Abstract: Host input/output (I/O) operations are performed via a file stored in a non-volatile storage coupled to a storage controller while data structures are being generated in the storage controller to copy data from source logical volumes to target logical volumes. The source logical volumes and the target logical volumes are logical representations of physical storage maintained in a plurality of direct access storage devices. The contents of the file are transferred from the non-volatile storage to one or more of the plurality of direct access storage devices, after the data structures have been generated, wherein the host I/O operations are performed via the file while the contents of the file are being transferred to the one or more of the plurality of direct access storage devices. The host I/O operations to the plurality of direct access storage devices are resumed, in response to transferring entire contents of the file to the one or more of the plurality of direct access storage devices.

Abstract: A method to store point-in-time data, comprising establishing a block size, providing source data storage comprising (S) blocks, and target data storage comprising (T) blocks. The method configures (B) source storage segments and (B) target storage segments, and receives updated point-in-time data for original point-in-time data written to an (i)th source storage segment. The method then determines if a (j)th target storage segment comprises available storage capacity to store the original point-in-time data. If a (j)th target storage segment comprises available storage capacity to store the original point-in-time data, the method writes the original point-in-time data to that (j)th target storage segment.

Abstract: Provided are techniques for introducing a delay in responding to host write requests. A percentage of fullness of a write cache is determined. Based on the determined percentage of fullness of the write cache (f), a low cache threshold (L), alpha (?), and k, an amount of delay to introduce into responding to a host write request is determined. Techniques wait the amount of the delay before responding to the host write request although the host write request processing has completed.

Abstract: Provided are techniques for introducing a delay in responding to host write requests. A percentage of fullness of a write cache is determined. Based on the determined percentage of fullness of the write cache (f), a low cache threshold (L), alpha (?), and k, an amount of delay to introduce into responding to a host write request is determined. Techniques wait the amount of the delay before responding to the host write request although the host write request processing has completed.

Abstract: Host input/output (I/O) operations are performed via a file stored in a non-volatile storage coupled to a storage controller while data structures are being generated in the storage controller to copy data from source logical volumes to target logical volumes. The source logical volumes and the target logical volumes are logical representations of physical storage maintained in a plurality of direct access storage devices. The contents of the file are transferred from the non-volatile storage to one or more of the plurality of direct access storage devices, after the data structures have been generated, wherein the host I/O operations are performed via the file while the contents of the file are being transferred to the one or more of the plurality of direct access storage devices. The host I/O operations to the plurality of direct access storage devices are resumed, in response to transferring entire contents of the file to the one or more of the plurality of direct access storage devices.

Abstract: A method to store point-in-time data, comprising establishing a block size, providing source data storage comprising (S) blocks, and target data storage comprising (T) blocks. The method configures (B) source storage segments and (B) target storage segments, and receives updated point-in-time data for original point-in-time data written to an (i)th source storage segment. The method then determines if a (j)th target storage segment comprises available storage capacity to store the original point-in-time data. If a (j)th target storage segment comprises available storage capacity to store the original point-in-time data, the method writes the original point-in-time data to that (j)th target storage segment.