Somewhat related: I have a branch of Ganeti that has first-class ZFS support baked in, including using ZFS snapshot replication to do live migration without shared storage or CEPH: https://github.com/linsomniac/ganeti
Current status is I'm looking for more feedback. In a few weeks when Ubuntu 26.04 comes out I'm going to set up my dev/stg clusters at work with it, at the moment I've only tested it in a test cluster at home.
It works this way: It creates a snapshot of the zvol, and replicates it to the secondary machine. When that's done, it does another snapshot and does a "catch up" replication (the first replication could take hours on large volumes). Pause the VM, do a final snapshot+replication. Replicate the working RAM. Start up the VM on the new host.