How to Rebuilt Global Catalog?

I am running two domain controllers in a windows 2003 r2 infrastructure. The main domain controller with the global catalog role went down and I had to reformat it. Now I am facing issues with creating new users in the active directory. I think I must create a global catalog but how? or is it possible since the original domain controller is not there anymore?

Thanks in advance

Solution 1:

The Global Catalog is a sub-set of the domain itself (and includes any Universal groups in the forest, if it is in one), so a GC can be regenerated from a simple DC. Creating a global catalog is done in the Active Directory Sites and Services tool. This Microsoft article describes it in some detail:

http://support.microsoft.com/kb/313994

Quoting:

To create a new global catalog:

1. On the domain controller where you want the new global catalog, start the Active Directory Sites and Services snap-in. To start the snap-in, click Start, point to Programs, point to Administrative Tools, and then click Active Directory Sites and Services.
2. In the console tree, double-click Sites, and then double-click sitename.
3. Double-click Servers, click your domain controller, right-click NTDS Settings, and then click Properties.
4. On the General tab, click to select the Global catalog check box to assign the role of global catalog to this server.
5. Restart the domain controller.

Solution 2:

I would also advise using NTDSUTIL to clean out any remnants of the old DC, which otherwise will be lingering and may mess with your setup.