DNS on Windows Server 2003, 3rd Edition

Where Is All This Information Stored?

You may be wondering what’s happened to all the resource records we’ve been entering. Where are they being stored? The answer is: in the memory of the DNS server process. We mentioned earlier that the DNS console communicates with the DNS server using an RPC mechanism. As you add records to a zone with the DNS console, they are added “on the fly” to the name server’s memory. Of course, the name server’s memory is transient—when the name server process stops, its memory is lost. Obviously it needs a permanent storage location, too.

This is where the zone datafiles specified when we created the zones come in. The zone datafiles are the zones’ permanent storage location, holding all the zones’ resource records. If you use the DNS console to make a change to a zone, the copy of the zone in the name server’s memory is changed, and a flag is set to update that zone’s datafile. The name server updates the zone datafile when it exits, unless you tell it to update the file sooner. Choosing Action → Update Server Data Files (available when a name server is selected in the left pane) causes the name server to update the zone datafiles of all the zones for which it’s a primary (if the version of a zone in the server’s memory is more recent than the version on disk). There’s also a per-zone version of this command: with a primary zone selected in the left pane, selecting Action → Update Server Data File causes the server to update only that zone’s file. ...