Patent ID: 7240172

Claim:
A method comprising: receiving a command to create a point-in-time copy of an original data store, the original data store stored to a parent virtual logical unit (VLU) having associated therewith a deferred propagation data structure, the deferred propagation data structure capable of containing a plurality of data propagation records and a plurality of separators, each data propagation record containing a previous version of one or more data blocks of the parent VLU, each separator containing a pointer to a particular child VLU storing a point-in-time copy of the original data store and separating the data propagation records pertaining to the particular child VLU; creating a child VLU to store the point-in-time copy of the original data store; entering a new separator into the data propagation data structure, the new separator containing a pointer to the child VLU; and implementing a search pointer in the child VLU, the search pointer pointing to the deferred propagation data structure.