No software is capable of doing live migration/high availability for pet type containers and virtual machines except lxd.

But nspawn isn’t really a management software like lxd is, it’s more of a container runtime like lxc is.

Ninja edit: Did some googling and I’m technically wrong. Hashicorp’s nomad supports lxc as a driver, but according to the doc it only supports host networking…

https://developer.hashicorp.com/nomad/plugins/drivers/community/lxc#networking

But nomad also supports managing nspawn containers which is interesting.