Abstract: In one aspect of the present description, at least one of the value of a prestage trigger and the value of the prestage amount, may be modified as a function of the drive speed of the storage drive from which the units of read data are prestaged into a cache memory. Thus, cache prestaging operations in accordance with another aspect of the present description may take into account storage devices of varying speeds and bandwidths for purposes of modifying a prestage trigger and the prestage amount. Still further, a cache prestaging operation in accordance with further aspects may decrease one or both of the prestage trigger and the prestage amount as a function of the drive speed in circumstances such as a cache miss which may have resulted from prestaged tracks being demoted before they are used.

Abstract: In one embodiment of the present description, a copy relationship is established between a storage location at a first site and a storage location at a second site in a data storage system, wherein a dynamically assignable bitmap preset to one of a plurality of different predetermined bit patterns is selected as a function of both the availability of the selected bitmap and the type of predetermined bit pattern identified for the selected bitmap. The selected bitmap may be assigned as an out-of-sync bitmap wherein updates to the storage location at one site, which are to be copied to the storage location at the other site, are indicated in the selected bitmap, and data writes being written to the storage location at the one site, are copied to the storage location at the other site, using the selected bitmap as an out-of-sync bitmap. Other aspects are described.

Abstract: Provided are a computer program product, system, and method for managing updates and copying data in a point-in-time copy relationship expressed as source logical addresses and target logical addresses. A copy relationship indicates a source set of a subset of source logical addresses to copy to a target set comprising a subset of target logical addresses. An update is received to a source logical address that has not been copied. Determinations are made of the target logical address corresponding to the source logical address to be updated according to the copy relationship, a target group of target logical addresses in the target set that include the determined target logical address, and the source logical addresses in the source set that correspond to the target logical addresses in the target group. The determined source logical addresses are copied to the target logical addresses in the determined target group.

Abstract: Provided are a computer program product, system, and method for processing a copy command indicating a source set comprising a subset of source logical addresses to copy to an indicated target set comprising a subset of target logical addresses. Complete is expected to be returned to the copy command in response to completing the copying of the source set to the target set. A point-in-time (PiT) copy establish command is generated in response to receiving the copy command, indicating the source and target sets in the copy command, The generated PiT copy command is executed to generate copy information indicating the source and target sets of source logical addresses and whether they have been copied to the target set. Complete is returned to the copy command after generating the copy information and before copying all the source logical addresses to the target logical addresses.

Abstract: Provided are a computer program product, system, and method for processing a copy command indicating a source set comprising a subset of source logical addresses to copy to an indicated target set comprising a subset of target logical addresses. Complete is expected to be returned to the copy command in response to completing the copying of the source set to the target set. A point-in-time (PiT) copy establish command is generated in response to receiving the copy command, indicating the source and target sets in the copy command, The generated PiT copy command is executed to generate copy information indicating the source and target sets of source logical addresses and whether they have been copied to the target set. Complete is returned to the copy command after generating the copy information and before copying all the source logical addresses to the target logical addresses.

Abstract: A plurality of logical volumes are stored at a plurality of sites. A command to execute an operation on a logical volume is received. A determination is made as to whether a rule associated with the logical volume permits execution of the operation on the logical volume. In response to determining that the rule associated with the logical volume permits execution of the operation on the logical volume, the operation is executed on the logical volume.

Abstract: A plurality of logical volumes are stored at a plurality of sites. A command to execute an operation on a logical volume is received. A determination is made as to whether a rule associated with the logical volume permits execution of the operation on the logical volume. In response to determining that the rule associated with the logical volume permits execution of the operation on the logical volume, the operation is executed on the logical volume.

Abstract: In one embodiment of the present description, a copy relationship is established between a storage location at a first site and a storage location at a second site in a data storage system, wherein a dynamically assignable bitmap preset to one of a plurality of different predetermined bit patterns is selected as a function of both the availability of the selected bitmap and the type of predetermined bit pattern identified for the selected bitmap. The selected bitmap may be assigned as an out-of-sync bitmap wherein updates to the storage location at one site, which are to be copied to the storage location at the other site, are indicated in the selected bitmap, and data writes being written to the storage location at the one site, are copied to the storage location at the other site, using the selected bitmap as an out-of-sync bitmap. Other aspects are described.

Abstract: In accordance with one aspect of the present description execution of a particular command by a data processor such as a storage controller, may include obtaining priority over a resource which is also associated with execution of another command, setting a timer for the duration of a dynamically set timeout period, and detecting a potential deadlock condition as a function of expiration of the dynamically set timeout period before execution of the particular command is completed. In one embodiment, the particular command releases priority over the resource upon detection of the potential deadlock condition, and then reobtains priority over the resource in a retry of the command. It is believed that such an arrangement can relieve a potential deadlock condition, allowing execution of one or more commands including the particular command to proceed. Other features and aspects may be realized, depending upon the particular application.

Abstract: A plurality of logical volumes are stored at a plurality of sites. A command to execute an operation on a logical volume is received. A determination is made as to whether a rule associated with the logical volume permits execution of the operation on the logical volume. In response to determining that the rule associated with the logical volume permits execution of the operation on the logical volume, the operation is executed on the logical volume.

Abstract: A plurality of logical volumes are stored at a plurality of sites. A command to execute an operation on a logical volume is received. A determination is made as to whether a rule associated with the logical volume permits execution of the operation on the logical volume. In response to determining that the rule associated with the logical volume permits execution of the operation on the logical volume, the operation is executed on the logical volume.

Abstract: A storage controller receives a write command with respect to a track, from a host. A first process determines that the track is a source track and also determines that at least one corresponding target track is in an incremental copy relation to the source track. A second process is generated to modify a target change recording structure, where the second process executes in parallel with the first process.

Abstract: In one aspect of the present description, at least one of the value of a prestage trigger and the value of the prestage amount, may be modified as a function of the drive speed of the storage drive from which the units of read data are prestaged into a cache memory. Thus, cache prestaging operations in accordance with another aspect of the present description may take into account storage devices of varying speeds and bandwidths for purposes of modifying a prestage trigger and the prestage amount. Other features and aspects may be realized, depending upon the particular application.

Abstract: A plurality of logical volumes are stored at a plurality of sites. A command to execute an operation on a logical volume is received. A determination is made as to whether a rule associated with the logical volume permits execution of the operation on the logical volume. In response to determining that the rule associated with the logical volume permits execution of the operation on the logical volume, the operation is executed on the logical volume.

Abstract: A plurality of logical volumes are stored at a plurality of sites. A command to execute an operation on a logical volume is received. A determination is made as to whether a rule associated with the logical volume permits execution of the operation on the logical volume. In response to determining that the rule associated with the logical volume permits execution of the operation on the logical volume, the operation is executed on the logical volume.

Abstract: A request is received to perform a point in time copy operation from a source volume to a space efficient target volume. A controller copies data stored in a group of data storage units, from the source volume to a non-volatile storage, to preserve the point in time copy operation. A background process asynchronously copies the data from the non-volatile storage to the space efficient target volume to commit a physical point in time copy of the data from the source volume to the target volume.

Abstract: A request is received to perform a point in time copy operation from a source volume to a space efficient target volume. A controller copies data stored in a group of data storage units, from the source volume to a non-volatile storage, to preserve the point in time copy operation. A background process asynchronously copies the data from the non-volatile storage to the space efficient target volume to commit a physical point in time copy of the data from the source volume to the target volume.

Abstract: Provided are a computer program product, system, and method for quiescing Input/Output (I/O) requests to subsets of logical addresses in a storage for a requested operation. A requested operation is received to a subset of addresses in the storage that requires that Input/Output (I/O) requests to the subset of addresses received following the requested operation be quiesced. The subset of addresses is indicated in quiesce information. I/O requests received following the receiving of the requested operation are quiesced when one address subject to the I/O request is included in the subset of addresses. If there are in-progress I/O requests pending against the subset of addresses when the requested operation was received, then the requested operation is indicated as executable. A quiesced I/O request is executed when no address subject to the quiesced I/O request is included in the subset of addresses indicated in the quiesce information.

Abstract: Provided are a computer program product, system, and method for quiescing Input/Output (I/O) requests to subsets of logical addresses in a storage for a requested operation. A requested operation is received to a subset of addresses in the storage that requires that Input/Output (I/O) requests to the subset of addresses received following the requested operation be quiesced. The subset of addresses is indicated in quiesce information. I/O requests received following the receiving of the requested operation are quiesced when one address subject to the I/O request is included in the subset of addresses. If there are in-progress I/O requests pending against the subset of addresses when the requested operation was received, then the requested operation is indicated as executable. A quiesced I/O request is executed when no address subject to the quiesced I/O request is included in the subset of addresses indicated in the quiesce information.

Abstract: Provided are a computer program product, system, and method for managing updates and copying data in a point-in-time copy relationship expressed as source logical addresses and target logical addresses. A copy relationship indicates a source set of a subset of source logical addresses to copy to a target set comprising a subset of target logical addresses. An update is received to a source logical address that has not been copied. Determinations are made of the target logical address corresponding to the source logical address to be updated according to the copy relationship, a target group of target logical addresses in the target set that include the determined target logical address, and the source logical addresses in the source set that correspond to the target logical addresses in the target group. The determined source logical addresses are copied to the target logical addresses in the determined target group.