The subject of this internship report is the performance evaluation of a Cluster file system called Lustre, before its installation into a computing Cluster, or other computing systems. Performance evaluation includes benchmarks, comparison to other file systems (ext3, NFS), and study of tuning possibilities. In this report we first present the file system Lustre, and then we explain how the tests were driven, including the methodology of the tests, the installation of the test platform, and a preliminary research of the main bottlenecks. Three types of benchmarks have been driven: read/write of big files, including both sequential and random access, in order to test the throughput; read/write of small files, in order to test the cache efficiency; and creation/deletion of empty files, in order to test the access times. The aim is to see in which cases it is convenient to use the Lustre file system.