My Basic Knowledge: Windows Server 2012 imbues Hyper-V Failover Clusters

Enhanced Virtual Machine Mobility
VM mobility is critical in a private cloud environment – and represents the heart of cloud computing. Windows Server 2012 Failover Clustering enables several VM mobility options and supports Live Migration, Quick Migration, Storage Migration and Hyper-V Replica. You could do Quick migration with Windows Server 2008. You could do Live Migration with Windows Server 2008 R2. With Windows Server 2012, you can still do Quick Migration and Live Migration, but the latter has been improved so that you can do more than one simultaneous Live Migration at a time within the same cluster.

Windows Server 2012 also has two new VM migration capabilities: Storage Migration and Hyper-V Replica. Storage Migration allows you to move VM storage to a different location while keeping the VM compute component on the same node in the cluster. You can even do this while the virtual machine is still running. Another new and cool VM mobility feature is Hyper-V Replica, which is a disaster recovery tool. With Hyper-V Replica, you can replicate VMs between source and destination Hyper-V servers, which can be located anywhere. Changes to the VMs are replicated to the Replica Hyper-V servers every 5 minutes. If there is a failure on the primary Hyper-V server, you can quickly start the VM on the replica Hyper-V server and the data loss will be limited to less than the last five minutes.

Intelligent Monitoring of Applications Hosted on Guest VMs
Hyper-V and Failover Clustering make possible higher availability to workloads running in VMs by providing a way for you to monitor applications running inside the VMs from the host Hyper-V server. Using this method of host-based monitoring, Hyper-V and Failover Clustering can detect whether services that are running in the VMs are running correctly and if they are not, enable automatic actions such as restarting the entire virtual machine or just restarting the service running in the VM.

New Guest Clustering Options
You can create a guest cluster by running the Failover Clustering Role in the VMs that are running in your physical cluster. In fact, you can create a guest cluster on Hyper-V servers that aren’t even members of a physical cluster. Prior to Windows Server 2012, storage for guest clusters could only use iSCSI for shared storage. With Windows Server 2012, you can use up to 4 Virtual Fibre Channel HBAs per node in your guest cluster. Note that the HBA on the Hyper-V host must meet certain requirements, such as support for NPIV. NPIV (N_Port ID Virtualization) is used to expose the Guest ports on the HBA to the Hyper-V server.

Improved Placement after Failover
Moving large numbers of VMs from one or more nodes in a cluster to other nodes used to be difficult prior to Windows Server 2012. Now moving VMs can be triggered and done on a controlled basis or in response to a failure. Windows Server 2012 has the intelligence to determine the resources (such as memory) that are available on each cluster node before making placement decisions.

Prioritized VM Failover
You can set VM priorities to control the order in which virtual machines fail over or power up. This enables you to give higher priority VMs the resources they need while lower priority VMs are given resources as they become available. This makes for an efficient transition process for cluster workloads.