[Samba] Advices about migrate W2000 domain to SAMBA4

[Ivan Lopez]

Hi, People:

We have a Old (well functioning) Windows 2000 AD domain. We wish migrate 
DCs, if posible, to SAMBA4.  We actually have four sites with one DC in 
three of them and three DCs in one of them. Just one DC is Windows 2008, 
the rest is Windows 2000.

Join SAMBA4 as DC automatically is not posible, I think, because DNS 
servers are not configured with 2008 behaviour and actual DNS entries 
does not replicate to SAMBA. Therefore, I can't replace Windows DCs.

Is there any method/howto to achieve this with minimum disruption?. Or 
the only way is upgrade DCs to Windows 2008 (paying new licenses) and 
then join SAMBA4 DCs to domain, transfer roles an demote Windows DCs?

Thanks in advance!

Iván