Distributed file system (Dfs)

Dfs, or Distributed file system, is a separately available add-on for the Microsoft Windows NT operating system and a component of the Windows 2000 operating system.

What is Dfs (Distributed file system)?

A separately available add-on for the Microsoft Windows NT operating system and a component of the Windows 2000 operating system. The Distributed file system (Dfs) allows file servers and network shares to be logically organized into a single Dfs directory tree. This simplifies management of network resources and makes it easier for users to locate and access network resources.

From the user’s perspective, the Dfs makes it appear that there is only one server containing a hierarchical tree of resources, while in fact these resources might be distributed across multiple servers in different locations.

The Dfs simplifies directory browsing, offers search tools that simplify locating network resources, and offers administrative tools for building and managing Dfs directory trees. It also eliminates the need for Windows 95, Windows 98, or Windows NT Workstation clients to form multiple persistent network connections, because users require only one persistent connection to the directory tree.

How it works

In the Windows 2000 implementation, you first open the Dfs snap-in for Microsoft Management Console (MMC) to create a Dfs root node. You can then create Dfs child nodes under the root node. Each child represents a shared folder that can be located anywhere on the network. When users want to access a resource on the network, they navigate through the Dfs tree and do not need to know the particular server the resource is located on. Users must have Dfs client software installed on their machines. Dfs client software is included with Windows 2000, Windows NT, and Windows 98. An optional Dfs client can be downloaded for Windows 95 from the Microsoft Web site.

You can configure Dfs to operate in two ways:

  • Stand-alone Dfs stores the description of the Dfs file system topology on a single computer. If that computer fails, the entire Dfs system goes down, although users can still access resources the traditional way using mapped network drives or Universal Naming Convention (UNC) paths if they know which servers these resources are stored on and the names of the shares.
  • Fault tolerant Dfs stores the Dfs topology information in Active Directory on Windows 2000 domain controllers. This configuration is better for fault tolerance and file replication.

If a server containing Dfs shares fails, you can simply move the files to another machine, create new shares, and map the existing Dfs child nodes to the new shares. Your users won’t even know that anything has changed. If you assign a user permission to access a shared folder, that person automatically has permission to access it through the Dfs tree as well.