Depends what you are after. For public access, something like webDAV is probably the lowest hanging fruit. However its still HTTP based, so not great for spee

Depends what you are after. For public access, something like webDAV is probably the lowest hanging fruit. However its still HTTP based, so not great for speed or partial writes. HDFS is not worth the hassle, same goes for ceph, its a lot of work for slower worse performance than ZFS/pNFS. If you want speed and posix, then something like GPFS from IBM is where to go, failing that, lustre, which you can get from AWS if you want to try it.