Abstract: Provided are a method, system, and article of manufacture, wherein a controller receives a request from one of a plurality of hosts. The controller determines whether a primary storage control unit coupled to the controller is operational. A response is generated by accessing the primary storage control unit, in response to determining that the primary storage control unit is operational. The response is generated by accessing a secondary storage control unit, in response to determining that the primary storage control unit is not operational, wherein data is replicated synchronously from the primary storage control unit to the secondary storage control unit.

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: The present invention is directed to a batch process for synthesizing rubbery polymers, such as styrene-butadiene rubber, having a high trans microstructure. In one embodiment, the batch process involves mixing a catalyst system with styrene and butadiene monomers in a single reactor, with additional butadiene monomer being added after a desired period of time to further drive styrene conversion and, thus, provide a desirable high trans rubbery polymer, e.g., styrene-butadiene rubber. The copolymerization process can be conducted at a temperature in the range of about 20° C. to about 180° and over a period of about 1 to about 4 hours. The catalyst system can include (a) an organolithium compound, (b) a group IIa metal salt, and (c) an organoaluminum compound. The catalyst system may further optionally include an amine compound and/or an organomagnesium compound.

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, system, and method are disclosed for determining prefetch data. A start module communicates a start of a target software process to a storage device. A learning module learns data blocks accessed for the target software process. In one embodiment, a prefetch module prefetches the learned data blocks in response to the start of the target software process. An end module communicates the end of the target software process to the storage device. In one embodiment, the prefetch module terminates prefetching data blocks and the learning module terminates learning the data blocks accessed for the target software process in response to the end module's communication of the end of the target software process.

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: Disclosed is a technique for data synchronization. A first identifier for a portion of data on a primary volume is determined, wherein a unique identifier is associated with each portion of data at the primary volume. A second identifier for a portion of corresponding data at a secondary volume is determined, wherein a unique identifier is associated with each portion of data at the secondary volume. The first and second identifiers are compared. When the first and second identifiers do not match, the portion of corresponding data at the secondary volume in a storage device is replaced with the portion of data at the primary volume.

Abstract: Provided are a method, system, and program for establishing copy relationships to copy source data to target data. A request is received to establish a copy relationship indicating to copy source data to target data. A determination is made as to whether the source data defined in the request comprises target data defined in a preexisting copy relationship. A determination is made as to whether base source data copied to the target data in the preexisting copy relationship also comprises the source data indicated in the request in response to determining that the source data defined in the request comprises target data in the preexisting copy relationship. A new copy relationship is defined to copy the determined base source data to the target data indicated in the request.

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: 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 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: Methods and apparatus are provided for copying data from a primary storage facility to a secondary storage facility which reduce the workload on the storage controller in the primary facility and minimize bandwidth usage. The primary storage facility includes a primary data replication appliance which transfers data to a secondary replication appliance. Updated data from a host is both stored through a storage controller in the primary facility and also received by the primary replication appliance. Logic in the primary replication appliance determines whether the immediately previous version of the data is in a buffer from a previous storage operation. If so, the current (updated) version of the data is compared with the previous version and the difference, such as calculated through a bit-wise exclusive-OR operation, is transferred to the secondary replication appliance.

Abstract: Provided are a method, system, and article of manufacture, wherein data and metadata are generated in a computational device, wherein the generated data is stored in a first physical storage device coupled to the computational device, and wherein the generated metadata is stored transiently in the computational device. The data and the metadata are replicated to a second physical storage device. The replicated data and the replicated metadata in the second physical storage device are used to recover from a failure of at least one of the computational device and the first physical storage device.

Abstract: Provided are a method, system, and article of manufacture, wherein a controller receives a request from one of a plurality of hosts. The controller determines whether a primary storage control unit coupled to the controller is operational. A response is generated by accessing the primary storage control unit, in response to determining that the primary storage control unit is operational. The response is generated by accessing a secondary storage control unit, in response to determining that the primary storage control unit is not operational, wherein data is replicated synchronously from the primary storage control unit to the secondary storage control unit.

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: An apparatus, system, and method are disclosed for reliably updating a data group in a data replication environment. The apparatus, system, and method reliably update the data group by receiving an updated data group sent from a first storage medium to a second storage medium, comparing the updated data group with a previous data group previously existing on the second storage medium and writing the updated data group to the second storage medium. The read-before-write and differencing method disclosed maintain reliability by storing multiple copies of changes made to the second storage medium during and after the write process.

Abstract: An apparatus, system, and method are disclosed for efficient creation of point-in-time versions of data using differencing in a read-before-write environment. Included in an embodiment of the invention are a receive module that receives a data block sent from a primary data storage system, a read module that reads a data block from a secondary data storage device into random access memory, the data block corresponding to the data block sent from the primary data storage system, a comparison module that compares the data block sent from the primary data storage system to the data block from the secondary data storage device and creates a differencing data file, a compression module that compresses the differencing data file and to create a compressed differencing data file, and a differencing storage module stores the compressed differencing data file in a differencing storage device.

Abstract: Provided are a method, system and program for prefetching data into cache. A prefetch command is processed that indicates at least one conditional statement and at least one block to prefetch from storage to cache in response to determining that the conditional statement is satisfied.

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: Disclosed is a technique for transferring data using multiple backup components. Responsibility for a portion of data is assigned to a first backup component. When a data update for the portion of data is received at the first backup component from a primary source, the data update is mirrored to a second backup component that is not assigned responsibility for the portion of data. Also disclosed is a technique for processing data updates with a group of backup components. It is determined that a new backup component is active. Near an end of a consistent transactions set formation period, responsibility for one or more portions of data are assigned to each backup component in the group and to the new backup component. During a next consistent transactions set formation period, data updates are processed with each backup component in the group and the new backup component. Moreover, disclosed is a technique for processing data updates with a group of backup components.