The following figure shows the virtual machine resources required to support all 25,000 users. There are four virtualized mailbox servers per DAG, as well as four corresponding CASs and three ETSs at each data center. In addition, there is one file share witness virtual machine per DAG and Active Directory Domain Controller virtual machines, which are required for the Microsoft Exchange infrastructure and also to provide Global Catalog services.

 

The following figure shows the physical hosts and resources required to support the Microsoft Exchange infrastructure. In this configuration, a number of dedicated physical hosts are employed at the on-premises data center to host the Microsoft Exchange virtual machines, the Active Directory Global Catalog virtual machines, the file share witness, and to provide sufficient resources for vSphere HA admission control reserved capacity. The hardware resources employed at the VMware Cloud Provider facility are provided by a dedicated VMware vCloud Director® Organizational Virtual Data Center (VDC).

 

In the figure, the first DAG has been configured with an active database on ms-ex-mb1 and a local passive database copy on ms-ex-mb2 at the customer’s on-premises data center. A secondary passive database on ms-ex-mb5 has been configured at the VMware Cloud Provider facility for high availability and disaster recovery purposes. This architecture provides redundancy in multiple failure scenarios at both the on-premises and provider data centers.