Applies to: Exchange Server 2007 SP3, Exchange Server
2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2007-09-12
Cluster continuous replication (CCR) in Microsoft Exchange Server 2007 provides several advantages over clustering in previous versions of Exchange Server and single copy clustering in Exchange 2007:
- No single point of failure CCR creates
a clustered solution that uses a model of active and passive pairs.
This model means that all key functionality or data has an active
instance and one passive (backup) instance.
- No requirement for shared
storage Storage in a CCR environment is not
shared between the nodes in the failover cluster. This makes setup
easier because storage does not need to be configured prior to
forming the cluster. You can select between direct attached
storage, storage area network (SAN), iSCSI, or other supported
storage. For more information about supported storage solutions,
- Microsoft-provided solution that allows a single mailbox
server to span two datacenters The cluster
features in previous versions of Exchange Server required a
third-party replication solution to enable site resiliency. In
Exchange 2007, site resiliency is provided in the product.
- No specialized cluster validation required for hardware
configuration Because CCR does not require
shared storage, it is not necessary to select hardware from the
Cluster category or Geographically Dispersed Cluster category in
the Microsoft Windows Server Catalog. The only requirement is
that the servers are listed as standalone servers in the Windows
- Improved failover
behavior Exchange 2007 failover behaviors
take advantage of two completely independent copies of the log and
database data. This design improves the overall recovery behavior
and reduces the likelihood of recovery operations being blocked by
the same failure.
- Simplified installation The
Exchange 2007 installation experience has improved over
previous releases. The clustered mailbox server installation has
been unified with the stand-alone mailbox server installation. As a
result, administrators have an experience that is consistent across
both environments. Because there is no requirement for shared
storage, installation is further simplified.
- Improved management experience The
management experience has been improved by hiding cluster-specific
administration under associated Mailbox server operations. For
example, storage group configuration within Exchange does all the
necessary updates to the high availability infrastructure used to
manage the cluster. The management experience is also improved
because there is no requirement for shared storage.
- Ability of offload backup workload CCR
creates a second copy of databases on a passive node. The passive
node can be used to offload the effect of doing regular backups.
For example, by doing backups on the passive node, the backup
window can be extended and the I/O load is no longer on the active
node. Backups are supported for both production and copy storage
groups and databases using an Exchange-aware Volume Shadow Copy
Service (VSS)-based solution, such as Microsoft System Center Data
Protection Manager 2007. Streaming backups are only supported from
the active node. Exchange-aware restores to the active copy can
either be done using streaming or VSS backup solutions.
For More Information
For more information about Microsoft System Center Data Protection Manager 2007, visit http://www.microsoft.com/dpm.