Exchange Server 2007 Business Continuity
Microsoft Exchange Server 2007 provides out-of-the-box high availability, clustering, and disaster recovery capabilities. A new feature called Continuous Replication makes it easy to add database redundancy to an Exchange environment, so that recoveries can be made in minutes, even between geographically separate sites.
Continuous Replication uses log shipping to replicate changes from an active Exchange database to a passive copy. This database copy can be placed on a local disk drive, on a separate server, or in a remote datacenter. With Continuous Replication, the time required to recover from storage, server, and site-level failures is dramatically reduced because a database copy is available for immediate activation.
Three types of Continuous Replication provide organizations with the right level of redundancy for their business needs:
| Local Continuous Replication is a basic configuration in which the active database and its copy are both attached to the same server. If the active database experiences storage failure or data corruption, the administrator can switch to the copy in minutes instead of spending hours restoring a backup. |
| Cluster Continuous Replication combines log shipping with the failover and management features provided by the Microsoft Windows Cluster service. Active/Passive server pairs provide complete redundancy of mailbox services and data, enabling automatic recovery from failures. |
| Standby Continuous Replication, a new feature delivered in Exchange Server 2007 Service Pack 1, enables mailbox data to be replicated to a standby server. The standby server can be placed in an off-site location, providing a disaster recovery solution that is resilient to the failure of an entire datacenter. |
Traditional Exchange clustering, which relies on a single, shared copy of mailbox data, is still available in Exchange Server 2007. Cluster Continuous Replication has the advantage of not requiring shared storage, which makes it easier to deploy site-resilient solutions, and allows the use of less-expensive storage technologies, including Direct Attached Storage.
To summarize, Continuous Replication has these benefits:
Built-in Exchange Server solution: Continuous Replication is part of the Exchange Server product. It is a native solution optimized for Exchange Server and managed using a familiar set of tools.
Reduces backup requirements: Continuous Replication reduces dependence on traditional backups. With a “hot” copy of each database, tape backups become a safety net, rather than a primary means of recovery, and so the frequency of backups can often be reduced.
Enables large, low-cost mailboxes: Continuous Replication allows organizations to expand mailbox quotas without sacrificing recovery capabilities. Administrators can give users larger mailboxes without worrying that long recovery times will jeopardize their ability to fulfill Service Level Agreements.
Drives down cost of high availability: CCR does not require expensive shared-storage, so it is less expensive than traditional Exchange clustering, and LCR allows organizations to increase their uptime simply by adding an disk drives to a server.
See how Microsoft has saved millions on tape backup requirements by deploying Exchange Server 2007 Continuous Replication.
