Applies to: Exchange Server 2007
Historical: Local Continuous Replication (LCR) was an Exchange Server 2007 high-availability feature. It was removed in Exchange Server 2010 and replaced by the Database Availability Group (DAG) and mailbox database copy model.
LCR creates a second copy of an Exchange 2007 storage group on the same Mailbox server. Transaction logs are copied and replayed into the replica database, providing a local recovery copy if the active database or storage fails.
In This Article
- 1. What LCR Does
- 2. Configure Local Continuous Replication
- 3. Important Storage Considerations
- 4. What Replaced LCR
- 5. Key Takeaways
1. What LCR Does
LCR is a single-server replication technology. It is enabled per storage group and uses Exchange log shipping to maintain a passive local copy of the databases in that storage group.
The replica is not another Exchange server. If the active database or storage fails, an administrator must activate the local copy manually.
2. Configure Local Continuous Replication
- Sign in to the Exchange Server 2007 Mailbox server.
- Open Exchange Management Console.
- Go to Server Configuration > Mailbox.
- Select the Mailbox server.
- Select the storage group that you want to protect.
- In the Actions pane, select Enable Local Continuous Replication.
- Choose separate locations for the local replica system files and transaction logs.
- Specify the replica database path for each mailbox database in the storage group.
- Review the configuration and select Enable.
3. Important Storage Considerations
LCR protects against storage failure only when the replica is placed on storage that is independent from the active copy. Microsoft recommended separating the active and passive storage as much as possible, including separate arrays and storage controllers where practical.
Keeping both copies on the same physical storage removes much of the protection that LCR was designed to provide.
4. What Replaced LCR
Exchange Server 2010 removed LCR, Cluster Continuous Replication (CCR), and storage groups. High availability moved to Database Availability Groups and mailbox database copies, which replicate databases between Exchange servers instead of maintaining an LCR copy on the same server.
5. Key Takeaways
- LCR applies only to Exchange Server 2007.
- It maintains a local passive copy by shipping and replaying transaction logs.
- The replica should use storage independent from the active copy.
- Activation of the LCR copy is an administrative recovery action.
- Exchange 2010 and later use DAGs and mailbox database copies instead of LCR.
References
- Microsoft Exchange Team Blog – Exchange Server 2007 High Availability Storage Considerations
- Microsoft Learn – Circular Logging and Exchange 2007 LCR/CCR
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