File Share Witness Not Configured

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2007-03-23

Microsoft Exchange Server 2007 setup cannot continue because a file share witness has not been configured for the cluster continuous replication (CCR) cluster.

To sustain the failure of any one node in a Majority Node Set (MNS) quorum cluster, you must have at least three devices that can be considered as available. The file share witness feature enables you to use an external file share as a witness. This witness acts as the third available device in a two-node MNS quorum cluster.

Exchange 2007 setup requires that the file share witness feature be configured for installation of the clustered Mailbox server role in a CCR environment.

To address this issue, follow the procedure to create and secure the file share for the file share witness as shown in "How to Configure the File Share Witness" ( Then set the MNSFileShare value, move the cluster group two times, and try Microsoft Exchange setup again.