When a cluster system interconnects processor and I/O nodes through a network, an optimal placement of I/O nodes is critical to improve the overall system performance by reducing its communication latency. In this paper, we propose an efficient and scalable I/O node placement scheme, called a relaxed quasi-perfect, for torusbased interconnection networks using Lee distance errorcorrecting code. It provides a more general placement than the previous quasi-perfect placement [1]. We also suggest a fault-tolerant scheme using our I/O placement model for a guaranteed performance. Simulation results show that our scheme provides 53% speed-up over the quasi-perfect. Also the fault tolerant scheme provides a graceful slowdown especially until the number of faulty I/O nodes becomes less than half of the initial I/O nodes.