如果计算节点重新启动或停止工作会发生什么？

I wonder what is happening when a machine that runs computation node with active VMs is shutdown due hardware malfunction or power outage. After some time restarting and returns back? Does OpenStack somehow manage "to move" VMs that were configured to that node to run on another node? What happened to networking between VMs on other nodes trying to reach VMs that were running on the shutdown node?I wonder what is happening when a machine that