Cloud service providers (CSP) usually deploy geographically distributed data centers to improve QoS for colocated customers. Inter-Data center traffic constitutes almost half of the data center's export traffic and occupies significant part of the operational cost. Many store-and-forward mechanisms have been proposed to improve the efficiency of inter-data center transfer. However, existing store-and-forward solutions to the inter-datacenter traffic problem need sufficient and suitable intermediate nodes for transferring data, which is much more difficult for both the small and the big CSPs. In this paper, we present a shared datacenter scheduling mechanism called SSNF, which focus on providing more idle intermediates to increase the transmission success ratio for the inter-datacenter traffic. In SSNF, CSPs share datacenters which have idle storage resource and provide these idle datacenters as intermediate nodes for other CSP's data transmission. We compared our scheme with existing bulk data transfer mechanism under several different simulation settings. The results demonstrate our solution has a better transmission success ratio and achieves high efficiency for inter-datacenter traffic.