You create a domain to organize a hierarchy of groups, users, clients, and policies in your organization. For example, you may want to add domains to organize users by division.
You can use a domain ID for disaster recovery. If all the management servers in your organization fail, you need to rebuild the management server by using the same ID as the old server. You can get the old domain ID from the sylink.xml file on any client.
To add a domain
In the console, click Admin.
On the Admin page, click Domains.
Under Tasks, click Add Domain.
In the Add Domain dialog box, type a domain name, an optional company name, and optional contact information.
If you want to add a domain ID, click Advanced and then type the value in the text box.
See About domains.