摘要:
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.
摘要:
Provided are a method, system, and program for forming a consistency group of data. Information is provided on a consistency group relationship indicating a plurality of slave controllers and, for each indicated slave controller, a slave storage unit managed by the slave controller. A command is transmitted to each slave controller in the consistency group relationship to cause each slave controller to transmit data in the slave storage unit to a remote storage in a manner that forms the consistency group. A determination is made as to whether all the slave controllers successfully transmitted the data in the slave storage units that is part of the consistency group to the remote storage.
摘要:
Provided are a method, system, and program for forming a consistency group of data. Information is provided on a consistency group relationship indicating a plurality of slave controllers and, for each indicated slave controller, a slave storage unit managed by the slave controller. A command is transmitted to each slave controller in the consistency group relationship to cause each slave controller to transmit data in the slave storage unit to a remote storage in a manner that forms the consistency group. A determination is made as to whether all the slave controllers successfully transmitted the data in the slave storage units that is part of the consistency group to the remote storage.
摘要:
Disclosed is a technique for maintaining consistency of data. One or more blocks of data identified by a first structure are copied to form a consistent set of data. While not acknowledging completion of write requests to any blocks of data, a second structure is created, wherein the second structure indicates which blocks of data are modified while the consistent set of data is being formed. Also disclosed is a technique for asynchronous copy. Indicators are updated in a first structure for one or more blocks of data, wherein each indicator in the first structure indicates whether a corresponding block of data was modified since the block of data was last sent to remote storage. While copying the blocks of data identified by the indicators in the first structure as having been modified since the blocks of data were last sent to remote storage, indicators in a second structure are updated for the one or more blocks of data, wherein each indicator in the second structure indicates whether a corresponding block of data was modified while a consistent set of data is being formed.
摘要:
Disclosed is a method, system, and program for managing metadata in cache. A first policy is used to determine when to remove data from a primary cache, and a second policy is used to determine when to remove data from a metadata cache.
摘要:
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.
摘要:
A method for managing a data storage system includes copying data stored on a first storage subsystem to a second storage subsystem in an asynchronous mirroring process. A record is maintained on the second storage subsystem, indicative of locations at which the data have been updated on the first storage subsystem and have not yet been copied to the second storage subsystem. Upon receiving at the second storage subsystem, from a host processor, a request to access the data stored at a specified location on the data storage system, if the specified location is included in the record, the second storage subsystem initiates a synchronous transfer of the data at the specified location from the first storage subsystem.
摘要:
A method for managing a data storage system includes maintaining a record on a secondary storage subsystem, which is predictive of locations to which data are to be written on a primary storage subsystem by a host processor. Upon receiving at the primary storage subsystem, from a host processor, the data to be written to a specified location, if the specified location is not included in the record, the primary storage subsystem sends to the secondary storage subsystem so as to cause the secondary storage subsystem to update the record. The primary storage subsystem signals the host processor that the data have been stored in the data storage system responsively to receiving the data and to receiving an acknowledgment from the secondary storage subsystem indicating that the record has been updated.
摘要:
A method for managing a data storage system includes copying data stored on a first storage subsystem to a second storage subsystem in an asynchronous mirroring process. A record is maintained on the second storage subsystem, indicative of locations at which the data have been updated on the first storage subsystem and have not yet been copied to the second storage subsystem. Upon receiving at the second storage subsystem, from a host processor, a request to access the data stored at a specified location on the data storage system, if the specified location is included in the record, the second storage subsystem initiates a synchronous transfer of the data at the specified location from the first storage subsystem.
摘要:
The present invention provides a method, an apparatus and a computer program product for transferring a digital object from a source to a destination. The method includes splitting the digital object into a plurality of parts forming a first set of parts and a set of remaining parts. The method creates a credential record defining a relationship between the plurality of parts. The credential record includes retrieval information for the set of remaining parts. The method further includes transferring a first set of the parts along with the credential record to the destination using at least one push path. The method further includes fetching the set of remaining parts at the destination using the credential record to connect the destination to the source via at least one pull path. Further, the method includes recreating the digital object at the destination using the first set of parts, the credential record and a set of remaining parts.