We have 5 servers (Exchange 2016 ) in DAG right now along with 4 domain controllers. I do not have much experience in backup and restore process of Exchange and Actve Directory server. I have following question and would like to understand under what circumstances, what restore option I would need to use.
1: As I have mentioned above that 5 Exchange servers are part of DAG and Mailbox databses are replicated on other nodes. Each server have separate drives for Exchange mailbox database besides system C drive.
If one servers gets corrupted or goes down due to any reason like after aplying Windows Updates so what should I need to do?
a: should I need to restore only system state and keeping the other drives ( mailbox database and logs) same as it ?
b: What is Bare Metal recovery and in what scenarios I would have to do Bare Metal Recovery of Exchange?
2: The Exchange Environment have four domain controllers and all domain controllers have GC and DNS role. So If one domain controller gets corrupted. Should I need to recover the whole system from backup? If yes, then I restore the one domain controller from previous state. Then will it sync with other domain controllers?