Browse Definitions :
Definition

database availability group (DAG)

Contributor(s): Matt Gervais

A database availability group (DAG) is a high availability (HA) and data recovery feature of Exchange Server 2010. 

A database availability group, which can consist of up to 16 Exchange mailbox servers, automates recovery at the database-level after a database, server or network failure. 

Database availability groups replaced Exchange Server 2007’s high-availability model, which was based on local continuous replication (LCR), standby continuous replication (SCR), single copy clustering (SCC) and cluster continuous replication (CCR).

Exchange administrators can choose to use DAGs in different geographic locations and in many different architectural designs and configurations, making it considerably more flexible than previous high-availability setups.

NTFAQGuy explains how high availability features have evolved from Exchange Server 2003 through Exchange Server 2010 and at 4 minutes in, explains how Exchange database availability groups work.

This was last updated in July 2012

Continue Reading About database availability group (DAG)

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • compliance audit

    A compliance audit is a comprehensive review of an organization's adherence to regulatory guidelines.

  • regulatory compliance

    Regulatory compliance is an organization's adherence to laws, regulations, guidelines and specifications relevant to its business...

  • Whistleblower Protection Act

    The Whistleblower Protection Act of 1989 is a law that protects federal government employees in the United States from ...

SearchSecurity

  • payload (computing)

    In computing, a payload is the carrying capacity of a packet or other transmission data unit. The term has its roots in the ...

  • passphrase

    A passphrase is a string of characters longer than the usual password (which is typically from four to 16 characters long) that ...

  • Web application firewall (WAF)

    A Web application firewall (WAF) is a firewall that monitors, filters or blocks traffic to and from a Web application. WAFs are ...

SearchHealthIT

SearchDisasterRecovery

SearchStorage

  • computational storage

    Computational storage is defined as an architecture that couples compute with storage in order to reduce data movement. In doing ...

  • data deduplication

    Data deduplication -- often called intelligent compression or single-instance storage -- is a process that eliminates redundant ...

  • public cloud storage

    Public cloud storage, also called storage-as-a-service or online storage is a service model that provides data storage on a ...

Close