Hi @Андрей Михалевский,
Welcome to the Microsoft Q&A platform!
You are right that the File Share Witness (FSW) is not used when there is an odd number of servers in a Database Availability Group (DAG). In this case, the quorum model is "Node Majority", which means that FSW is not required. This is why the folder is not created.
To ensure that everything is working properly, you can perform the following checks:
- Run the command
Get-ClusterQuorum
in PowerShell to check the quorum configuration. It should indicate “Node Majority.” - Use the command
Get-DatabaseAvailabilityGroup -Identity ms-dag01 -Status | Format-List
to review the status of the DAG and ensure all nodes are healthy. - Run the cluster validation tool to ensure that there are no potential issues. You can do this from the Failover Cluster Manager by selecting "Validate Configuration".
- Check the event logs on the file server and the Exchange server for any errors or warnings related to the DAG or cluster.
- Ensure that the Exchange Trusted Subsystem has the necessary permissions on the file server, even if FSW is not used in this configuration.
If you encounter any specific errors or warnings during these checks, feel free to share them and I can help you troubleshoot further.
Please feel free to contact me for any updates. And if this helps, don't forget to mark it as an answer.
Best,
Jake Zhang