# Installing Server 2012 R2 in a Server 2003 R2 environment



## joswoody (Oct 5, 2011)

I have a domain which has 2 Domain Controllers of Windows Server 2003 R2.

We need to update the DC + AD from windows server 2003 r2 to Windows Server 2012 R2.

I was thinking of installing a DC with Windows Server 2012 R2, making the Forest Functional Levels as: Windows Server 2003
Then I will replicate the Active Directory and DNS from the old server to the new one.

After, I was thinking of either migrating from Server 2003 to Server 2012 R2 or else decommissioning the 2003 DC and re creating the server.

1) Do you think that this is possible? If yes, is there something that I have to keep in mind or take precautions about it?

2) What do you think is best, updating the old server or re-creating it?

Thanks,
Joseph


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## Triple6 (Dec 26, 2002)

So you don't want to move all the roles at once? Is that the question? Also what do you mean by re-creating the server? I wouldn't keep a 2003 server around, migrate the roles to the 2012 server and decommission the old one. Server 2012 will upgrade your domain for you and move the roles.

Here's how: http://blogs.technet.com/b/canitpro...ndows-server-2003-to-windows-server-2012.aspx
Or here: http://community.spiceworks.com/how...-directory-from-server-2003-to-server-2012-r2


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## joswoody (Oct 5, 2011)

Thanks for your reply.

Another problem is that I have DHCP server installed on this server. What do you suggest it is best you do? All IPs on the subnet are taken and are all on the DHCP server which is on the DC. Does Windows 2003 R2 support split scope as I was thinking that for a alternative?

Thanks.


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## Triple6 (Dec 26, 2002)

It does, so now you plan on keeping the 2003 server for DHCP?

How many computers devices do you have on this network? What is your current DHCP pool?


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## joswoody (Oct 5, 2011)

No my plan is that the DHCP server will be on the new Server. My question is how I am going to move the DHCP Server to the new one without any downtime possible?

Thanks.


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## Triple6 (Dec 26, 2002)

https://technet.microsoft.com/en-ca/library/cc772306.aspx

Or

https://technet.microsoft.com/en-ca/library/dn495425.aspx


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## joswoody (Oct 5, 2011)

Thanks for your reply.

Another thing...I need to do this without downtime, if possible.

The machines are having their settings by a reservation in the DHCP Server?

Will they still keep their settings during the migration when there will be no dhcp server available?

Thanks.


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## Triple6 (Dec 26, 2002)

You can un-authorize one DHCP and authorize the other server pretty quick and computers that already have addresses will keep those. You can have DNS running on both servers with IP's of both servers so regardless which one is doing DHCP or which one is running DNS it'll will still work. Just read the articles and follow the steps if you have a complicated DHCP setup with lots of reservations and export the database settings.

Personally I do such things in off-hours whenever I can.


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## joswoody (Oct 5, 2011)

Thanks mate!


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