Windows 2000's Distributed File System

Distributed File System (Dfs) is a Windows 2000 feature that lets you group shared folders from different servers into one logical namespace, making it easy for users to locate and access shared folders on your network. Let's suppose that your network has eight file servers that users access daily. Without Dfs, the users must remember the name of each server and the shares that each server hosts. Alternatively, those users must map multiple drives. With Dfs, you can create a Dfs root on one of these eight file servers, which becomes the Dfs root server, with links to the shares on each of the other file servers. To a user accessing the Dfs root, the shares appear to reside on the machine that's hosting the Dfs root. In reality, each link transparently redirects requests to a share on one of the multiple file servers. As you can see, Dfs can solve some of the share-distribution problems that result from storage limitations, poor planning, and additional file servers that you add to the network—without a major redistribution project.

Dfs Roots
Win2K Dfs lets you create two kinds of Dfs roots: standalone and domain-based. With a standalone Dfs root, you risk creating one point of failure on your network. If the server that hosts the Dfs namespace goes down, so does users' ability to access distributed shares through the namespace—even if the servers that host the shared resources are still available. Domain-based Dfs roots solve this problem by letting you specify additional servers, called root replicas, to host copies of the Dfs, providing fault tolerance and a degree of load balancing. In addition, through the use of Active Directory (AD) sites, a client that attempts to connect to a Dfs root server will attempt to contact one located at its same site to reduce network traffic.

In addition to root replicas, you can create links within the Dfs tree that refer clients to multiple copies of a shared folder. As with the root replicas, this feature provides fault tolerance and a degree of load balancing, and it takes advantage of your site topology to control network traffic at the share level. You can also configure Win2K’s File Replication Service (FRS) to synchronize copies of shares when you make changes to the files they contain.

Setting Up Dfs
Now that you understand Dfs and the advantages of domain-based Dfs roots, you should find creating Dfs roots to be straightforward. As with most administrative tasks in Win2K, you can turn to a Microsoft Management Console (MMC) snap-in to help you create and manage Dfs. Start the MMC by clicking Start, Run, and typing mmc. From the console menu, choose Add/Remove Snap-in, Add, and choose Distributed File System from the list of available snap-ins. To create a new Dfs root, right-click the Dfs icon and choose New Dfs Root, which launches a wizard that prompts you for the kind of Dfs root that you want to create (standalone or domain-based), the host domain, the host server, and the Dfs root share. The Dfs root share is the name that users will use to connect to the Dfs root to navigate the hierarchical namespace that you create as you start establishing links. The only file that you want to keep in this folder is perhaps a readme file containing information about the links in the namespace and the resources they reference. After you create the Dfs root, you can right-click it to begin creating your Dfs links or, if you're working with a domain-based Dfs, your root replicas.

Accessing the Dfs Root
Accessing a Dfs root is similar to accessing any network share. From Start, Run, type \domain_nameDfs_root _name or, for a domain Dfs root, \server_nameDfs_root_name. For a standalone Dfs root, type \server_nameDfs_root_name. Users can locate Dfs roots by navigating through My Network, just as they do to access other shares on the network.