The economies of scale realised by institutional and commercial cloud providers make such resources increasingly attractive for grid computing. We describe an implementation of this approach which has been deployed for Australia’s ATLAS and Belle II grid sites. The sites are built entirely with virtual machines (VM) orchestrated by an Open- Stack instance. The storage element (SE) utilises an XRootD-S3 gateway with back-end storage provided through an S3-compatible object store from a commercial provider. The prov…