I am not the op nor an expert on this, but I think https://ceph.io/ targets clusters of this scale.
We build clusters of low PB scale that have a TCO with everything from labor to hardware, from financing to electric, from routers to cables and can be run below 3€/TB. For that you can store data in Block(rbd, iscsi), Objekt(S3, swift) or Filestorage(CephFS, NFS, SMB), high available on Supermicro hardware in any datacenter worldwide.
Feel free to contact us or use our free community edition to start your own cluster.