The required real-time and high-rate transfers for multimedia data severely limit the number of requests that can be serviced by Video-on-Demand (VOD) servers. Resource sharing techniques can be used to address this problem. We evaluate through extensive simulation major resource sharing techniques, considering both the True Video-on- Demand (TVOD) and Near Video-on-Demand (NVOD) service models. Moreover, we propose a statistical approach for cache management and derive analytical models for optimal cache allocation to reduce the demands on the disk I/O when various resource sharing techniques are used.