the storage array to copy the data to a secondary storage location; wherein the data is copied to the secondary storage location unmediated by the replication engine.

Abstract: A method to optimize the transmission of data from (N) primary backup appliances interconnected to a plurality of second backup appliances by a single communication link, wherein (N) is greater than 1, by transferring a data set to one or more secondary backup appliances by two or more of the (N) primary backup appliances using the communication link, and completing those transfers of the data sets by the two or more primary backup appliances at the same time.

Abstract: In a data processing environment, data is replicated to a remote or secondary storage device in a manner which reduces the adverse performance effects and inefficient bandwidth usage imposed by the conventional one-transaction-at-a-time process. Transactions to be transferred are grouped by a replication manager by selecting transactions having start times earlier than the completion time of a first transaction. Thus, no transaction in a group will be dependent upon any other transaction in the group. Once selected, all transactions in the group may then be transferred to the secondary storage device.

Abstract: A method to select a captain control node from a plurality of interconnected control nodes is disclosed. The method provides by each of the plurality of control nodes a first signal to each of the other control nodes, and then receives by each of the plurality of control nodes, a response signal from each of the other control nodes. The method then calculates by each of the plurality of control nodes individual response times for each of the other control nodes, and determines by each control node its aggregate response time. The method then determines whether to select a captain control node using the aggregate response times. If the captain control node is selected using the aggregate response times, then the method then determines the minimum aggregate response time, and designates the control node having that minimum aggregate response time the captain control node.

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: A method is provided to improve the efficiency of the transmission of consistency groups across multiple storage components by ensuring that volume transactions are evenly allocated among backup components. Each volume is initially assigned to a specified backup component. Once a color period begins, volume transactions are transmitted to the assigned backup component. Each backup component accumulates data transfer information for its assigned volumes throughout at least a portion of the color period and calculates a new volume assignment for the next color period. Before the start of the next color period, a captain storage controller transmits any new assignments to the backup components. During a next color period, the process is repeated using the new assignments.

Abstract: An apparatus, system, and method are disclosed for executing functions in an event driven environment. A bridge module stores parameters and a proxy function pointer for a proxy function in a bridge structure for a co-routine context executing in a co-routine environment. The proxy function is configured to execute in an event driven environment. The bridge module also stores a bridge pointer for the bridge structure in a bridge pointer register of an event driven context structure. A swap context module swaps to the event driven context. An execute module retrieves the proxy function pointer from the bridge structure using the bridge pointer if the bridge pointer register is not null, executes the proxy function, and stores the results of the proxy function in the bridge structure.

Abstract: A system, method and computer program product are provided to improve the efficiency of the transmission of consistency groups across multiple storage components by ensuring that volume transactions are evenly allocated among backup components. Each volume is initially assigned to a specified backup component. Once a color period begins, volume transactions are transmitted to the assigned backup component. Each backup component accumulates data transfer information for its assigned volumes throughout at least a portion of the color period and calculates a new volume assignment for the next color period. Before the start of the next color period, a captain storage controller transmits any new assignments to the backup components. During a next color period, the process is repeated using the new assignments.

Abstract: A method to adjust the data transfer rate for one of (N) primary backup appliances. The method forms by a first primary backup appliance at least one consistent transactions set. The first primary backup appliance receives the (n)th status signal, and the (n+1)th status signal from each of the other (N?1) primary backup appliances. The method calculates the (n)th effective bandwidth for each of the (N) primary backup appliances, the (n)th time to complete for each of the (N) primary backup appliances, and the (n)th effective aggregate bandwidth for all (N) primary appliances. If the (n)th time to complete for the first primary backup appliance is greater than the (n)th time to complete for each of the other (N?1) primary backup appliances, then the method provides at least one consistent transactions set from the first primary backup appliance to a first secondary backup appliance with no delay.

Abstract: A method, apparatus, and article of manufacture containing instructions for processing multiple point-in-time consistent data sets. The method consists of creating multiple point-in-time data sets associated with a backup appliance which is associated with backup storage. Upon the transfer of a first update from a primary storage controller to the backup appliance, a determination is made whether the update affects data stored in the backup storage has been unchanged following the creation of the respective data sets. If the update does affect data which is unchanged following the creation of a data set, the current, non-updated data is read from the backup storage. A copy of the current, non-updated data thus read from the backup storage is stored in a storage location which can be one of the data sets or an independent memory location. In addition, pointers are associated with the remaining applicable data sets and directed to the copy at its storage location.

Abstract: A method to adjust the data transfer rate for one of (N) primary backup appliances. The method forms by a first primary backup appliance at least one consistent transactions set. The first primary backup appliance receives the (n)th status signal, and the (n+1)th status signal from each of the other (N?1) primary backup appliances. The method calculates the (n)th effective bandwidth for each of the (N) primary backup appliances, the (n)th time to complete for each of the (N) primary backup appliances, and the (n)th effective aggregate bandwidth for all (N) primary appliances. If the (n)th time to complete for the first primary backup appliance is greater than the (n)th time to complete for each of the other (N?1) primary backup appliances, then the method provides at least one consistent transactions set from the first primary backup appliance to a first secondary backup appliance with no delay.

Abstract: Emulation of a small computer system interface (SCSI) library storage is provided in a virtual data storage subsystem having an automated tape library. This allows the ability to access or store a logical volume of data. Medium changer commands as used in SCSI and other open system interfaces are mapped to library function commands as commonly used in an enterprise server environment. This allows full transparent usage of virtual tape storage available in the enterprise server environment as open system storage.

Abstract: A method for managing Data Storage Medium (DSM) mount and demount decisions in an automated data storage library that dynamically optimizes both sequential and random data access workloads. The demount decisions adapt to time-varying characteristics in the relative workload mix. When the workload is primarily sequential, the mount and demount decision procedure favors longer mount residency for sequential access streams, reducing the robotic picker activity and reducing response time for mount requests. When the workload is predominantly random access, sequentially accessed DSM residency time is generally reduced and preemptive demounts are more readily implemented. The disclosed method provides for preemptive demounts and uses a two-element decision process to select either a Least Recently Used (LRU) or a Least Recently Mounted (LRM) decision parameter. The relative weights of the LRU and LRM decision tests are varied responsive to measured changes in data access workload characteristics.