We report on a bulk object-loading algorithm for persistent object stores called Ghosted Allocation. It allocates large numbers of objects in a persistent store atomically, efficiently, and reliably. Its main strengths are that it minimizes I/O traffic, optimizes the disk access pattern, and does not impose complex requirements on applications. Our experiments demonstrate that the Ghosted Allocation algorithm is efficient and most importantly scalable, sustaining allocation rates of up to 63 000 objects s-1. Copyright © 2001 John Wiley & Sons, Ltd.