[magicalhippo]

There was some work done to add a S3 storage backend for ZFS[1], precisely with the goal of running PosgreSQL on effectively external storage.

A key point was to effectively treat S3 as a huge, reliable disk with 10MB "sectors". So the bucket would contain tons of 10MB chunks and ZFS would let S3 handle the redundancy. For performance it was coupled with a large, local SSD-based write-back cache.

Sadly it seems the company behind this figured it needed to keep this closed-source in order to get ROI[2].

[1]: https://youtu.be/opW9KhjOQ3Q

[2]: https://github.com/openzfs/zfs/issues/12119

[ddorian43]

Neon does this for PostgreSQL and it's open source (more like code-dump though)