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DFS Namespaces and DFS Replication Overview
Published: May 9, 2012
Updated: February 20, 2013
Applies To: Windows Server 2012
This topic discusses the DFS Namespaces (DFSN or DFS-N) and DFS Replication (DFSR or DFS-R) role services, which together comprise Distributed File System (DFS) in Windows Server 2012. This topic discusses how to install DFS, what’s new, and where to find evaluation and deployment information.
Did you mean…
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DFS Management (online Help from Windows Server 2008 R2)
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File and Storage Services Overview
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File Services Windows Server Protocols
DFS Namespaces and DFS Replication in Windows Server 2012 are role services in the File and Storage Services role.
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DFS Namespaces Enables you to group shared folders that are located on different servers into one or more logically structured namespaces. Each namespace appears to users as a single shared folder with a series of subfolders. However, the underlying structure of the namespace can consist of numerous file shares that are located on different servers and in multiple sites.
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DFS Replication Enables you to efficiently replicate folders (including those referred to by a DFS namespace path) across multiple servers and sites. DFS Replication uses a compression algorithm known as remote differential compression (RDC). RDC detects changes to the data in a file, and it enables DFS Replication to replicate only the changed file blocks instead of the entire file.
You can use DFS Namespaces and DFS Replication to achieve the following goals:
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DFS Namespaces Provide users with a centralized folder namespace through which to access and store files. You can host the underlying file shares on different servers and in different sites to improve availability and performance.
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DFS Replication Synchronize folder contents efficiently between servers, across LAN or WAN network connections.
 Note |
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| DFS Replication can also be used to replicate the SYSVOL folder in Active Directory Domain Services (AD DS) in domains that use the Windows Server 2012, Windows Server 2008 R2, or Windows Server 2008 domain functional levels. |
The following table describes the changes in DFS Namespaces and DFS Replication functionality that are available in this release.
| Feature/functionality | New or updated? | Description |
|---|---|---|
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New |
Provides Windows PowerShell cmdlets for performing the majority of administration tasks for DFS Namespaces. |
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New |
Provides remote client computers with optimal referrals to corporate resources when the computers connect by using DirectAccess to the corporate network. |
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New |
Provides the latest Windows Management Infrastructure-based management methods to manage DFS Namespaces. |
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New |
Provides support for replicated folders stored on volumes that use Data Deduplication. |
Windows Server 2012 includes Windows PowerShell cmdlets for performing the majority of administration tasks for DFS Namespaces.
What value does this change add?
Administrators can use the extensive Windows PowerShell cmdlets to perform common administration tasks, and optionally automate them by using Windows PowerShell scripts.
What works differently?
Instead of using DFS Management or DFS command-line utilities, administrators can perform all common tasks by using the Windows PowerShell cmdlets.
The Windows PowerShell cmdlets are available on computers that run Windows Server 2012 or Windows 8 and that have the DFS Management Tools feature (part of the Remote Server Administration Tools) installed.
For more information, see DFS Namespace (DFSN) Cmdlets in Windows PowerShell and Introducing DFS Namespaces Windows PowerShell Cmdlets.
 Tip |
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| To use the Windows PowerShell module for DFS Namespaces from a computer that does not have the module installed, use the Enter-PSSession cmdlet to establish a session with a computer that has the DFS Management Tools feature installed. |
Windows Server 2012 includes site awareness for DirectAccess functionality to provide optimal site-aware referrals to remote users who access a corporate network by using DirectAccess.
What value does this change add?
Remote users who connect to DFS namespaces over a DirectAccess connection receive referrals to the namespace servers and folder targets that are closest to their location. This reduces network latency when accessing files on the corporate network, making more efficient use of bandwidth.
What works differently?
When accessing a DFS namespace path by using DirectAccess in Windows 7 or Windows Server 2008 R2, remote computers that have IP addresses outside of the sites specified in Active Directory Domain Services receive a randomly ordered referral that could include servers in distant sites, even when servers in a nearby site are available.
When a remote computer accesses a DFS namespace path by using DirectAccess on computers running Windows 8 or Windows Server 2012, the computer provides a site name in the referral request to the namespace server running Windows Server 2012. The namespace server uses the site name to provide a referral to the closest site available.
For site awareness to work for clients that are using DirectAccess, the client computer must be running Windows 8 or Windows Server 2012 and the server must be running Windows Server 2012.
Windows Server 2012 includes new Windows Management Infrastructure (the new version of WMI) provider functionality, which provides programmatic access to manage DFS Namespaces.
What value does this change add?
Management programs can use the latest Windows Management Infrastructure-based methods to manage DFS Namespaces.
What works differently?
Windows Management Infrastructure-based management access occurs over a firewall-friendly Windows Remote Management (WinRM) transport protocol.
Windows Server 2012 includes support for replicated folders stored on volumes on which Data Deduplication is enabled.
What value does this change add?
You can use the new Data Deduplication functionality to reduce storage requirements without impacting DFS Replication.
What works differently?
DFS Replication replicates the new reparse point tag IO_REPARSE_TAG_DEDUP.
The following features are included in Windows Server 2012, but they are being phased out, and they likely will be removed from future versions of the Windows Server operating system.
| Deprecated feature | Replacement |
|---|---|
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DFS Namespaces command-line tool, Dfscmd |
DFS Namespaces module for Windows PowerShell |
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File Replication Service (FRS) |
DFS Replication |
For a complete list of deprecated features in Windows Server 2012, see Features Removed or Deprecated in Windows Server 2012.
For more information about FRS support in Windows Server 2012 and Windows Server 2008 R2, see File Replication Service (FRS) Is Deprecated in Windows Server 2008 R2.
There are no additional hardware or software requirements for running DFS Management or using DFS Namespaces, except for the newly added features described previously, which require Windows Server 2012 (or in some cases Windows 8).
Before you can deploy DFS Replication, you must configure your servers as follows:
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Update the Active Directory Domain Services (AD DS) schema to include Windows Server 2012, Windows Server 2008 R2, Windows Server 2008, or Windows Server 2003 R2 schema additions. (If you install a domain controller running Windows Server 2012 the schema is automatically updated.) You cannot use read-only replicated folders with the Windows Server 2003 R2 or older schema additions.
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Ensure that all servers in a replication group are located in the same forest. You cannot enable replication across servers in different forests.
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Install DFS Replication on all servers that will act as members of a replication group.
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Contact your antivirus software vendor to check that your antivirus software is compatible with DFS Replication.
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Locate any folders that you want to replicate on volumes formatted with the NTFS file system. DFS Replication does not support the Resilient File System (ReFS) or the FAT file system. DFS Replication also does not support replicating content stored on Cluster Shared Volumes.
DFS Namespaces and DFS Replication are a part of the File and Storage Services role. The management tools for DFS (DFS Management, the DFS Namespaces module for Windows PowerShell, and command-line tools) are installed separately as part of the Remote Server Administration Tools.
To install the role services and the DFS Management Tools, use one of the following methods.
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Open Server Manager, click Manage, and then click Add Roles and Features. The Add Roles and Features Wizard appears.
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On the Server Selection page, select the server or virtual hard disk (VHD) of an offline virtual machine on which you want to install DFS.
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Select the role services and features that you want to install.
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To install the DFS Namespaces and DFS Replication services, on the Server Roles page, select DFS Namespaces and DFS Replication.
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To install only the DFS Management Tools, on the Features page, expand Remote Server Administration Tools, Role Administration Tools, expand File Services Tools, and then select DFS Management Tools.
DFS Management Tools installs the DFS Management snap-in, the DFS Namespaces module for Windows PowerShell, and command-line tools, but it does not install any DFS services on the server.
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To install the DFS Namespaces and DFS Replication services, on the Server Roles page, select DFS Namespaces and DFS Replication.
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Open a Windows PowerShell session with elevated user rights, and then type the following command, where <name> is the role service or feature that you want to install (see the following table for a list of relevant role service or feature names):
Install-WindowsFeature <name>
Role service or feature Name DFS Namespaces
FS-DFS-NamespaceDFS Replication
FS-DFS-ReplicationDFS Management Tools
RSAT-DFS-Mgmt-ConFor example, to install the Distributed File System Tools portion of the Remote Server Administration Tools feature, type:
Install-WindowsFeature RSAT-DFS-Mgmt-Con
To install the DFS Namespaces, DFS Replication, and the Distributed File System Tools portions of the Remote Server Administration Tools feature, type:
Install-WindowsFeature FS-DFS-Namespace, FS-DFS-Replication, RSAT-DFS-Mgmt-Con
For additional related information, see the following resources.
