Azure File Sync: Integration with DFS Namespaces



Hello everyone, this is Andrew Coughlin and I am a Customer Engineer at Microsoft focusing on Azure IaaS. In this blog I will focus on a couple of questions I get quite often around Azure File Sync, does Azure File Sync support DFS-N, how do you set DFS-N with Azure File Sync and can I have two Azure File Sync servers in a DFS-N target folder. 

Azure File Sync is a service that allows you to turn your on-premises servers into caching servers.  All files in the directory you specify for Azure File Sync will be copied to a file share in a account.  You can also enable a feature called Cloud Tiering, with this feature you can set which files stay on premises and which ones are in the cloud only.  To the end user this feature is seamless, and they don't know if their file is on the file server or in the cloud.   For more information about Azure File Sync head over to the planning for an Azure File Sync deployment page.


  • Share the folders out on each server(s)
  • Create DFS Namespace as documented here.

Does Azure File Sync Support DFS-N

One of the most common questions I receive is can you use Azure File Sync with Distributed File System Namespaces (DFS-N).  A lot of corporate customers use DFS-N to hide the backend file server.  This allows them to change the backend server without having impact to their end users. Azure File Sync does support DFS-N, from an interoperability it also supports Distributed File System (DFS-R) for those customers looking to migrate away from DFS-R to Azure File Sync. Let's see how we can add a share on an Azure File Sync server to DFS-N.

Add Share under Azure File Sync to DFS-N

First, we will want to launch the DFS Management tool and connect to the name space if the name space doesn't show up.  Then we will right click on the name space and click “New Folder”.


Next you will provide the folder name and click Add.


Then click Browse, type the Azure File Sync server, if needed, and select the folder and click OK.


Click OK, on the Add Folder Target window.


Click on OK, on the New Folder window.


Add Additional / New Azure File Sync Server to a Folder Target

There are a couple of reasons why you might want to add a second server to a folder target that has a share syncing with Azure File Sync:

  • Two servers in different locations part of the same sync group
  • DR purposes
  • Retiring an older Azure File Sync server

NOTE: At the time of writing this article global locking is not supported for Azure File Sync or Azure Files.

To add an additional server to a target folder in DFS-N with Azure File Sync.  First open DFS Management, find the folder you are wanting to add to the target folder and right click it and go to Add Folder Target.


Click Browse, Type the second file server, and click Show Shared Folders.  You will then select the shared folder and Click OK.


Click OK, on New Folder Target window.


You will receive a message.  This message is asking you if you want to setup a group.  With two servers' part of the same sync group we are using Azure File Sync to keep both servers synchronized.  You will click No because of this.

NOTE: DFS-R and Azure File Sync can co-exist, the use case for this is for migrating from DFS-R to Azure Files, for more information about this migration process please see this link.



In this blog I covered supportability with Azure File Sync with DFS-N, add a server with Azure File Sync to DFS-N and add an additional server to a target folder in a DFS Namespace.  Thank you for taking the time to read this blog, I hope this helps you and see you next time.


This article was originally published by Microsoft's SQL Server Blog. You can find the original article here.