I have not done this, and have only used DNS on Windows NT, but since no one
else was biting.

Windows NT stores DNS information in the registry as well as a directory...
\winnt\system32\dns\.  I think that there is a way to have it store the
information only in file, not the registry and possibly vice versa.  Backing
up this directory is not a problem.  The problem is getting Windows to use
it when you restore it.  If you simply lose the directory or want to go back
to a previous version of DNS information you can probably stop DNS, restore
the file and start DNS again.  Disaster recovery of the NT system is another
matter.  If you don't have a bare-bones restore option for the system, you
may need to reinstall Windows, TSM, and DNS.  When DNS is installed, and the
DNS files (\winnt\system32\dns\) restored Windows will not read them.  You
need to go into DNS and recreate each zone.  When it asks for the name of
the new zone file, use the name of the one that you restored (the DNS files
should be restored at this time).  Windows will then create the zone with
all of the entries that were in the restored file.

There is probably an easier way to do this, but I haven't looked hard enough
to find it.  A lot of this is testing that you can do with NT/2000 without
TSM.

Hope this helped a bit

Scott Foley
NetVoyage Corp
sfoley AT netdocuments DOT com