Review the following requirements for installing Exchange Server 2007 on the secondary site:
Before you begin installation, make sure to take the Exchange cluster group offline on the primary site; otherwise, the installation on the secondary site will not function properly.
On the secondary site nodes, do not install the Active Clustered Mailbox role. Instead, install the Passive Clustered Mailbox role on all nodes of the secondary site.
Make sure that the same drive letter and path are available on all nodes and have adequate space for the installation. For example, if you install the Exchange program files in C:\Program Files\ExchSrvr
on one node, you must install the files in C:\Program Files\ExchSrvr
on all the other nodes. Use a drive letter on the local disk of each node in the cluster.
Refer to the Microsoft documentation for additional prerequisites and details on Exchange installation.