Microsoft® Exchange Server 2010: Best Practices

Planning Cross-site Failovers

The high-availability improvements in Exchange 2010 make it even easier to deploy cross-site failover solutions without a need for third-party network and storage solutions. The secondary site can be used to handle primary site outages resulting from maintenance or other, more serious failures. Even with the improvements in Exchange 2010, careful planning must be done to successfully deploy and maintain a multi-site deployment.

Cross-site DAG Considerations

The primary building block of a cross-site solution is the cross-site DAG. Extending a DAG between sites does have a couple requirements, including the following:

• Fewer than 250 milliseconds of latency between all DAG members. To ensure consistent DAG operations there ...