Active directory backup / restore question

I am trying to do a Symantec backup exec solution for domain controllers. The production environment which we have is composed of 2 AD domain controllers running on Windows 2008 OS. Both the servers are global catalogs and one of them is FSMO roles holder, as shown below:
SERVER1 - GC / DNS / FSMO roles holder
SERVER2 - GC / DNS / DHCP SERVER

My question is, if the Server2 crashes, should I restore whole system from the backup or should I just install new server with identical name/ip address, and include it into domain and dcpromo it and import DHCP database and authorize it on the AD level to start serving clients? If Server1 crashes then I think that I dont have other solution but restore the system from backup, is that right? Thanks.

It is recognized that the Active Directory Domain Services (ADDS) - one of the apparatus of mandatory infrastructure used for the functioning of Windows. If Active Directory be unsuccessful, the network, for the majority part, it turns out to be useless. For that reason, planning a backup and restore Active Directory is an assurance of security. Within Windows Server 2008 has a lot of latest functions associated to Active Directory, two of which are straightforwardly associated to planning backup and recovery: Utility Data Archiving Windows Server »and the capability to make use of snapshots of Active Directory, made using VSS.