How to Configure Witness Server in Exchange 2016 & 2013

Hello guys today we are going to discuss about how to configure witness server in exchange 2016 or 2013. In this article we will learn brief about witness server too. So Lets proceed..

Configure Witness Server in Exchange 2016

What is Witness Server?

As you might know that the witness server is used for high availability and site resilience in a Database Availability Group (DAG). It helps exchange server for managing user requests in a DAG among nodes of two different Exchange servers. In a big organization, Exchange server is installed in a DAG for good manageability and high availability.

Importance of Witness Server

If you are going to install at least two different datacenters then you must configure one witness server. Lets discuss about importance of witness server in more detail.
Suppose there are ten exchange server nodes are installed in a DAG. In which five nodes are installed on datacenter 1 and five other nodes are installed on datacenter 2. datacenter 1 is the primary where all databases are active at datacenter 2 there are mirror image of site 1 database.
Lets assume that the connection between datacenter 1 and datacenter 2 is not available cause of an issue. Issue could be any disaster or anything else. The fault percentage will be 50 % because the half nodes are not online and the server will disconnect all mailboxes and like this Site A will also be unavailable.
But when File Share Witness (FSW) will be available in datacenter 1 then FSW will also be considered as an another node. And if there is no connection available between both sites then the site which have more number of nodes are Online will be available. In disconnected case datacenter 1 will have six nodes including FSW and datacenter 2 will have five nodes. Therefore all mailboxes of datacenter 2 will be disconnected.
Witness server is useful when there are even number of exchange servers are installed in a DAG. According to above defined scenario witness server provides failover clustering and help to remain at least one datacenter active at any cost.

Preconfiguration for Witness Server Installation

Before going to install and configure Witness Server in Exchange 2016 DAG, first go through the windows firewall setting and check whether your computer is connected to the domain or not. If already connected then all is okay other wise you have to connect your computer to domain first.
Now go to Add Roles and Features Wizard to install one server role. Therefore select File Server under File and Storage Services and complete the installation process.
After Installation of file server role add Exchange Trusted Subsystems Group to local Administrator. You just need to go to computer management and then in left panel expand Local Users and Groups and then click on groups. Now in result pane at middle select Administrators and add new group of Exchange Trusted Subsystems.
Configure Witness Server in Exchange 2016

Configure Witness Server in Exchange 2016

To create and configure new witness server in Exchange 2016 or 2013 there must be a shared folder related to it. Therefore first create a shared folder. Just go to C drive and create a folder (in my case folder name is abc). Then go to properties and make it shared.
After creation of shared folder, go through Exchange Admin Center (EAC) then click on Servers and then click on database availability groups. Now click on + sign and enter new Database Availability Group Name, Witness Server and Enter the location of Shared folder which you have created.


In this article we have discussed about how to configure witness server in exchange 2016. We have also discussed about what is witness server? and the Importance and usage of witness server.

Tej Pratap Shukla