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Your network consists of one Active Directory forest that contains one root domain and 22 child domains.
All domain controllers run Windows Server 2003.
All domain controllers run the DNS Server service and host Active Directory-integrated zones. Administrators report that it takes more than one hour to restart the DNS servers.
You need to reduce the time it takes to restart the DNS servers.
What should you do?
A. Upgrade all domain controllers to Windows Server 2008.
B. Upgrade all domain controllers in the root domain to Windows Server 2008, and then set the functional level for the root domain to Windows Server 2008.
C. Deploy new secondary zones on additional servers in each child domain.
D. Change the Active Directory-integrated DNS zones to standard primary zones.
Correct Answer: A
Explanation/Reference:
Very large organizations with extremely large zones that store their DNS data in AD DS sometimes discover that restarting a DNS server can take an hour or more while the DNS data is retrieved from the directory service. The result is that the DNS server is effectively unavailable to service client requests for the entire time that it takes to load AD DS-based zones.
A DNS server running Windows Server 2008 now loads zone data from AD DS in the background while it restarts so that it can respond to requests for data from other zones. When the DNS server starts, it:
Enumerates all zones to be loaded.
Loads root hints from files or AD DS storage.
Loads all file-backed zones, that is, zones that are stored in files rather than in AD DS. Begins responding to queries and remote procedure calls (RPCs).
Spawns one or more threads to load the zones that are stored in AD DS.
Because the task of loading zones is performed by separate threads, the DNS server is able to respond to queries while zone loading is in progress. If a DNS client requests data for a host in a zone that has already been loaded, the DNS server responds with the data (or, if appropriate, a negative response) as expected. If the request is for a node that has not yet been loaded into memory, the DNS server reads the node’s data from AD DS and updates the node’s record list accordingly.
http://technet.microsoft.com/en-us/library/cc753635%28v=ws.10%29.aspx
