Over the weekend, good friend, Mitch Garvis decided it was necessary to rebuild his
home network. Now, most home networks don’t have a $25,000 Server at the core.
This one did. Given that, we decided to do it right. The network
architecture called for Virtualization, so we decided to use Hyper-V. The network
called for management, so we decided to install SCCM and Ops Manager. The network
called for simplicity so we used Active Directory.
However, we decided to up the ante and install this all on Server Core. Now,
the tricky part is that we needed to install Active Directory. The reason this
became tricky was because there is no documented procedure out there on how to install
a new Forest on Core. There are lots of very smart people on the internet that
described how to install new domains part of existing forests, but not new forests.
So we got to work.
After running dcpromo a few times we realized we couldn’t create the Forest by throwing
commands at it. It occurred to one of us that we should try creating an unattend.txt
install file. After a few tries, we figured out the proper structure of the
file, and after 10 minutes of watching the CLI spit out random sentences, we had a
new domain.
The structure of the file is fairly simple, but you need the correct variable data.
We used the following unattend.txt file to create the new domain:
[DCInstall]
InstallDNS=yes
NewDomain=forest
NewDomainDNSName=swmi.ca
DomainNetBiosName=SWMI
SiteName=Default-First-Site-Name
ReplicaOrNewDomain=domain
ForestLevel=3
DomainLevel=3
DatabasePath="%systemroot%\ntds"
LogPath="%systemroot%\ntds"
RebootOnCompletion=yes
SYSVOLPath="%systemroot%\sysvol"
SafeModeAdminPassword=Pa$$w0rd
Now: Once the file was created we put it in the root of C: on the server core machine,
and typed the following command:
dcpromo /unattend:c:\unattend.txt
Surprisingly it worked. After checking with Microsoft, this is a supported option,
and it’s not a hack in any way. It’s just undocumented.
Until now.
Reference: Mitch Garvis, SWMI, http://garvis.ca/blogs/mitch/archive/2009/10/12/creating-a-new-domain-forest-on-server-core.aspx
