Welcome to the Community,
in addition to what weinstein5 already said, ensure you shut down the VM's in a proper order. If e.g. the DC's are virtual machines you may want to shut them down after all other VM's have been shut down and as a last step shut down the ESXi host on which the DC's were running.
Basically the same (just the other way around) applies, when you power the environment back on.
André