What is the use of DFS That is added as a new Feature in windows server 2008 ?

DFS offers simplified, highly available access to files, load sharing, and WAN-friendly replication. In the Windows Server® 2008 R2 operating system, Microsoft has added a number of features and improvements to existing features.

Following are the changes are available on DFS Namespaces in Windows Server 2008 R2:

• DFS Management support for enabling access-based enumeration
• Performance counters
• Performance improvements for large namespaces
• DFS Management support to selectively enable namespace root referrals
• Improved Dfsdiag.exe command prompt Help text

The following changes to DFS Replication are available in Windows Server 2008 R2:

• Failover cluster support
• Read-only replicated folders
• Read-only domain controllers have read-only SYSVOL folders
• Additional DFS Replication diagnostic functionality in the Dfsrdiag.exe command-line too

Here is an article for complete understanding of what DFS is, and how to implement in your organization.

http://blogs.technet.com/b/josebda/archive/2009/03/10/the-basics-of-the-windows-server-2008-distributed-file-system-dfs.aspx

DFS Replication is an easy and effective way to replicate data between servers. When changes are detected in a file, only the blocks that change are replicated. Consequently, DFS Replication works efficiently overlow bandwith connections. This makes DFS Replication an excellent option for, among other uses,replicating data from remote locations to a central office.

Distributed File System (DFS) Namespaces and DFS Replication offer simplified, highly available access to files, load sharing, and WAN-friendly replication. In the Windows Server® 2008 R2 operating system, Microsoft has added a number of features and improvements to existing features.

The following changes to DFS Namespaces are available in Windows Server 2008 R2:

• DFS Management support for enabling access-based enumeration
• Performance counters
• Performance improvements for large namespaces
• DFS Management support to selectively enable namespace root referrals
• Improved Dfsdiag.exe command prompt Help text

The following changes to DFS Replication are available in Windows Server 2008 R2:

• Failover cluster support
• Read-only replicated folders
• Read-only domain controllers have read-only SYSVOL folders
• Additional DFS Replication diagnostic functionality in the Dfsrdiag.exe command-line tool
• What new functionality does DFS Namespaces provide?  

  The following changes are available in Windows Server 2008 R2 for DFS Namespaces:

  • DFS Management support for enabling access-based enumeration
  • Performance counters 
  • Performance improvements for large namespaces
  • DFS Management support to selectively enable namespace root referrals
  • Improved Dfsdiag.exe command prompt Help text
  DFS Management support for enabling access-based enumeration  

  Access-based enumeration displays only the files and folders that a user has permissions to access. If a user does not have Read (or equivalent) permissions for a folder, Windows hides the folder from the user's view. For example, if you enable access-based enumeration on a shared folder that contains many users' home directories, users who access the shared folder can see only their personal home directories; other users' folders are hidden from view.

  You can enable access-based enumeration in two complementary locations:

  • When you enable access-based enumeration on a shared folder by using Share and Storage Management, Windows displays folders and files in the NTFS file system to network users only if they have Read (or equivalent) permissions to the folders and files. 
  • When you enable access-based enumeration on a namespace by using DFS Management (or the Dfsutil command, which is also supported in Windows Server 2008), Windows displays folders in the namespace to network users only if the namespace administrator has given them Read permissions to the DFS folders.