Which server should be the Exchange 2013 DAG Witness Server

dagdomain-controllerexchange-2013

Imagine a standard setup with an Active Directory Server, 4 Exchange servers ( 2 with CAS roles, and two with Mailbox roles) with load balancing and failover.

This site talking about how putting the witness on the Domain Controller is bad practice.

Question:

(If that is actually true) Then where should it go and why? (Knowing fully well that it should not be on a CAS or MB server)

Quote:

Section on the site mentioning this, and they go into depth as to why it's not good practice.

Obligatory disclaimer: While this is definitely not recommended
practise in a production environment, and may have undesirable
results, it will probably work. I highly doubt Microsoft support this,
though I have been unable to find any concrete evidence on it
(frankly, it’s such terrible practise they shouldn’t have to publicise
advice against it).

Best Answer

We typically use Exchange HUB as a File Share Witness server. Here are MS's recommendations

The witness server can't be a member of the DAG.
The witness server must be in the same Active Directory forest as the DAG.
The witness server must be running Windows Server 2012, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003 R2, or Windows Server 2003.
A single server can serve as a witness for multiple DAGs. However, each DAG requires its own witness directory.

Source: Managing database availability groups
https://technet.microsoft.com/en-us/library/dd298065%28v=exchg.150%29.aspx
Applies to: Exchange Server 2013

EDIT: My mistake, the reference on using the Hub for FSW was from 2007/2010 rather than 2013. Exchange 2013 made an architectural change to exchange roles

Related Topic