Question : Migration of active directory from x32  server to x64 server

Question:
We need to know, how we can migrate active directory from x32 platform DC server to x64 platform DC server. We would like to ask you about compatibility and pross and cons of this solution. Thanks for quick answer in advance.

Answer : Migration of active directory from x32  server to x64 server

32 Bit and 64 bit DCs talk to each other with no issues so you can have both on your domain. If you want to migrate your DCs to 64 bit then just add the 64bit machine as an additional DC and then move the FSMO roles etc in exactly the same way as you would if replacing a 32bit DC with another 32bit DC

in detail:

Install Windows 2003 on the new machine
Assign the new computer an IP address and subnet mask on the existing network
Make sure that the preferred DNS server on new machine points to the existing DNS Server on the Domain (normally the existing domain controller)

Join the new machine to the existing domain as a member server

If the new Windows 2003 server is the ‘R2’ version and the existing set-up is not then you need to run Adprep  from CD2 of the R2 disks on the existing Domain controller. Adprep is in the \CMPNENTS\R2\ folder on CD2 (if this is necessary you may need to get a 32bit version on Adprep to run on the existing machines - you can use an evaluation version)

From the command line promote the new machine to a domain controller with the DCPROMO command from the command line
Select ‘Additional Domain Controller in an existing Domain’

Once Active Directory is installed then to make the new machine a global catalog server, go to Administrative Tools, Active Directory Sites and Services, Expand ,Sites, Default first site and Servers. Right click on the new server and select properties and tick the ‘Global Catalog’ checkbox. (Global catalog is essential for logon as it needs to be queried to establish Universal Group Membership)

Assuming that you were using Active Directory Integrated DNS on the first Domain Controller, DNS will have replicated to the new domain controller along with Active Directory.

If you are using DHCP you should spread this across the domain controllers, In a simple single domain this is easiest done by Setting up DHCP on the second Domain controller and using a scope on the same network that does not overlap with the existing scope on the other Domain Controller. Don’t forget to set the default gateway (router) and DNS Servers. Talking of which all the clients (and the domain controllers themselves) need to have their Preferred DNS server set to one domain controller, and the Alternate DNS to the other, that way if one of the DNS Servers fails, the clients will automatically use the other,

Both Domain Controllers by this point will have Active Directory, Global Catalog, DNS and DHCP. and the domain could function for a while at least should any one of them fail.

Before removing the 32bit machine:-
Transfer all the FSMO roles: See http://www.petri.co.il/transferring_fsmo_roles.htm

Make the other DC a global catalog: Go to Administrative Tools, Active Directory Sites and Services, Expand ,Sites, Default first site and Servers. Right click on the new server and select properties and tick the ‘Global Catalog’ checkbox. (Global catalog is essential for logon as it needs to be queried to establish Universal Group Membership)

If the DC is running DHCP:
Install DHCP on the new DC, set up the scope and authorise it. remove DHCP from the old DC.

DNS: Make sure that all of your clients are set to use the new DC as their Preferred DNS server (either by static entries or DHCP options)

Power down to old DC and make sure that all is well, once satisfied power on the old DC again, then run DCPROMO for remove it's domain controller status. If you want to remove the machine from the domain then you can do so one it's DC role has been removed