To reduce the service bandwidth consumption of a video-on-demand (VOD) system, a recursive patching idea is proposed and several on-line algorithms based on this idea are experimented with in this research. With a limited receiver buffer space, we adopt a simple fixed-threshold starting rule, in which a full stream is initiated by using a fixed threshold. A control window is introduced to regulate the degree of service merging. Experimental results show that proposed online recursive patching schemes outperform the traditional graceful patching scheme by a wide margin even with a very small client buffer size. A moderate buffer size (i.e. 5 - 10 min) is large enough to maintain a good performance for proposed schemes.