File-sharing applications remain today the most representative and popular realization of the Peerto-Peer paradigm. Large objects receive an increasing amount of interest in such systems. In this paper, we identify several challenges related to sharing voluminous content such as movies, OS distributions, games, etc, in unstructured Peer-to-Peer networks. We then describe our scheme which adaptively expands or contracts system resources in order to improve the sharing process and achieve a fair load distribution among the providers.