This paper analyzes various distributed storage systems that use data fragmentation and dispersal as a way of protection.Existing solutions have been organized into two categories: bitwise and structurewise. Systems from the bitwise category are operating on unstructured data and in a uniform environment. Those having structured input data with predefined confidentiality level and disposing of a heterogeneous environment in terms of machine trustworthiness were classified as structurewise. Furthermore, we outline high-level requirements and desirable architecture traits of an eficient data fragmentation system, which will address performance (including latency), availability, resilience and scalability.