Abstract The Gemini system is a replicated-file testbed facility designed for local area networks and is built using ordinary host unix machines. Gemini was designed to test empirically consistency and recovery schemes for replicated files in a distributed environment. A principle objective is to protect files against a fixed number of host and network failures while maintaining consistent data. Gemini replicated files are implemented as several copies of ordinary files that reside on distinct hosts. We present the Gemini system testbed design and discuss three consistency and recovery schemes: voting with witnesses, dynamic voting, and semisynchronous voting. Empirical and analytic performance results are presented.