Create DAG (Database Availability Group) in Exchange 2016

Well, Creating DAG is much more simpler as comparing to Exchange 2010,But configuring it properly is the best part to have it efficiently working.

So lets see how to create a 2 node DAG , where most of the Environments are willing to have 2 Dedicated servers for Exchange Server 2016 – (No Roles Anymore – All in One)

Preferred Architecture –

• Usage of Hardware Load balancers.
• Combining all Roles in Same Server.
• No Need of Dedicate Replication Network with highly Available 10g Interfaces.
• No Need of DAG IP and it shouldn’t have any Administrative Access Point.
• Usage of Third Witness site to create Active/Active Datacenter (If third site not available keep Witness in Primary Site).

I will describe my environment now.

I have 3 AD sites ,Primary Site And DR-Site has Exchange Servers have a Third Site for Witness.

Get-ExchangeServer | FT name,site -AutoSize

Network Configuration –
I will have my Primary LAN which are Highly Available 10g interfaces which is more sufficient to handle client/replication traffic.

NOTE : If you have 10g Interfaces which is highly Available. Dedicated Replication Network has become optional.Preferred Architecture states to have only one network.

Not Required to pre stage a Cluster CNO object anymore.

• Now DAG runs without a Cluster Administrative Access Point.

If your DAG Witness Server is not an Exchange Server add Exchange Trusted Subsystem in Local Administrators group

Start – Run – lusrmgr.msc

Now we will  Create a DAG ,

Login to EAC –Servers – Database Availability Groups – Choose New

Specify –

* DAG name

* Witness Server Name

* Witness Location

Now my DAG Configuration is Ready
Add members to it.

Choose Manage DAG Membership

Add your DAG members –

if your Volumes are ReFS – Creating ReFs Volumes for Exchange 2013/2016

To check Default DatabaseAvailabilityGroup FileSystem Type –

Get-DatabaseAvailabilityGroup | FT Name,FileSystem -AutoSize

Change DatabaseAvailabilityGroup FileSystem Type to ReFS –

Set-DatabaseAvailabilityGroup DAG2016 –FileSystem ReFS

To Prevent against application-level split brain syndrome – Enable Datacenter Activation Coordination mode (DAC) –

To check Default DatabaseAvailabilityGroup DatacenterActivationMode Type –

Get-DatabaseAvailabilityGroup | FT Name,DatacenterActivationMode –AutoSize

Change DatabaseAvailabilityGroup DatacenterActivationMode Type to DagOnly –

Set-DatabaseAvailabilityGroup -Identity DAG2016 -DatacenterActivationMode DagOnly

Great !! Now your DAG is ready with Recommended Configuration ! you can start adding Database Copies !!