Distributed data storage systems (DSS) are multi-parameter, complexly configurable systems. Fault tolerance and reliability of DSS data storage are ensured by a set of different methods. To assess the efficiency of new methods, it is convenient to use software tools that simulate the operation of DSS. The purpose of this work is to study the existing software simulators of DSS to assess the potential of their use. The study is based on the analysis of several software simulators that model the operation of DSS. The analysis took into account such parameters as the choice of the redundancy introduction method, the data placement method, the data recovery algorithm after failure, and the choice of storage architecture. The results of the study show that simulators offer a wide range of options for modeling fault tolerance, but some of them demonstrate greater efficiency in some scenarios. A generalized structural diagram of the simulators is built, revealing the features of the architecture and principles of operation. The CR-SIM simulator has the greatest functionality, but its source codes and executable file are not available. Simulators with open source code do not have a flexible architecture for their expansion with new methods. The сonclusion is made about the need to develop a new simulator in the form of an open source software tool, the architecture of which is designed for its expansion. Such a simulator will allow testing new developments in the field of fault tolerance enhancement technologies.

Keywords: data storage system, fault tolerance, erasure codes, software simulator, dependability, simulation model