I've been using SeaweedFS at home for the past 18 months or so as an S3 alternative, and it seems to be a great alternative to Ceph at smaller scales. I've had a hard time getting Ceph to scale down far enough to really be stable with a small number of nodes. Even with ~7 nodes, I had issues for years with Ceph getting into rebalancing storms and taking itself down. I'm sure they've fixed some of the issues, but it's fundamentally a heavy-weight system.

SeaweedFS just kinda works. You can add nodes and disk on the fly trivially, and I haven't had any issues saturating 2x10G links with reads from it.