If you install Exchange 2000 in Active/Active cluster scenarios, there are multiple Exchange virtual servers that have to be created. As part of creating the first Exchange virtual server, administrators can select the administrative group that this virtual server will be a member of. This option is available (if there is already more than one administrative group in the organization) when the Microsoft Exchange system attendant resource is created.
For more information, see the C20_clustering.rtf file in the DOCS directory of the Exchange 2000 installation CD-ROM.
When Exchange virtual servers are created after the first one, there are not any administrative groups to select from that these virtual servers are members of. This is because all virtual servers on Exchange 2000 cluster have to be members of the same administrative group.
For general information about how to install Exchange 2000 on clustered nodes, see the white paper at the following Microsoft Web site: