Multi-target, point-in-time-copy architecture with data duplication

A method for performing a write to a source volume in a multi-target architecture is described. The multi-target architecture includes a source volume and multiple target volumes mapped thereto. In one embodiment, such a method includes copying data in a track of the source volume to a corresponding track of a target volume (target x). The method enables one or more sibling target volumes (siblings) mapped to the source volume to inherit the data from the target x. When the data is successfully copied to the target x, the method performs a write to the track of the source volume. Other methods for reading and writing data to volumes in the multi-target architecture are also described.