A system and method for generating synthetic data to simulate backing up data between a primary storage system and a protection storage system is presented. In one embodiment, a first track in a set of tracks is selected at random. Having selected a first track, at least a first block in the first track is modified. Subsequently, it is determined, based on a track run probability, whether to modify a second track that is consecutive to the first track or a third track that is selected randomly. Depending on the determination, at least one block is modified at either the second or third track. Other embodiments are also described herein.