[Feature] Migrating of QEMU machines

[lfarnell]

Currently, Nomad does not handle QEMU allocation migration properly. According to @diptanu

Yeah we simply shutdown the process. So no we don't shutdown the VM properly.

My use case specifically would be a Windows VMs and migrating those allocations between nodes. If I'm running a SQL Server database or IIS web server as an example, I wouldn't the VM process to just be killed and restarted on another node. I would almost prefer some form of "live migration" across hosts. The reason for this specifically is because most Windows software doesn't handle shutdowns very well or at all so just rapidly killing the process could have adverse effects. Another scenario would be when issuing a node-drain on a host.

[cheeseprocedure]

Hi @lfarnell! Just a heads-up: my team ran into this requirement as well, and we added a graceful shutdown option for the QEMU driver here (it uses the QEMU monitor under the hood): #3411

It's certainly not live migration, but it gives VMs the opportunity to shut down properly.