Set Up DFS Replication
Because Emily implicitly chose to configure replication by immediately adding
a second folder target to her namespace, the Replicate Folder Wizard prepopulates
many fields with information from the folder. Clicking Next from the first screen
causes the wizard to determine which folders are available to be members of the
replica set. Any servers that contain folder targets and don't run R2 are
ineligible to join the replica set.
Clicking Next again takes Emily to the Primary Folder Target step, where she
chooses the folder that will initially be authoritative for the replica set.
Designating a primary folder means that if there's any content already in the
replica set, the contents of the primary folder will override the preexisting
content in the replica set. Files that don't exist in the primary folder are
removed from view. Those files aren't deleted, but are moved to a hidden system
folder named DfsrPrivate\PreExisting under the folder root, as a DFSR log message
tells you in clear English. (Concise, informative logging is one of the much-needed
improvements DFSR offers over FRS.)
In the Topology Selection step, which Figure
2 shows, Emily can choose from a huband-spoke replication topology, a full
mesh topology, or build her own custom topology. A hub and spoke topology (where
multiple branches replicate with one or more centralized servers) is more scalable,
but a mesh topology is highly fault tolerant. In a mesh topology, each node
is connected directly to the other nodes; consequently, in larger configurations
a mesh topology can generate a lot of overhead for the servers. Since she has
only four servers' content to replicate, however, Emily chooses the mesh topology.
The next step lets Emily tailor the amount of bandwidth that replication consumes.
Because she doesn't need to replicate data on less than 24 hours notice and
the company's WAN circuits are only lightly used after working hours, she decides
to replicate with a bandwidth of 64Kbps—a trickle—during the day
and with full bandwidth between 8 P.M. and 7 A.M. She clicks the Days and Times
button, then clicks Edit Schedule. In the Edit Schedule dialog box, which Figure
3 shows, she chooses a day and time by dragging the cursor over a block
of hours, then selects a bandwidth to use during that period and clicks Add.
The final screen of the wizard appears, and with the configuration complete,
she reviews her choices by clicking the Create button to create the replication
group and schedule. The Errors tab provides details on any errors in her configuration.
Figure 4 shows the DFS Management
snap-in focused on the ISOs replication group Emily created. In the Actions
pane, she can add members, change or verify the topology, delegate permissions,
edit the replication schedule, and pretty much alter anything she initially
configured. The Connections tab in the middle pane provides details of the replication
connections, which were previously available only through the complicated Ultrasound
utility for monitoring FRS.
Replication might not begin immediately, regardless of the schedule, because
DFSR has preliminary work to do. It must create and populate a staging directory
with files to be replicated, and it must establish both inbound and outbound
connections with its other replica set members. The amount of time it takes
to complete these steps depends on the amount of data on the primary originating
share and on how much of that data already exists on the replica members.
When it's ready, DFSR begins replicating data.
Run Reports
Emily wants to create a diagnostic report to see how the initial replication
is coming along, so she clicks Create Diagnostic Report in the Actions pane.
She can choose to look at disk space used, backlogged transactions and files,
and replication efficiency, but accepts the default settings and gets the HTML
report shown in Figure 5. The report
reveals that she still has a little troubleshooting to do, because two servers
aren't reporting and the others are low on disk space.
Not Your Father's DFS
Windows 2003 R2's DFS Namespaces and DFSR service represent major improvements
in all aspects of DFS. Setting up and maintaining a namespace are much easier
than they've ever been. If limitations in DFS have prevented you from using
it in the past, it's time to revisit this capability.
| SOLUTIONS
SNAPSHOT
PROBLEM: You need an easy way to set up a replicated, fault-tolerant
data-publication system.
SOLUTION:
Use the new DFS Replication (DFSR) feature in Windows Server 2003
R2.
WHAT YOU NEED: Windows Server 2003 R2
DIFFICULTY: 3 out of 5
SOLUTION STEPS:
- Do prep work, including installing Windows 2003 R2 and upgrading AD
schema.
- Build a namespace.
- Add a namespace server.
- Add folder targets.
- Set up DFSR.
- Monitor replication by running reports.
|
End of Article
oalexis@dar.org April 16, 2007 (Article Rating: