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
* DAG name
* Witness Server Name
* Witness Location
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 !!