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Disaster recovery with database copies and DAGs
17 Dell EMC PowerVault ME4 Series and Microsoft Exchange Server 2016 | 3925-BP-EX
6 Disaster recovery with database copies and DAGs
In the event of a hardware or software failure, multiple database copies in a DAG enable high availability with
fast failover and no data loss. This eliminates end-user downtime and lost productivity that make up a
significant cost of recovering from a past point-in-time backup to disk or tape. DAGs can be extended to
multiple sites and can provide resilience against data-center failures as well.
While all Mailbox servers in a DAG must be in the same Active Directory domain, up to 16 copies of an
Exchange Server 2016 mailbox database can be created on multiple Mailbox servers, provided the servers
are grouped into a DAG. However, the round-trip network latency must not be greater than 250 milliseconds.
ME4 Series storage can provide excellent scale and performance, which enables additional ME4 Series
arrays to host DAG copies and local or remote locations to aid in data recovery.