This paper investigates the problem of network partitioning in Distributed Shared Memory (DSM) systems. We propose an optimistic-based partition-processing approach, which can make shared pages available when network partitioning occurs. However, this approach does not guarantee that the same page in different partitions can maintain a consistent value. To eliminate this problem, a memory-based coordinated checkpoininting scheme is presented to save consistent states at low cost. If there are inconsistencies between two partitions, one saved consistent state is chosen to perform backward error recovery. Extensive trace-driven simulations have been performed to evaluate the effects of the proposed approach on system performance.