Exchange Server 2007 : Configuring Cluster Services with Server 2008

Configuring Cluster Services with Server 2008

Some people might wonder whether it is better to use Server 2008 over Server 2003. This is logically true. There are enhancements with the clustering services, now called Failover Clustering, that can assist you in creating a more stable and secure cluster for CCR. Some of the new features are multiple subnets, support for geo-clusters, failover across two subnets, and support for IPv4 and IPv6.

In addition, there is a new Failover Cluster Management console based upon the MMC 3.0 changes, shown in Figure 1.

Figure 1. The Failover Cluster Management console.

There is a new quorum model that allows four different hybrids from which to choose:

• Node Majority— For use with clusters with an odd number of nodes (for use with clusters of three or more), which is really only helpful in an SCC situation (even though you can use it for CCR, it isn’t practical because you can use the file share witness and not waste an entire system acting as a node).

• Node and Disk Majority— For clusters with an even number of nodes. Each node gets a vote, as does the witness disk, which might reside on shared storage.

• Node and File Share Majority— For clusters with special configurations, which is the equivalent of the Majority Node Set that we have with Server 2003, and the one we use for CCR.

• No Majority: Disk Only— This is what they might call traditional shared quorum clustering. It can sustain a failure of all the nodes except one. It cannot sustain a failure of the quorum disk. (Note that although this option is available, the instructions clearly say, “This configuration is not recommended because the disk is a single point of failure.”)

To perform the preparation process for the CCR, setup on Server 2008 requires some of the same steps for Server 2003.

To configure cluster services, perform the following:

After you have the prerequisites in place, you need to proceed with the creation of the failover. To do this, perform the following:

1.	On the active server click Start, Administrative Tools, and then select Failover Cluster Management.
2.	This will launch the Failover Cluster Management console. Under Management you will see a link to Create a Cluster. Select that link.
3.	The Create Cluster Wizard will launch. On the Before You Begin screen, you are given information about the wizard and to ensure you are prepared to move forward. When you have read the information, click Next.
4.	On the Select Servers screen, shown in Figure 2, you are asked to locate the servers you want for the cluster. In this case, you should have two servers selected. Then click Next. Figure 2. Selecting your servers for the two-node cluster.
5.	You are taken to the Access Point for Administering the Cluster screen. You are asked to provide a cluster name (which is not the name of the cluster that will be accessed by Outlook clients; that name is configured when you perform the install of the active and passive mailbox nodes). You are also asked to provide an IP address for administrative connectivity. After these are set, click Next.
6.	From the Confirmation screen, you can confirm the settings you have chosen, and click Next.
7.	You are able to watch the process as the new cluster is created. Then you are taken to the Summary pane, where you can select View Report for a detailed report of the process, and click Finish.

Now that you have the failover cluster in place, certain aspects still need to be configured. For example, you need to select which interface is public and which is private (that is, for the heartbeat that lets each side of the node know that the other is alive and well).

To begin, open the Failover Cluster Management tool, expand Networks, and then open the properties page of the public network interface, as you can see in Figure 3. You might want to make changes to the name to make it easily identifiable as the public side. Then make sure you select the radio button, Allow the Cluster to Use This Network, and the checkbox, Allow Clients to Connect Through This Network.

Next, open the private network interface and do the same, although deselect the checkbox to allow clients to connect through this network.

Configuring the File Share Majority quorum is easier in Server 2008 because there is a wizard now. You still need to create the file share as we noted earlier, typically on a Hub Transport server. Make sure the cluster account receives the proper Full Control permissions over the share. With the share created, you can open the wizard to configure the quorum to use that model and to use the UNC for the share. Perform the following:

1.	Open the Failover Cluster Manager on one of the two nodes.
2.	From the Actions pane, select More Actions, and you will see the Configure Cluster Quorum settings. Click this to open the wizard.
3.	To begin with, you are shown the Before You Begin screen, where you can read a bit about configuration of the quorum. When you are ready, click Next.
4.	You are taken to the Select Quorum Configuration screen shown in Figure 4, which has the four options we discussed earlier. The third one, Node and File Share Majority (for clusters with special configuration), is the one we want for the CCR cluster. Select that radio button and click Next. Figure 4. Selecting the quorum type you require.
5.	Under the Configure File Share Witness screen, you are asked to provide the UNC path (or Shared Folder Path) to the folder you shared out. Type that in, or Browse for the location, and click Next.
6.	The Confirmation screen simply asks you to verify the cluster quorum. Click Next.
7.	After the configuration completes, click Finish.

The next part of the process is to validate the cluster functions properly. To do this, perform the following:

1.	Open the Failover Cluster Manager on one of the two nodes.
2.	From the Management section, click the Validate a Configuration link to open the wizard.
3.	The Before You Begin screen provides information on the validation process; you can read through this and click Next.
4.	You are asked to select a set of servers to validate. Choose the two servers in your cluster and click Next.
5.	You are taken to the Testing Options screen, shown in Figure 5. You are given the option to run all tests or run selected tests. It’s your decision, but perhaps the first time you should run all tests (which is recommended) and click Next. Figure 5. The Testing Options screen.
6.	You are taken to the Confirmation screen, and you can see the list of tests that will be performed on your systems. When ready, click Next.
7.	The Validating screen displays. You see your cluster as it is put through one test after another, and you can see the results, shown in Figure 6. Figure 6. Selecting your servers for the two-node cluster.
8.	After completion, you are taken to the summary page, where you can scroll through and see a report of the process (shown in Figure 7). You can also click View Report to see a detailed report of the testing. When you are done, click Finish.

Figure 7. The Failover Cluster Validation Report.

At this point, you are ready to perform the installation of Exchange 2007 for the Mailbox server roles for the active and passive side.

The installation begins like a typical installation:

After you have the active side installed, you next step is to install the Passive Clustered Mailbox role. Follow the same steps but choose the passive mailbox.

Making Changes to the Transport Dumpster

In the RTM of Exchange 2007, you could configure the transport dumpster through the EMS using the Set-TransportConfig cmdlet. However, in SP1 there is a GUI method now through the EMC.

The default configuration for the dumpster is to have the Maximum Size Per Storage Group (MB) option set at 18 and the Maximum Retention Time (Days) option set at 7. If you feel the need to alter this, you can. To do this, you go through the Organization Settings work center, click the Hub Transport node, and under the Global Settings tab you can view the properties of the Transport Settings. On the General tab (shown in Figure 8), you can make changes.

Confirm the CCR Cluster Is Performing Properly

With the RTM version of Exchange, we had to use the EMS to determine whether our CCR cluster was healthy, but now there are ways to check within the EMC. For example, much like with LCR, you can view the properties of the server, and there is now a Clustered Mailbox tab. This shows you if the cluster is online and which node is active.

If we view the properties of the storage group, we can see a new Cluster Continuous Replication tab and see whether our Copy status is healthy.

A new wizard in SP1 called the Manage Clustered Mailbox Server Wizard allows you to move the mailbox to another node, and stop or start the clustered mailbox server. This wizard can be located in the Actions pane if you select the CMS from the Server Configuration work center.