The DFS FAQ may be of use to you. In particular, the section called
DFS Availablity near the bottom on the page.
Here is a snippet from the FAQ.
Q. How do I ensure the availability of a DFS namespace?
A. The answer depends on type of namespace: stand-alone or
For stand-alone DFS namespaces, you ensure the availability of a
stand-alone DFS root by creating it on the cluster storage of a
clustered file server by using the Cluster Administrator snap-in.
For domain-based DFS namespaces, you ensure the availability of
domain-based DFS roots by creating multiple root targets on
nonclustered file servers or on the local storage of the nodes of
server clusters. (Domain-based DFS roots cannot be created on cluster
storage.) All root targets must belong to the same domain. To create
root targets, use the Distributed File System snap-in or the
Dfsutil.exe command-line tool.
To ensure the availability of domain-based DFS roots, you must have at
least two domain controllers and two root targets within the domain
that is hosting the root. If you have only one domain controller and
it becomes unavailable, the namespace is inaccessible. Similarly, if
you have only a single root target, and the server hosting the root
target is unavailable, the namespace is also unavailable.
Note that DFS (Namespaces) is often used in conjunction with some form
of file replication (usually FRS or DFS Replication that is new in R2,
but it can even be robocopy). When you have multiple link targets
that have files replicated between them, you can have DFS fail over to
an alternate target when one link target becomes unavailble. Here is
another snippet from the FAQ.
Q. How do I increase the availability of data in link targets?
A. There are two ways to increase the availability of data in link
Create a single link that points to a link target on a clustered
Create multiple link targets and replicate content among them.
You can create link targets that point to clustered file servers in
both types of namespaces. However, if you want to replicate content
among multiple link targets, the type of namespace determines your
Using Replication in Stand-alone DFS Namespaces
In a stand-alone DFS namespace, you can replicate the files by copying
them manually, using scripts, using Robocopy.exe, which is available
in the Microsoft Windows Server 2003 Deployment Kit, or by using other
replication tools. The Distributed File System snap-in does not
provide a user interface for configuring FRS replication in
stand-alone DFS namespaces. To configure replication manually, consult
the documentation supplied with your replication tools.
Using Replication in Domain-based DFS Namespaces
The Distributed File System snap-in in Windows Server 2003 provides a
user interface for creating the FRS topology and schedule on servers
running Windows Server 2003. Using FRS in a domain-based DFS namespace
is optional; you can also replicate files by copying them manually or
by using non-Microsoft replication tools.
Please post FRS related questions to
microsoft.public.windows.server.dfs_frs and prefix the subject line
with "FRS:" to make it easier to spot. Note that FRS is used to
replicate SYSVOL on domain controllers and DFS root and link targets.
DFS Replication is a new file replication engine in
Windows Server 2003 R2. It is used to replicate folders between
computers with or without DFS Namespaces.
For additional FRS resources, please visit
For additional DFS Replication resources, please visit
This posting is provided "AS IS" with no warranties, and confers no
Post by mwest
Hi, Is there such a thing?
I thought I found it in an article about replication, but that turned out to
be about having multiple copies of the files.
I.E. Who cares if you have ten copies of a file if you can't get to it.
Win2k3 domain with two or more DC's
Multiple file servers
Multiple "Domain DFS roots" created on the PDC
If the PDC is offline can anyone get to a drive mapping of
I thought that since they were created on a DC that any of the DC's could
fill the DFS requests.
It seems that when this DC is offline so is DFS, even though there are other
Is there a way of making DFS Fault Tolerant?