Abstract: Provided are a method, system, and program for using a heartbeat signal to maintain data consistency for writes to source storage copied to target storage. A copy relationship associates a source storage and target storage pair, wherein writes received at the source storage are transferred to the target storage. A determination is made whether a signal has been received from a system within a receive signal interval. A freeze operation is initiated to cease receiving writes at the source storage from an application in response to determining that the signal has not been received within the receive signal interval. A thaw operation is initiated to continue receiving write operations at the source storage from applications after a lapse of a freeze timeout in response to the freeze operation, wherein after the thaw operation, received writes completed at the source storage are not transferred to the target storage.

Abstract: Provided are a method, system, and article of manufacture, wherein a primary control unit sends a selected time to a plurality of secondary control units. Clocks are periodically synchronized at the primary control unit and the secondary control units with a time server. The primary control unit and the plurality of secondary control units consistently update secondary storage subsystems coupled to the plurality of secondary control units at the selected time.

Abstract: Provided are a method, system, and program for remote copying of updates to primary and secondary storage locations subject to a copy relationship. A first copy relationship is established between first and second storage locations in a first storage system and second storage system, respectively, wherein updates to the first storage locations are copied to the second storage locations. A second copy relationship is established between the first storage locations in the first copy relationship and third storage locations in a third storage system, wherein updates to the first storage locations are indicated in a first bitmap. A suspended third copy relationship is established between the second storage locations in the first copy relationship and the third storage locations, wherein updates to the second storage locations are indicated in a second bitmap.

Abstract: Provided are a method, system, and program for consolidating session information for a cluster of sessions in a coupled session environment. Information for each of a plurality of sessions comprising a cluster is stored in a memory of a processor session. Each session associates at least one primary system and at least one secondary system, wherein within each session, updates are copied from the at least one primary system to the at least one secondary system. The session information in the memory for the plurality of sessions is processed to generate consolidated session information for the cluster based on the session information for the sessions in the cluster. The consolidated session information for the cluster is written to a master data set maintaining information for sessions.

Abstract: Provided are a method, system, and article of manufacture wherein a command is received for writing data to a first storage location. A determination is made that previously written data is stored in the first storage location. The previously written data is copied to a second storage location, in response to determining that the previously written data is stored in the first storage location. The data is written to the first storage location, in response to copying the previously written data to the second storage location.

Abstract: Provided are a method, system and program from managing failures in a mirrored system. A copy relationship between primary and secondary storage locations, wherein updates to the primary storage locations are copied to the secondary storage locations. A failure is detected preventing an application from writing updates to the primary storage locations. A failure message is received for the application in response to detecting the failure, wherein the failure message is not provided to the application. The copying of updates to the primary storage locations to the secondary storage locations is suspended. The failure message is provided to the application in response to suspending the copying.

Abstract: Provided are a method, system, and program for maintaining consistency when mirroring data using different copy technologies. Update groups having updates to primary storage locations are formed using a first copy technology. The updates in the update groups are copied to secondary storage locations. Update groups having updates to primary storage locations are formed using a second copy technology, wherein the updates in the update groups are copied to secondary storage locations. Indication is made in a data structure of a time of an update in response to including the update in one of the update groups formed using the first copy technology. Indication is also made in the data structure of a time of the update group formed using the second copy technology.

Abstract: An apparatus, system, and method are disclosed for continuously protecting data. A mirror module mirrors a primary record set to a base record set. A log module accumulates each record change to the primary record set in a log. A change selection module selects a record change from the log. A change application module applies the selected record change to the base record set to form a recovered record set.

Abstract: A method is disclosed to provide commands to an information storage and retrieval comprising one or more data storage devices, where one or more first communication links interconnect one or more host computers and the data storage and retrieval system. The method supplies a computing device, where that computing device is external to the data storage and retrieval system, and where that computing device is external to each of the one or more host computers. Applicants' method further supplies a second communication link interconnecting the computing device and the data storage and retrieval system. The computing device generates a command signal, where said command signal comprises one or more command control words and a header. The computing device then provides that command signal to the data storage and retrieval system via the second communication link.

Abstract: Provided are a method, system, and program for processing a transaction. Transaction data is transmitted from one primary storage site to a plurality of secondary storage sites. A transaction request is received at one secondary storage site and processed to include transaction data from the secondary storage site that was transmitted from the primary storage site. The processed transaction request including transaction data is transmitted from the secondary storage site to the primary storage site to approve the transaction. The transaction request at the primary storage site is approved if the transaction data included in the received transaction request is consistent with the transaction data maintained at the primary storage site.

Abstract: Provider are a method, system, and program for maintaining data in a distributed computing environment. Data is stored at a primary storage site. A data structure is processed indicating an association of data sets in the stored data, secondary storage sites, and update frequencies. In response to processing the data structure, a determination is made of one of a plurality of secondary storage sites and a determination is made of at least one data set to transmit to the determined secondary storage site at an update frequency. The determined data set is transmitted to the determined secondary storage site according to the update frequency.

Abstract: Techniques are provided for processing a request. When the request is to read a data unit, information regarding the closest physical block locations is returned. When the request is to write to the data unit, information regarding one or more source block locations is returned, wherein the write is applied to one or more source blocks of the data unit. When a number of requests for the data unit exceed a threshold level and at least one quality of a service policy is not being met, a copy of the one or more source blocks of the data unit is created at a location selected based on proximity to at least one client computer from which the number of requests are high.

Abstract: Techniques are provided for locating data. Mapping information for blocks associated with a file is provided. It is determined that a copy service has copied source blocks to target blocks. It is determined whether the mapping information should be updated to refer to the target blocks. Then, updated mapping information is provided in response to determining that the mapping information should be updated to refer to the target blocks. Techniques are also provided for accessing a copy of data when a source of the data is inaccessible. It is determined that source blocks are unavailable. Target blocks that are a copy of the unavailable source blocks are located using data in a metadata store. Indicators pointing to the source blocks are switched to point to the target blocks. Mapping information is updated at one or more client computers to access the target blocks instead of the source blocks.

Abstract: Techniques are provided for distributing data. It is determined that a source storage device is becoming a bottleneck. One or more blocks to be moved from the source storage device to one or more other storage-devices are identified. The one or more other storage devices are selected. Copy services are used to move the blocks from the source storage device to the one or more other storage devices. A metadata store is updated with locations of the blocks that have been moved.

Abstract: Disclosed is a technique for performing configuration checking of a network. A network data store is scanned for at least one transaction. At least one event is generated for said transaction. At least one configuration policy is associated with said event. Said configuration policy is compared with configuration data associated with said event. It is determined whether said configuration policy has been violated based on the comparison. Also disclosed is a technique for performing proactive configuration checking of a network. A hypothetical network scenario is received. At least one transaction is generated based on the hypothetical network scenario. A network data store is populated with configuration data for said transaction. At least one event is generated for said transaction using a mapping of events to transactions. Configuration data associated with said event is used to determine whether a configuration policy has been violated.

Abstract: Provided are a method, system, and article of manufacture for copying storage, wherein a first unit receives data updates from a second unit. The data updates are stored in a plurality of physical storage locations associated with the first unit. Links are generated to at least one of the plurality of physical storage locations to achieve consistent data between the first unit and the second unit.

Abstract: The invention automatically selects a copy function according to a policy associated with data to be copied. The apparatus comprises an identification module configured to identify available copy functions in response to a data copy request that includes a predefined copy policy, a comparison module configured to compare each copy function of a storage device to attributes of the predefined copy policy, a selection module configured to automatically select a copy function that satisfies the predefined copy policy, and a relationship module configured to establish a copy relationship between the determined copy function and the data copy request. A policy generation module may be included and configured to read a set of required attributes from an application and to establish the predefined copy policy based on the set of required attributes from the application.

Abstract: A computer program for automatically pairing target resources 20 such as volumes or logical units to source resources 20 containing data to be copied. Available target pools 48, 50, 52, 54 of target volumes are determined eligible for copying based on a technical compatibility and a user-defined metric such as recovery point or recovery time. User defined metrics and a policy to implement the metrics may be stored in a medium and selected by a user. The source volumes are prioritized, and progressively larger segments of the eligible target pools are searched for a target volume that satisfies the technical compatibility and user-defined metric. Where subgroups such as nested volumes are present in the source volumes, subgroups are also prioritized for searching. Where no target volume can be paired, the corresponding source volume is marked as processed and a search begins for the next source volume.