Overview of DFS Replication
Published: October 22, 2009
Updated: October 16, 2013
Applies To: Windows Server 2008 R2, Windows Server 2012, Windows Server 2012 R2
DFS Replication is an efficient, multiple-master replication engine that you can use to keep folders synchronized between servers across limited bandwidth network connections. It replaces the File Replication Service (FRS) as the replication engine for DFS Namespaces, as well as for replicating the Active Directory Domain Services (AD DS) SYSVOL folder in domains that use the Windows Server 2008 domain functional level. For more information about replicating SYSVOL using DFS Replication, see the Microsoft Web site (http://go.microsoft.com/fwlink/?LinkId=139749).
DFS Replication uses a compression algorithm known as remote differential compression (RDC). RDC detects changes to the data in a file and enables DFS Replication to replicate only the changed file blocks instead of the entire file.
To use DFS Replication, you must create replication groups and add replicated folders to the groups. Replication groups, replicated folders, and members are illustrated in the following figure.
This figure shows that a replication group is a set of servers, known as members , which participates in the replication of one or more replicated folders. A replicated folder is a folder that stays synchronized on each member. In the figure, there are two replicated folders: Projects and Proposals. As the data changes in each replicated folder, the changes are replicated across connections between the members of the replication group. The connections between all members form the replication topology.
Creating multiple replicated folders in a single replication group simplifies the process of deploying replicated folders because the topology, schedule, and bandwidth throttling for the replication group are applied to each replicated folder. To deploy additional replicated folders, you can use Dfsradmin.exe or follow the instructions in a wizard to define the local path and permissions for the new replicated folder.
Each replicated folder has unique settings, such as file and subfolder filters, so that you can filter out different files and subfolders for each replicated folder.
The replicated folders stored on each member can be located on different volumes in the member, and the replicated folders do not need to be shared folders or part of a namespace. However, the DFS Management snap-in makes it easy to share replicated folders and optionally publish them in an existing namespace.
You can administer DFS Replication by using DFS Management, the
Dfsrdiag commands, or scripts that call WMI.