Ad-hoc filesystems for dynamic science workloads

<!--HTML-->In this talk, we present recent work supporting the computing demands of the Euclid space mission using resources from across an OpenStack federation for scientific computing. CephFS is used to present a single coherent filesystem drawing upon resources from multiple sites. We present our approach and experiences. We then present an alternative approach to filesystems on-the-fly using the Data Accelerator project at Cambridge University, currently #1 in the global IO-500 list. We provide an overview of the technologies involved and an analysis of how its high performance levels are achieved.