Comment by vbernat

Restarting a whole datacenter from scratch is different from restarting individual servers. If a service needs another service running on another server, it may fail to start. For example, many servers may need the DHCP server. Some servers may need the DNS. Some others may need Kafka to be up and running, etc. You may have some documentation on which servers to start first, but things are moving so fast that it's not unlikely you'll need to rely on supervision to know which service was able to start correctly.