Abstract: An apparatus, system, and method are disclosed for concurrently relocating a RAID array. The apparatus includes an identification module, a designation module, and an implementation module. The identification module identifies an availability of a physical device within a donor arrayed storage device to offload a source drive of a relocation enclosure. The designation module designates an available physical device as a target drive and thereby designate the target drive and the source drive as a linked pair;. The implementation module implements a mirroring relationship between the target drive and the source drive. The apparatus, system, and method provide a dynamic relocation of the raid array, minimizing system downtime and maximizing efficient utilization of system resources.

Abstract: Provided are a method, system, and article of manufacture, wherein a plurality of processing nodes in a storage system are partitioned into a plurality of logical processing units, and wherein the plurality of logical processing units can respond to I/O requests from a host coupled to the storage system. At least two logical processing units are grouped, wherein data in a first storage coupled to a first logical processing unit of the least two logical processing units is mirrored by data in a second storage coupled to the second logical processing unit of the at least two logical processing units. In response to a failure of the first logical processing unit, an I/O request from the host is responded to via the second logical processing unit.

Abstract: Provided are a method, system, and article of manufacture for assigning alias addresses to base addresses. An assignment is provided of base addresses to the devices, wherein the base addresses are used to access the devices assigned to the base addresses. An assignment is provided of a plurality of alias addresses to an alias address pool. The alias addresses in the alias address pool are capable of being dynamically assigned to the devices to service I/O requests to the devices. An Input/Output (I/O) request to access one target device comprising one of the devices is processed. A determination is made as to whether the base address assigned to the target device is available. One alias address is assigned to the target device in response to determining that the base address is not available. The I/O request is issued to the assigned alias address to transmit the request to the target device.

Abstract: A log-in resource release system includes a set of lists for managing log-in requests to a processing cluster input/output port from host server input/output ports. Host servers that have been granted memory structures within a memory storage device (“configured hosts”) are granted priority access to a storage processing device's input/output port (“cluster port”). If the cluster port has exhausted its log-in resources, log-on requests from non-configured hosts will be not be accepted. New log-in requests from configured hosts will cause a host connected at a link or transport layer but not an upper layer to be logged off. If no hosts are connected only at the link or transport layer, a non-configured host connected at an upper layer will be logged off. If only configured hosts are connected and only at the upper layer, the log-on request by the configured host will be denied.

Abstract: A method to control access to logical volumes disposed in an information storage and retrieval system using parallel access volumes. The method provides an information storage and retrieval system comprising a plurality of logical volumes, and a plurality of host computers, where each host computers is capable of communicating with the information storage and retrieval system. The method creates a parallel access volume having an alias, and persistently associates that parallel access volume with an original base logical volume, where the original base logical volume may be assigned to one of (N) logical volume groups. If the original base logical volume is assigned to the (i)th logical volume group, the method permits each host computers assigned to the (i)th host computer group to access the original base logical volume, or the current base logical volume, associated with the parallel access volume.

Abstract: An apparatus, system, and method are disclosed for accessing a preferred path through a storage controller. A request module receives a request from a host to identify a preferred path from the host to a control unit image. A response module reports the preferred path to the host. A connection module connects the host through the preferred path to the control unit image. In one embodiment, a detection module detects a failure of a first interconnection module comprising the preferred path. The connection module may re-connect the host to the control unit image through a non-preferred path comprising a second interconnection module in response to the failure of the first interconnection module.

Abstract: A communication-path management system includes a path-detection component for identifying all communications paths between a host computer, through a controller, to a data storage device. Once identified, the communication paths are incorporated into a logical-path mask. The path-detection component recognizes each path as either preferred or non-preferred based on latency, bandwidth, availability, or other user-defined criteria and divides the logical-path mask into a preferred path subset and a non-preferred path subset. If a valid path exists in the preferred path subset, all communications from the host computer to the data storage device transit paths belonging to this subset. Otherwise, active control is given to the non-preferred path subset. A channel subsystem manages actual communication based on resource allocation and contention using the currently active subset.

Abstract: A data storage system includes a host computer, a data storage device, and a communication bus connecting the host computer to the data storage device. The host computer is adapted to issue a specialized initiation command, such as a format command with a unique parameter or a unique send diagnostic command. Once received by the data storage device, the specialized initiation command is decoded by a command processor which, in turn, directs a memory controller to execute an internal initiation of target sectors residing on data storage media within the data storage device. The memory controller places sector data in a temporary memory device, such as a random-access memory (“RAM”), including a plurality of zeroes appended to a logical redundancy check (“LRC”) value. Once compiled, this sector data is written to the data storage media. In this way, target sectors of the data storage media are initialized with LRC information without requiring large amounts of data being transmitted over the communication bus.

Abstract: A log-in resource release system includes a set of lists for managing log-in requests to a processing cluster input/output port from host server input/output ports. Host servers that have been granted memory structures within a memory storage device (“configured hosts”) are granted priority access to a storage processing device's input/output port (“cluster port”). If the cluster port has exhausted its log-in resources, log-on requests from non-configured hosts will be not be accepted. New log-in requests from configured hosts will cause a host connected at a link or transport layer but not an upper layer to be logged off. If no hosts are connected only at the link or transport layer, a non-configured host connected at an upper layer will be logged off. If only configured hosts are connected and only at the upper layer, the log-on request by the configured host will be denied.

Abstract: When data is stored in many storage subsystems, metadata, such as a sequence number, is also generated and stored with the data. When the data is accessed, the metadata is checked to ensure that the desired data element has been accessed. In conventional storage subsystems, data elements, such as logical blocks, are stored sequentially in logical pages of each logical volume. Consequently, sequence numbers closely correlate with block positions within the physical pages and sequence number/position patterns tend to repeat frequently and access errors may not be detected. Algorithms are provided to calculate new, offset, physical block positions which reduce the close association of sequence numbers and physical positions, thereby reducing such aliasing. The algorithms incorporate the logical volume number, the logical page number, or both, in addition to the logical block number. As a result, detection of access errors becomes more likely.

Abstract: A feature key is provided to enable a specific feature in a target system, such as an IBM® Enterprise Storage Server®. The key includes fields identifying at least a portion of a serial number of the target system, identifying the feature on the target system to be enabled, and identifying a quantity associated with the feature to be enabled. Including the serial number ensures that the feature key will enable the feature on only the designated system and including the quantity ensures that only the quantity (of storage space, for example) paid for by the customer will be enabled. Additional fields may also be included identifying a storage architecture on which the feature is to be enabled, identifying a machine on which the feature is to be enabled, and identifying a sequence of prior feature keys generated for the feature on the target system.

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 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: A computer system includes a support system that report events, faults, and failures to a master virtual server. While the support system may be accessed and used by a multitude of virtual servers, only the master virtual server can manage the support system. The support system include a master lock register, a heartbeat timer, and a digital processing device (“processor”). Upon initialization and if the master lock register is empty, a virtual server asserts ownership over the support system by writing its identification into the master lock register, becoming the master virtual server. The master virtual server transmits periodic heartbeats to the support system to communicate that it is still viable and in control. If the heartbeat timer expires without communication from the master virtual server, the processor clears the master lock register and transmits a broadcast message inviting all connected virtual servers to attempt to assert control.

Abstract: Provided are a method, system, and program for managing volumes in volume groups configured in a storage system. A first set of volumes is assigned to a first volume group and a first host is assigned to the first volume group. A second set of volumes is assigned to a second volume group and a second host is assigned to the second volume group. The first host may only access volumes in the first volume group and the second host may only access volumes in the second volume group, wherein one volume is assigned to both the first and second volume groups to be accessible to both the first and second hosts.

Abstract: Provided are a method, system, and program for storing and using metadata in multiple storage location. Signature data is stored in a system storage indicating a plurality of metadata copy locations, each locating identifying a storage device and a copy location within the storage device. Each location contains one copy of the metadata, wherein the metadata includes system configuration information. A copy of the signature data is stored with each copy of the metadata.

Abstract: Provided are a method, system, and program maintaining and using nexus information on a host, port and device connection. A login is received from a host port on a storage controller port, wherein the host port has been configured on the storage controller to access one or more devices. An entry is added to a host-storage controller ports data structure for the host port and storage controller port involved in the login. At least one pointer is initialized in the entry in the host-storage controller ports data structure to point to at least one entry in at least one intermediate data structure. One pointer is initialized in each entry in one intermediate data structure addressed by one initialized pointer in the host-storage controller ports data structure to point to a nexi data structure having a plurality of entries.

Abstract: Provided are a method, system, and program for configuring volumes in a storage system. Information is provided on a plurality of storage device groups, wherein each storage group includes storage devices having common storage device attributes. Selection is received of at least one storage device group and an array type. An array is configured as the selected array type using storage devices included in the at least one selected storage group. Configured arrays are assigned to extent pools. A plurality of extents are configured in the extent pools, wherein each extent in one extent pool comprises a portion of one array assigned to the extent pool. A volume is configured to include at least one extent from one extent pool.

Abstract: An apparatus, system, and method are disclosed for facilitating copy protection. The apparatus includes a definition module, a request module, and a determination module, each coupled to a first storage sub-system. The definition module is configured to define a protection definition for a plurality of electronic storage devices of the first storage sub-system. The request module is configured to receive a copy request from a second storage sub-system. The determination module is configured to determine at the first storage sub-system a copy protection status of a destination device. The copy protection status may be indicated by the protection definition, which includes a protection indicator and may include one or more restriction indicators. The apparatus advantageously allows a user to protect a selected destination device against accidental or otherwise detrimental copying.

Abstract: A RAID system employs a storage controller, a primary storage array having a plurality of primary storage units, and a spare storage pool having one or more spare storage units. A method of operating the storage controller in managing the primary storage array and the spare storage pool involves a testing by the storage controller of at least one repair service threshold representative of one or more operational conditions indicative of a necessity to repair at least one of the primary storage array and the spare storage unit, and a selective initiation by the storage controller of a repair service action for repairing one of the primary storage array and the spare storage unit based on the testing of the at least one repair service threshold.