1. A method of restoring a source volume to a previous point in time data state, comprising: receiving a signal that identifies a source volume and a first target snapshot that represents a point in time copy of the source volume; updating metadata to define a restore relationship between the first target snapshot and the source volume; executing a background copy process between the first target snapshot and the source volume; and managing input/output operations during the background copy process to permit input/output operations to the source volume during the background copy process.