What settings have been added or changed?

Improvements to stability and security to help maximize availability

 Configure your cluster so that the quorum is not a single point of failure. With improvements in failover clusters, you can use the two cluster models that previously existed—the quorum resource model and the majority node set model—or a "hybrid" of the two. For example, in a two-node cluster, you can specify that if the quorum disk (now called a "witness disk") becomes unavailable, the cluster continues running as long as the copies of the cluster configuration database on the two nodes remain available.

 Achieve greater reliability and availability because of improvements to the cluster infrastructure itself. The cluster infrastructure has been improved to help you achieve greater reliability and availability with failover clusters. For example, the software infrastructure that handles clustered resources will isolate dynamic-link libraries (DLLs) that perform actions incorrectly, minimizing impact to the cluster. As another example, the cluster will use enhanced methods to ensure consistency among copies of the cluster configuration database.

Improvements to the way a cluster works with storage

 Make additional disks available to the cluster while applications are online. You can modify resource dependencies while resources are online, which means you can make an additional disk available without interrupting access to the application that will use it.

 Obtain better performance and stability with your storage. When a failover cluster communicates with your SAN or DAS, it uses the least disruptive commands (avoiding SCSI bus resets). Disks are never left in an unprotected state, meaning that the risk of volume corruption is lowered. Failover clusters also support improved methods for disk discovery and recovery.

The types of storage connections that failover clusters support are Serial Attached SCSI (SAS), iSCSI, and Fibre Channel.

 Perform disk maintenance tasks more easily. "Maintenance mode" has been improved so that you can run tools to check, fix, back up, or restore disks more easily and with less disruption to the cluster.

Improvements to interfaces for working with shared folders

 Access-based enumeration: You can use access-based enumeration to hide a specified folder from users' view. Instead of allowing users to see the folder but not access anything on it, you can choose to prevent them from seeing the folder at all. You can configure access-based enumeration for a clustered shared folder in the same way as for a nonclustered shared folder.

 Offline access: You can configure offline access (caching) for a clustered shared folder in the same way as for a nonclustered shared folder.

 Clustered disks always recognized as part of the cluster: Whether you use the failover cluster interface, Windows Explorer, or the Share and Storage Management snap-in, Windows Server 2008 recognizes whether a disk has been designated as being in the cluster storage. If such a disk has already been configured in Failover Cluster Management as part of a clustered file server, you can then use any of the previously-mentioned interfaces to create a share on the disk. If such a disk has not been configured as part of a clustered file server, you cannot mistakenly create a share on it. Instead, an error indicates that the disk must first be configured as part of a clustered file server before it can be shared.

 Integration of Services for Network File System: The File Server role in Windows Server 2008 includes the optional role service called Services for Network File System (NFS). By installing the role service and configuring shared folders with Services for NFS, you can create a clustered file server that supports UNIX-based clients.

Improvements to networking and security

 Use IPv6, which is fully integrated into failover clusters. Failover clusters fully support IPv6 for both node-to-node and node-to-client communication.

 Use Domain Name System (DNS) without legacy NetBIOS dependencies. This simplifies the transport of server message block (SMB) traffic and means you do not have Windows Internet Name Service (WINS) and NetBIOS name-resolution broadcasts.

 Achieve better reliability through other improvements to networking. Because of improvements to networking, you can fine-tune the dependencies between a network name and associated IP addresses so that the network name will be available if either (not both) of the IP addresses is available. In addition, when nodes transmit and receive "heartbeats" to confirm that each node is still available, they use Transmission Control Protocol (TCP) rather than the less reliable User Datagram Protocol (UDP).

 Achieve enhanced security through security improvements and auditing of cluster access. Security improvements in failover clusters enhance authentication and encryption. In addition, you can use auditing to capture information about who accessed your cluster and when.

 Place clustered servers on different subnets: You can now place clustered servers on different IP subnets, which reduces the requirements for geographically dispersed clusters.

 Create additional security for intra-cluster communications: You now have the option either to digitally sign or encrypt all intra-cluster communication. By default, intra-cluster communication is digitally signed. Intra-cluster communication typically includes information about changes to the cluster configuration or to the state of clustered resources.