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

A method for performing a read on a target volume (target x) in a multi-target architecture, the multi-target architecture comprising a source volume and a plurality of target volumes mapped thereto, the method comprising:

• reading a target bit map (TBM) associated with the target x;
• determining whether the TBM is set;
• if the TBM is set, reading data from a higher source (HS) volume, wherein reading data from the HS volume comprises:
• finding the source volume associated with the target x;
• finding, by inspecting generation numbers (GNs) on the source volume, the next younger sibling relative to the target x;
• and
• reading the data from the next younger sibling if a TBM associated with the next younger sibling is not set.

A method for performing a write to a source volume in a multi-target architecture, the multi-target architecture comprising a source volume and a plurality of target volumes mapped thereto, the method comprising:

• copying data in a track of the source volume to a target volume (target x) mapped to the source volume;
• enabling at least one sibling target volume (sibling) mapped to the source volume to inherit the data from the target x;
• and
• performing a write to the track of the source volume.