Windows Server 2008 R2 : Deploying Failover Clusters (part 3)

Adding Nodes to the Cluster

If additional nodes need to be added to the cluster after the initial cluster creation process, first join that server to the domain, add the failover clustering feature, configure the network interface cards and storage configuration per cluster specifications, and then perform the following steps:

Adding Storage to the Cluster

When shared storage is used with failover clusters, all of the LUNs or targets presented to the cluster hosts might not have been added to the cluster during the initial configuration. When this is the case, and additional storage needs to be added to the cluster, perform the following steps:

1.	Log on to one of the Windows Server 2008 R2 cluster nodes with an account with administrator privileges over all nodes in the cluster.
2.	Click Start, click All Programs, click Administrative Tools, and select Failover Cluster Manager.
3.	When the Failover Cluster Manager console opens, if necessary type in the name of the local cluster node to connect to the cluster.
4.	In the tree pane, expand the desired cluster Services and Applications group, select Storage, right-click Storage, and select Add a Disk.
5.	If suitable storage is ready to be added to the cluster, it will be listed in the Add Disks to a Cluster window. If a disk is listed, check the box next to the desired disk or disks, and click OK to add the disk(s) to the cluster. The disks will need to be basic disks and set to online in Disk Manager on one of the cluster nodes and should already have a single partition and drive letter. It is essential that drive letters used for cluster disks are not in conflict with any drive letters on any node in the cluster, including optical or external drives.
6.	After the process completes, if necessary change the drive letter of the new disk. Once this process completes, if Disk Manager is opened on the cluster nodes, disks will show as Basic and Reserved on all cluster nodes, but only the active cluster node will show the disk partition and drive letter information.
7.	Close the Failover Cluster Manager console.
8.	Click the Start button and select Computer.
9.	Review the list of disks on the cluster node and note that disks managed by the cluster are listed as Clustered Disks instead of Local Disks, as shown in Figure 7. Figure 7. Displaying the local and clustered disks on a cluster node.
10.	Close the Explorer windows and log off of the server.

Cluster Quorum Configuration

If all cluster nodes and shared storage were available during the creation of the cluster, the best-suited quorum model would have been automatically selected during the cluster creation process. In some cases, the selected quorum model might need to be changed if the cluster configuration changes by adding or removing nodes or by deploying geographically dispersed clusters. When the existing cluster quorum needs to be validated or changed, perform the following steps:

1.	Log on to one of the Windows Server 2008 R2 cluster nodes with an account with administrator privileges over all nodes in the cluster.
2.	Click Start, click All Programs, click Administrative Tools, and select Failover Cluster Manager.
3.	When the Failover Cluster Manager console opens, if necessary type in the name of the local cluster node to connect to the cluster.
4.	In the tree pane, select the cluster name; in the tasks pane, the current quorum model is listed.
5.	Review the current quorum model, and if it is correct, close the Failover Cluster Manager console.
6.	If the current quorum model is not the desired model, right-click the cluster name in the tree pane, click More Actions, and select Configure Cluster Quorum Settings.
7.	If the Before You Begin page opens, click Next, then on the Select Quorum Configuration page, select the option button of the desired quorum model or select the option button of the recommended model, and click Next to continue, as shown in Figure 8. Figure 8. Configuring the cluster quorum model for a failover cluster.
8.	If a quorum model contains a witness disk or file share, select the designated disk or specify the path to the file share, and click Next.
9.	On the Confirmation page, review the settings, and click Next to update the cluster quorum model for the failover cluster.
10.	Review the results on the Summary page, and click Finish to return to the Failover Cluster Manager console.
11.	Close the Failover Cluster Manager console and log off of the server.

Enabling Cluster Shared Volumes

When Hyper-V virtual machines will be deployed on Windows Server 2008 R2 failover cluster nodes and shared storage is used, the new Cluster Shared Volumes can be enabled for use with Hyper-V Live Migration configurations for designated virtual machines. Cluster Shared Volumes are currently only supported on failover clusters for Hyper-V and unlike other cluster shared storage, these designated volumes can be read and written to by all nodes in the cluster simultaneously. Obvious to some is the fact that when two separate systems can write to a single disk, corruption can occur and that is why this feature is only currently supported for Hyper-V and Live Migration. One important point to note is that for a virtual machine to use a Cluster Shared Volume, this feature must be enabled on the cluster and the virtual machine must use storage that has been added to the Cluster Shared Volume storage group prior to virtual machine creation.