That is a common question among Exchange administrators, what happens if I have an issue during the Exchange Deployment? Well, I created a scenario where the domain controller is turned off during the process to show how the Exchange setup behave.
In this Tutorial we are going to test how the resume setup of Exchange Server 2013 works. In order to test it properly during the Exchange Server 2013 setup process we will be turning off the domain controller, and as we know the Active Directory is the foundation for Exchange Server.
Read more at source: http://itprocentral.com/how-does-it-work-the-exchange-server-2013-setup-resume-process/