Network function virtualization (NFV) is a promising technology that has attracted much attention in both academia and industry. With IT resource virtualization, NFV paradigm could decouple network functions (NFs) from special-purpose hardware equipment, providing more flexibility to network service providers and facilitating a better sharing of physical infrastructure when implementing NFs. Meanwhile, with the introduction of flexible-grid elastic optical networks (EONs) and virtualized transponders (vTPs), a new concept of resource virtualized elastic optical networks (RvEON) is emerged in this context, which has not only realized link-tier spectrum virtualization in each fiber link, but also realized node-tier TP virtualization within each substrate node. In this paper, we for the first time study how to implement efficient virtual network function service chaining (VNF-SC) in inter-DC RvEONs, taking into account subcarrier and modulation resources of the vTPs equipped in network nodes, in addition to fiber-link spectrum and IT resources. First, an integer linear programming (ILP) model for the VNF-SC deployment problem is formulated for jointly allocating these multi-dimensional resources. Then, for scalability, we also propose a heuristic based on Maximum Reuse with Decentralization Principle (MR-DP). The main idea behind the heuristic is that deploying the VNFs in a much more load-balanced manner can facilitate to maximize reuse the most existing VNFs to save the IT resources. The simulation results indicate that the proposed MR-DP heuristic can allow the minimum number of the deployed VNFs, while consuming the similar amount of other resources, compared with other two benchmark schemes.