Change the File Share Witness on Exchange Server

Change the File Share Witness on Exchange Server

The requirements for the witness server are as follows:


    • 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.



  • We recommend that you use an Exchange 2013 Client Access server in the Active Directory site containing the DAG. This allows the witness server and directory to remain under the control of an Exchange administrator. Regardless of what server is used as the witness server, if the Windows Firewall is enabled on the intended witness server, you must enable the Windows Firewall exception for File and Printer Sharing.


  • If the witness server you specify isn't an Exchange 2013 server, you must add the Exchange Trusted Subsystem universal security group to the local Administrators group on the witness server prior to creating the DAG. These security permissions are necessary to ensure that Exchange can create a directory and share on the witness server as needed.


Command to change FSW


Set-DatabaseAvailabilitygroup -Identity <DAGNAME> -WitnessDirectory <C:\FSW_DIR_DAG1> -WitnessServer <Server FQDN>



You can use the below method to verify the status of File share witness on windows server 2008 R2


Method 1.

  • Using Failover Cluster Manager connect to the cluster service.  You can connect to either a node or specify the DAG name as the connection point.
  • Click on the cluster name in the upper left hand corner of the utility.
  • In the center window information is displayed regarding the cluster configuration.
  • One piece of information is the “Quorum Configuration”.  This will list the type of quorum in use and if a file share witness is configured the server and share name utilized as the witness.




Method 2:


  • open cmd prompt and run cluster res



Comments (6)

  1. Qayoum says:

    Good one Karthik

  2. Qayoum says:

    Best one Karthik.

  3. Bekir says:

    Why Windows Server 2012 (and R2) is not in the supported server list?


    1. Thanks Bekir for pointing out. I will get the post updated

  4. MohammedShahabuddin says:

    Any impact on DAG while changing FSW. Any downtime required. Please cofirm.

    1. No Impact during the change if all your nodes are up.

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