Hyper-V Replication versus Exchange DAG

Rupert Eghardt
Rupert Eghardt used Ask the Experts™
Hi Guys,

I would like to setup replication and recovery for an Exchange 2016 server running on VM (Hyper-V).

The two options I am currently investigating is setting up
1.  Hyper-V Replication to another site (VM), or
2.  MS Exchange DAG to another site

Has anyone perhaps explored or setup both options, and which works the best as a long term solution?
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Exchange does not support the  VM replication, so the best option would be to have the DA extended to different site
Technical Architect - HA/Compute/Storage
Running a DAG provides failover capabilities thus things can be set up for mail to keep flowing in the event of a failure.

Hyper-V Replica only supports a maximum frequency of 15 seconds. For a busy mail server setup the replication volume may be higher than a typical WAN can handle. This is a recipe for data loss.

A small two node Storage Spaces Direct cluster could be set up to provide resilience against hardware failure. Besides Exchange, a DC, and other workloads could be run on it. I suggest looking into this as an option.
AmitIT Architect
Distinguished Expert 2017

Answer to your question is:
2.  MS Exchange DAG to another site
Lee W, MVPTechnology and Business Process Advisor
Most Valuable Expert 2013

Products that include their own DR functionality / replication capabilities are not supported for Hyper-V replica.  This includes Exchange (because of DAGs), Active Directory (DCs; because this is a multi-master model to begin with), and SQL server (because of SQL replication).  While you CAN replicate with Hyper-V Replica, it can result in data loss as Hyper-V replica's best replication frequency is 15 seconds as Philip states.  Generally, I would only do this in small environments and explain the pitfalls of doing so (the potential for data loss).  Hyper-V replica is better than nothing especially in low budget environments that cannot afford the additional hardware and software licenses to do it properly.  But again, understand the potential for data loss.

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