DFS Terminology

DFS namespace

A DFS namespace is a collection of DFS shared folders. It uses the same UNC pathname structure, except instead of \\ServerName\FileShareName with DFS, it is \\domainname with all DFS shared folders located under this DFS root. For example, instead of:

\\FS-1\Engineering

\\FS-2\Accounting

\\FS-3\Documents

You can have:

\\Contoso.com\Engineering

\\Contoso.com\Accounting

\\Contoso.com\Documents

In this scenario, the Engineering, Accounting, and Documents folders can all be hosted on separate file servers and you can use a single namespace to locate those shared folders, instead of needing to know the identity of the file server that hosts them.

DFS Terminology

A number of technical terms are used when referring to deploying, configuring, and referencing DFS. The DFS namespace and DFSR have already been described, but the remaining terms should also be understood before reading the remainder of this chapter or deploying a new DFS infrastructure:

Image DFS namespace—A unified namespace that presents a centralized view of shared folder data in an organization.

Image DFS namespace server—A Windows server that hosts a DFS namespace.

Image DFS namespace root—The top level of the DFS tree that defines the namespace for DFS and the functionality available. The namespace root is also the name of the DFS namespace. A domain-based root adds fault-tolerant capabilities to DFS by allowing several servers to host the same DFS namespace root.

Image DFS folder—A folder that is presented under the root when a DFS client connects. When a root is created, folders can be created within the file system, but DFS folders allow the system to redirect clients to different systems other than the namespace server hosting the root.

Image Folder target—A share hosted on a Windows server. The DFS folder name and the share name do not need to be the same, but for troubleshooting purposes, it is highly recommended. Multiple folder targets can be assigned to a single DFS folder to provide fault tolerance. If a single folder target is unavailable, clients will be connected to another available target. When DFS folders are created with multiple folder targets, replication can also be configured using DFSR groups to keep the data across the targets in sync. Folder targets can be a share name or a folder beneath a share. For example, \\server1\userdata or \\server1\userdata\Finance are both valid folder targets.

Image DFS tree—The hierarchy of the namespace. For example, the DFS tree begins with the DFS root namespace and contains all the defined folders below the root.

Image Referrals—A configuration setting of a DFS namespace/folder that defines how DFS clients connect to the namespace server, a folder in the namespace, or a particular folder target server. Referral properties include limiting client connections to servers in the local Active Directory site and how often to check the availability of a DFS server. Disabling a target’s referral keeps it from being used by clients. Target referral can be disabled when maintenance is performed on a server.