What does DAG stand for in the context of Exchange Server?

In the context of Microsoft Exchange Server, DAG stands for Database Availability Group. This is a critical feature within Exchange Server that allows for high availability and disaster recovery of mailbox databases. A Database Availability Group is a group of up to 16 Exchange server mailbox members, and it enables redundancy and failover capabilities without needing to use a shared storage solution.

The primary function of a DAG is to allow automatic recovery of mailbox databases. If a database or server goes down, the system can automatically switch operations to another healthy database or server within the group. This ensures that users experience minimal disruption and maintains business continuity.

DAGs also include features such as Data Redundancy and Continuous Replication, which means that any changes made to the mailbox database are continuously replicated to passive copies on other servers within the group. This approach greatly enhances data resilience and general operational reliability within an Exchange environment. Understanding the role and function of a Database Availability Group is essential for maintaining Exchange server availability and performance.