[Aldipower]

Assuming you can afford 2 machines this setup works pretty well for me.

Primary DB-Server -> XFS on LVM with a LVM caching SSD

Secondary (write-only) mirror DB-Server -> ZFS

The DB is replicating automatically to the secondary server by the database internal replication features. At the secondary I am then able to lock the DB temporarily, doing a ZFS snapshot and maybe could do a ZFS send/receive afterwards without affecting the primary server.

ZFS is great for doing snapshots and archiving of huge amount of data, but it's very very bad for production databases in terms of performance. Most database aren't designed to deal with the CoW feature of ZFS, which leads to a very bad write performance and database fragmentation in the end.