Hypervisor migrations? Complete DC migrations? If you are doing that every single quarter you are doing something VERY wrong (or you should migrate to the cloud).
You don't have to do these migrations, but you should be able to do them because basic security maintenance of systems require regular patching, reboots, downtimes, etc. Setting up a new VM and deploy the apps/services takes minutes, not days.
The infra has to be setup to support downtime of systems (not all at once obviously).
The infra has to be setup to support downtime of systems (not all at once obviously).