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Failover Clustering Overview
Published: February 29, 2012
Updated: May 1, 2013
Applies To: Windows Server 2012
This topic provides an overview of the Failover Clustering feature in Windows Server 2012. Failover clusters provide high availability and scalability to many server workloads. These include server applications such as Microsoft Exchange Server, Hyper-V, Microsoft SQL Server, and file servers. The server applications can run on physical servers or virtual machines. This topic describes the Failover Clustering feature and provides links to additional guidance about creating, configuring, and managing failover clusters that can scale to 64 physical nodes and to 8,000 virtual machines.
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A failover cluster is a group of independent computers that work together to increase the availability and scalability of clustered roles (formerly called clustered applications and services). The clustered servers (called nodes) are connected by physical cables and by software. If one or more of the cluster nodes fail, other nodes begin to provide service (a process known as failover). In addition, the clustered roles are proactively monitored to verify that they are working properly. If they are not working, they are restarted or moved to another node. Failover clusters also provide Cluster Shared Volume (CSV) functionality that provides a consistent, distributed namespace that clustered roles can use to access shared storage from all nodes. With the Failover Clustering feature, users experience a minimum of disruptions in service.
Failover clusters in Windows Server 2012 are managed by using the Failover Cluster Manager snap-in and the Failover Clustering Windows PowerShell cmdlets. File shares on file server clusters can additionally be managed by using the tools in File and Storage Services.
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Highly available or continuously available file share storage for applications such as Microsoft SQL Server and Hyper-V virtual machines
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Highly available clustered roles that run on physical servers or on virtual machines that are installed on servers running Hyper-V
New and changed functionality in Failover Clustering supports increased scalability, easier management, faster failover, and more flexible architectures for failover clusters.
The following table summarizes Failover Clustering functionality that is new or changed since Windows Server 2008 R2. For detailed information, see What's New in Failover Clustering.
| Feature/functionality | New or improved | Description |
|---|---|---|
|
Improved |
Scales to 64 nodes and 8,000 virtual machines per cluster |
|
|
Management of large-scale clusters by using Server Manager and Failover Cluster Manager |
New |
Provides GUI tools to streamline management and operation of large-scale clusters |
|
Management and mobility of clustered virtual machines and other clustered roles |
New |
Helps allocate cluster resources to clustered virtual machines and other clustered roles |
|
Improved |
Improves CSV setup and enhances security, performance, and file system availability for additional cluster workloads |
|
|
New |
Provides CSV storage and integrates with File Services features to support scalable, continuously available application storage |
|
|
New |
Applies software updates across the cluster nodes while maintaining availability |
|
|
New |
Extends clustered virtual machine monitoring to the applications that run in the clustered virtual machines |
|
|
Improved |
Validates Hyper-V and CSV functionality and performs faster |
|
|
Improved |
Increases cluster resiliency and supports a wider range of deployments |
|
|
Improved |
Simplifies quorum setup and increases the availability of the cluster in failure scenarios |
|
|
Improved |
Allows migration of virtual machines from Windows Server 2008 R2, migration to CSVs, and reuse of existing storage |
|
|
New |
Integrates Failover Clustering with additional server functionality |
|
|
Improved |
Allows scripting of Failover Clustering functionality that was introduced in Windows Server 2012 |
A failover cluster solution must meet the following hardware requirements:
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Hardware components in the failover cluster solution must meet the qualifications for the Certified for Windows Server 2012 logo.
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Storage must be attached to the nodes in the cluster, if the solution is using shared storage.
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Device controllers or appropriate adapters for the storage can be Serial Attached SCSI (SAS), Fibre Channel, Fibre Channel over Ethernet (FcoE), or iSCSI.
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The complete cluster configuration (servers, network, and storage) must pass all tests in the Validate a Configuration Wizard.
 Note |
|---|
| In the network infrastructure that connects your cluster nodes, avoid having single points of failure. |
For more information about hardware compatibility, see the Windows Server Catalog.
For more information about the proper configuration of the servers, network, and storage for a failover cluster, see the following topics:
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You must follow the hardware manufacturers' recommendations for firmware updates and software updates. Usually, this means that the latest firmware and software updates have been applied. Occasionally, a manufacturer might recommend specific updates other than the latest updates.
The Failover Clustering feature can be used on all editions of Windows Server 2012, including with Server Core installations.
In Server Manager, use the Add Roles and Features Wizard to add the Failover Clustering feature. Optionally you can install the Failover Clustering Tools (also part of the Remote Server Administration Tools, or RSAT) on a local or a remote computer that is running Windows Server 2012 or Windows 8 and that has network connectivity to the failover cluster. The Failover Clustering Tools include the Failover Cluster Manager snap-in, the Failover Clustering Windows PowerShell cmdlets, the Cluster-Aware Updating (CAU) user interface and Windows PowerShell cmdlets, and related tools. For general information about installing features, see Install or Uninstall Roles, Role Services, or Features.
To open Failover Cluster Manager in Server Manager in Windows Server 2012, click Tools, and then click Failover Cluster Manager.
The following table provides additional resources on the web about the Failover Clustering feature in Windows Server 2012. Additionally, see the content on failover clusters in the Windows Server 2008 R2 Technical Library.
