In this paper, Dept. of Computer Science, University of Waterloo Waterloo, Ontario, Canada, N2L 3G1 we consider how to exploit multiple disks to improve the performance of B-tree structured files. Attention is paid both to the response time of individual operations and to the throughput of the system in a multi-user environment. We begin with a survey of three different approaches to designing multi-disk B-trees: distributing records among disks, using large multi-disk pages, and distributing pages among disks. For each approach, several alternatives are discussed and their main advantages and disadvantages are identified. We then propose a new scheme, based on page distribution, that is intended to provide a better local balancing of the request load than previous schemes. Preliminary performance results confirm that this irrproves both response time and throughput.