Windows Server 2012 R2 (Hyper-V) what’s new?

Hyper-V Generation 2 Virtual Machines
- Virtual Machines will be legacy free and based on UEFI
- Boot from virtual SCSI controller and/or synthetic network adapters
- Secure Boot as standard
- Faster Virtual Machine boot times
- Supported guest operating systems are x64 Windows 8 / x64 Windows Server 2012 / x64 Windows 8.1 and x64 Windows Server 2012 R2.

Faster Live Migration
- Live Migration Compression of the host before it’s sent over the lan reduces the migration time by 50%.
- Live Migration with SMB Direct over high speed networks (RDMA) allows for faster live migrations.

Other new features are:
- Automatic Guest Virtual Machine Activation when the virtual machine is running inside an activated host running Windows Server 202 R2 Datacentre.
- Shared VHDX allows two virtual machines to share the same disk catering for guest clustering inside virtual machines without using iSCSI or virtual fibre adaptors.
- Linux Guest OS now supports dynamic memory and live backups.
- Hyper-V Replica 2.0 can replicate to a third Hyper-V host every 30 seconds / 5 minutes or every 15 minutes.
- Online resizing VHDX allowing the expansion and reduction of VHDX files while the virtual machine is running.
- Deduplication of Virtual Machines.
- Storage Quality of Service (QoS) can limit the IOPS per virtual machine
- Live Virtual Machine Cloning and Exporting

More information can be found here;