摘要:
An apparatus for optimizing a transaction comprising an initial sequence of computer operations, the apparatus includes a processing unit which identifies one or more idempotent operations comprised within the initial sequence, and which reorders the initial sequence to form a reordered sequence comprising a first sub-sequence of the computer operations followed by a second sub-sequence of the computer operations, the second sub-sequence comprising only the one or more idempotent operations.
摘要:
A method for optimizing a transaction consisting of an initial sequence of computer operations, the method including identifying one or more idempotent operations in the initial sequence. The method further includes reordering the initial sequence to form a reordered sequence consisting of a first sub-sequence of the computer operations followed by a second sub-sequence of the computer operations. The second sub-sequence has only the one or more idempotent operations.
摘要:
Provided are a method, system, and article of manufacture for copying storage. Copy operations are performed on source storage units to copy to target storage units, wherein the copy operations create a consistent copy of the source storage units in the target storage units. While performing a copy operation to copy from one source storage unit to one target storage unit, a write operation is restricted from being performed on the one source storage unit, until the copy operations have been performed on the source storage units.
摘要:
Techniques are provided for performing a copy operation. A fast reverse restore command indicating a new source and a new target is received, wherein the new source is an original target and the new target is an original source. A synchronous scan is performed on the new target. A new target structure associated with the new target is updated using a new source structure associated with the new source.Techniques are also provided for performing a copy operation in which a fast reverse restore command is received after an instant virtual copy has been performed from a new target to a new source and wherein the fast reverse restore command is performed before a background copy has been performed by the instant virtual copy.
摘要:
Provided are a method, system, and article of manufacture for copying storage. Copy operations are performed on source storage units to copy to target storage units, wherein the copy operations create a consistent copy of the source storage units in the target storage units. While performing a copy operation to copy from one source storage unit to one target storage unit, a write operation is restricted from being performed on the one source storage unit, until the copy operations have been performed on the source storage units.
摘要:
Provided are a method, system, and program for managing a relationship between one target volume and one source volume. Information is maintained in memory on an existing relationship between at least one source volume and at least one target volume, comprising: (i) at least one element, wherein each element represents a range of sequential data units in the volume; (ii) at least one relationship entry, wherein each relationship entry represents one relationship; and (iii) at least one element pointer associating one element with one relationship entry, wherein the data units represented by the element are part of the relationship represented by the relationship entry that the pointer associates with the element. A new relationship between at least one target volume and at least one source volume is added. Further, added is a new relationship entry in the memory representing the new relationship and one new element pointer is added in the memory for each element including data units included in the new relationship to associate the element with the new relationship entry, wherein the data units represented by the element are part of the new relationship.
摘要:
Disclosed is a technique for applying changes back to an original copy of data to reduce an amount of data transferred. A first indicator is maintained for each block of data in a first storage to indicate whether the block of data has been updated in the first storage since the block of data was last transferred to a second storage. A second indicator is maintained for each block of data in the second storage to indicate whether the block of data has been updated in the second storage since the block of data in the second storage was overwritten by a corresponding block of data in the first storage. Upon receiving a reverse restore operation, each block of data in the second storage for which a second indicator has been set to indicate that the block of data has been updated is transferred to the first storage and each block of data in the second storage that corresponds to a block of data in the first storage for which a first indicator has been set to indicate that the block of data in the first storage has been updated is transferred to the first storage.
摘要:
Disclosed is a technique for reducing an amount of data transferred. A first indicator is maintained for each source block of data to indicate whether the source block of data has been updated in source storage since the source block of data was last transferred to target storage. A second indicator is maintained for each target block of data in target storage to indicate whether the target block of data has been updated in target storage since the target block of data was overwritten by a corresponding source block of data. When transferring data from the source storage to the target storage, each source block of data for which a first indicator has been set to indicate that the source block of data has been updated is transferred and each source block of data that corresponds to a target block of data for which a second indicator has been set to indicate that the target block of data has been updated is transferred.
摘要:
Generating a consistent point in time copy of data in a source volume and a target volume is achieved responsively to a first data modification request by writing a first altered version of the data onto a single source volume, asynchronously transferring the first altered version from the first storage site to a target volume located at a remote second storage site, while avoiding copying the first altered version onto other volumes at the first storage site. While asynchronously transferring the first altered version de-queuing a second modification request, and responsively to the second modification request synchronously transferring the first altered version from the first storage site to the target volume. Then a second altered version of the data is written to the single source volume and a copy transferred to the target volume in like manner.
摘要:
A method for generating a consistent point in time copy of data, the method includes: selecting at least one selected data block to be copied from a source volume to a target volume in response to a request to generate a consistent point in time copy of multiple data blocks; waiting until the source volume is ready to send the at least one selected data block to a remote volume while queuing at least one data block modify request; de-queuing the at least one queued modify requests while copying the at least one selected data block from the source volume to the target volume; wherein the copying includes utilizing a first copying mechanism to copy a first selected data block if a request to modify the first selected block is de-queued before the first selected data block is copied to the target volume; else, the copying includes using a second copying mechanism that is slower than the first copying mechanism.