We present in this paper an evaluation of fault management in the grid middleware P2P-MPI. One of P2P-MPI's objective is to support environments using commodity hardware. Hence, running programs is failure prone and a particular attention must be paid to fault management. The fault management covers two issues: fault-tolerance and fault detection. P2P-MPI provides a transparent fault tolerance facility based on replication of computations. Fault detection concerns the monitoring of the program execution by the system. The monitoring is done through a distributed set of modules called failure detectors. In this paper, we report results from several experiments which show the overhead of replication, and the cost of fault detection.