Disk-based storage is becoming increasingly problematic in meeting the needs of large-scale cloud applications. Recently RAM-based storage is proposed by aggregating the RAM of thousands of commodity servers in Data Center Networks (DCN). These studies focus on improving performance with low latency RPC and fast failure recovery. RAM-based storage brings great DCNrelated challenges, e.g., false server failure detection due to network problems, traffic congestion during failure recovery, and ToR switch failure handling. This paper presents RAMCube, a DCN-oriented design for RAM-based key-value store based on the BCube network.