Yeah, that is exactly what we were doing. We used ZFS to do replication of the docker-in-LXC services between servers. I guess we need to rebuild that in qemu now, but docker-in-lxc on ZFS, even with AUFS was just super easy in terms of configuration, maintenance, replication. It even enabled a pretty useful sort-of-HA, because */15 replication only takes 3 seconds and LXC startup time is 5-10 seconds.the only situation I know of where that one could be used, is when using docker in CTs on ZFS.