Santa Clara-based Sun Microsystems said this morning that it is in a definitive agreement to acquire Cluster File Systems, Inc., developer of the Lustre File System, a Unix clustered file system. Financial terms were not disclosed. Cluster File Systems, which is based in Boulder, Colorado, maintains and developed Lustre as an open source distributed file system project; Lustre was being used in the supercomputing industry by supercomputing centers such as Oak Ridge National Laboratory, Lawrence Livermore, and other research labs. Sun said it plans to continue enhancing Lustre on Linux and Solaris. The deal is expected to close in October.