  Worldwide, storage demands and costs are increasing. As a consequence of
fault tolerance, storage device heterogenity, and data center specific
constraints, optimal storage capacity utilization cannot be achieved with the
integrated balancing algorithm of the distributed storage cluster system Ceph.
This work presents Equilibrium, a device utilization size-aware shard balancing
algorithm. With extensive experiments we demonstrate that our proposed
algorithm balances near optimally on real-world clusters with strong available
storage capacity improvements while reducing the amount of needed data
movement.
