Parallel computation on cluster architectures has become the most common solution for developing high-performance scientific applications. Message Passing Interface (MPI) is the message-passing library most widely used to provide communications in clusters. Along the I/O phase, the processes frequently access a common data set by issuing a large number of small non-contiguous I/O requests, which might create bottlenecks in the I/O subsystem. These bottlenecks are still higher in commodity clusters, where commercial networks are usually installed. Scalability is also an important issue in...