The Failover Cluster Management tool included with Windows Server 2008 allows you to create and manage server clusters. Scott Lowe provides an overview.
Although all editions of Windows Server 2008 include Network Load Balancing, only the Enterprise Edition and the Datacenter Edition include failover clustering capabilities to achieve higher levels of availability. A cluster allows you to establish high availability for general services or for specific applications. The Failover Cluster Management tool included with Windows Server 2008 enables you to create and manage clusters. Here's an overview of that tool.(Note: Clustering is a relatively complex topic that requires an understanding of hardware requirements, shared storage, and other concepts. Explaining clustering in detail would require an article just about that topic, so in this overview of the Failover Cluster Management tool, I'll stick to explaining the most important clustering concepts in relation to the console.)
Installation and task overview
You need to take the following steps to implement clustering in your environment (this article does not go over the full installation of cluster services):
- Make sure your hardware is compatible with Windows Server 2008 clustering.
- Configure volumes on your shared storage connected and visible to both servers.
- Install the Failover Clustering feature on each of your intended cluster nodes.
The Failover Custer Management tool
The screen is configured much like any other modern Microsoft management tool with a navigation pane on the left-hand side of the screen, an object-focused work pane in the middle of the screen, and an Actions pane in the right-hand side of the window.
The left pane shows the cluster hierarchy and various objects in a cluster such as nodes, services, storage, networks, and so on. Clicking an object in the left pane displays the contents of the object in the right pane. For example, click the Active Resources object for a particular node, and the right pane lists the active resources for the node along with their state, owner, group, and other properties.
The tasks you can accomplish with the Failover Cluster Management tool include the following:
- Create or destroy a cluster.
- Add and remove nodes to and from a cluster.
- Add disks to a cluster.
- Add services to or remove them from a cluster.
- Configure quorum disk rules.
- View events related to all cluster components.
The Failover Cluster Management tool includes these four menus:
- File. The File menu is very sparse in this console and only has Options and Exit commands. Options gives you a way to clean up after the MMC.
- Action. The Action menu holds most of the cluster management tasks in the Failover Cluster Management tool. The commands in the File menu vary according to the object you have selected in the panes below. In all cases, you can choose Open Connection from the File menu to open a connection to an existing cluster or to create a new cluster. Your best bet is to right-click specific objects in the interface and work with the context menu for the selected object; this helps you to avoid possible mistakes.
- View. Use the View menu to customize the look of the management console.
- Help. Use this menu to view the Failover Cluster Management tool Help content.
The Failover Cluster Management tool includes a toolbar with the following buttons:
- Back. Navigate back through the console.
- Forward. Navigate forward through the console.
- Up One Level (not always shown). Move to the next higher level in the tree. This is only available when a domain is selected.
- Show/Hide Console Tree. Toggle the display of the left-hand navigation pane.
- Properties. Open the properties for the selected item.
- Refresh (not always shown). Refresh the current view.
- Help. Open the Help content.
The console tree
Although the Failover Cluster Management tool isn't an MMC snap-in, it looks and functions like one, so I'll use the same terminology for it as for a typical snap-in and refer to the left pane as the console tree. In the console tree, you'll find each open cluster connection displayed in its own hierarchical tree. The tree is comprised of the following objects.Services And Applications
Choose this navigation option to get a list of the services and applications that have been configured for high availability in the cluster. You'll see this object in action later in this article.Nodes Each node in the cluster is represented in the console tree underneath the Nodes option (Figure B). When you select a node, all of the details for that node appear in the work pane in the middle of the screen. If you want to add a disk to the cluster, right-click this option and, from the shortcut menu, choose Add Node.
Details of one node in this cluster.Storage Selecting the Storage option in the navigation pane shows you, in the work pane, a list of all of the disks shared in the cluster (Figure C). If you want to add a disk to the cluster, right-click this option and, from the shortcut menu, choose Add A Disk.
A list of the storage resources present in the cluster.Networks Each network in the cluster is represented in the console tree in the Networks option (Figure D). When you select a network, all of the details for that network appear in the work pane in the middle of the screen.
Details of one network in the cluster.You can indicate whether the cluster should use a particular network by right-clicking an individual network entry and, from the shortcut menu, choosing Properties. On the Properties page, select the option next to Allow The Cluster To Use This Network (Figure E).
Change the configuration of a network.Cluster Events
This link houses all of the events related to the cluster service.
Working with the tool's wizards
The Failover Cluster Management tool provides wizards that help you accomplish common tasks such as setting up a cluster, adding nodes, adding groups, and adding resources. I'll explain how to start each wizard and discuss what information you'll need in each one.Validating your hardware configuration
Before you create a cluster, you should examine your infrastructure to make sure it's ready to support your new high-availability configuration. Start the Hardware And Infrastructure Validation Wizard via one of these methods:
- Choose Action | Validate A Configuration.
- Right-click Failover Cluster Management and, from the shortcut menu, choose Validate A Configuration.
- In the Actions pane, choose Validate A Configuration.
- When you first start the Failover Cluster Management tool, in the middle pane, choose Validate A Configuration.
Enter the names of the servers that will take part in the cluster.A couple dozen tests are run that validate your configuration, including enumerating your iSCSI or Fibre Channel host adapters, clustered network configuration, cluster member firewall exception configuration, and storage files system. You can run all of the tests if you like, or you can choose which tests to run (Figure G). (If you opt to run all of the tests, the process can take a bit of time.)
Decide which tests you want to run.After you make your selections, they will be listed for you to review. Once you confirm your choices, click the Next button to begin the analysis (Figure H).
Confirm your choices.
As the analysis proceeds, if an individual test passes, you receive notification in green text at the right-hand side of the test window; failed tests will appear in red. If you have failures, you can view a detailed report that explains the exact cause of an error. If all of the tests pass, click the Finish button to continue.
Creating a cluster
The goal of your management efforts is to cluster your servers. Microsoft provides a wizard called Create Cluster to move you down this path.
The various ways to start the Create Cluster Wizard include the following options:
- Choose Action | Create A Cluster.
- Right-click Failover Cluster Management and, from the shortcut menu, choose Create A Cluster.
- In the Actions pane, choose Create A Cluster.
- When you first start the Failover Cluster Management tool, in the middle pane, choose Create A Cluster.
The first screen of the wizard simply provides an overview. Click the Next button to proceed. Each step of the wizard is outlined below.Select Servers Choose the servers that will comprise the cluster. Use the Browse button to browse Active Directory for servers. (Figure I)
Provide the names of the servers that will take part in the cluster.Access Point For Administering The Cluster Provide the name of the new cluster and, when requested, provide the IP address that will be used to address the cluster. (Figure J) Remember: Although individual servers retain their IP addresses, the cluster gets an IP address, too.
Enter a Name and an Address for your cluster.Confirmation and cluster creation Confirm your settings (Figure K).
Confirm your settings.Once you confirm your settings, the cluster will be created, and you will be presented with a summary screen showing you the results of the creation process. If anything goes awry during the creation process, you can view a detail report that is generated during creation. Click the Finish button in the wizard when you're done. At this point, if you were to open the Failover Cluster Management tool, you would see a screen like the one shown in Figure L, which verifies that the cluster was successfully established.
The management console's navigation pane after a cluster is created.
Adding services to a cluster
To add a service, open the Failover Cluster Management tool, browse to your cluster and right-click Services And Applications. From the shortcut menu, choose the Configure A Service Or Application option. This starts the High Availability Wizard.Select Service Or Application After the introduction page of the wizard, you're asked to choose the service or application that you want to make highly available. Check with your software vendor to determine cluster compatibility. The next steps of the wizard will change depending on what you select on this page (Figure M).
Choose the service or application to make highly available.Client Access Point For each service you configure, you must specify how clients will access the service. Remember that the clustered service will appear as a single entity to client computers. Name the service and provide the service with a unique IP address (Figure N).
Once you provide this information and click Next, your selection will be validated.Select Storage Next, choose the shared storage device that will be used by the chosen service (Figure O).
Select shared storage.Once you make this selection, you have the opportunity to confirm your selections. Afterwards, the wizard will make the selected service highly available on your network (Figure P).
The service is now highly available.In Figure Q, you can see the shared file server in action.
The shared file server.
Task listNow that you are familiar with the Failover Cluster Management tool, you're ready to start creating and managing clusters. Table A lists common cluster administration tasks and outlines how to accomplish the tasks with the Failover Cluster Management tool. Table A
|Validate your cluster's hardware configuration||
|Create a cluster||
|Add nodes to a cluster||Choose your cluster, right-click Node and, from the shortcut menu, choose Add Node.|
|Repair a node||Right-click the node and choose More Actions | Stop Cluster Service. Confirm your action. Configure the Cluster Service for manual startup (if needed) on the node. Repair and reboot the node, reconfigure the service for automatic startup, then right-click the node in the Cluster Administrator and choose More Actions | Start Cluster Service.|
|Evict a node||Right-click the node and choose More Actions | Stop Cluster Service. Right-click the node and choose More Actions | Evict.|
|Pause or resume a node||Right-click the node and choose either Pause or Resume.|
|Stop or start the Cluster Service||Right-click the node and choose either More Actions | Stop Cluster Service or More Actions | Start Cluster Service.|
|Set service failover policy||Right-click the service and choose Properties. Click the Failover tab.|
|Set service failback policy||Right-click the service and choose Properties. Click the Failover tab.|
|Migrate services to another node||Right-click the cluster and choose More Actions | Migrate Services And Applications.|
|Rename a cluster||Right-click the cluster and choose Rename.|
|Create a new resource||Right-click a group and choose New | Resource to start the New Resource Wizard.|
|Delete resource||Take the resource offline, then right-click the resource and choose Delete.|
|Change resource online status||Right-click a resource and choose Take Offline or Bring Online.|
|View service dependencies||Right-click the service and click Show Dependency Report.|
|Specify nodes that can own resource||Right-click the resource and choose Properties. On the Advanced Policies tab, indicate which nodes can own the resource.|
|Rename resource||Right-click the resource and choose Properties. Enter the resource's new name.|
|Simulate resource failure||Right-click the resource and choose More Actions | Simulate Failure Of This Resource.|
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Since 1994, Scott Lowe has been providing technology solutions to a variety of organizations. After spending 10 years in multiple CIO roles, Scott is now an independent consultant, blogger, author, owner of The 1610 Group, and a Senior IT Executive with CampusWorks, Inc. Scott is available for consulting, writing, and speaking engagements and can be reached at firstname.lastname@example.org.