3. Windows Azure Infrastructure-as-a-Service (IaaS) is
built on the same hypervisor as Windows Server. This
means that there is complete virtual machine
compatibility between the private cloud, partner public
clouds, and the Microsoft-owned public cloud.
Customers can now decide “Where do I want my
service to run today?”

4. A compression engine is built into Live Migration in Windows
Server 2012 R2 Hyper-V. The CPU in hosts is often
underused, so this engine makes use of this spare resource
to compress the memory of virtual machines that are being
moved before the memory pages are copied across the Live
Migration network. Hyper-V will monitor the utilization of CPU
resources on the host and throttle compression to prioritize
guest services. Enabling Live Migration compression on
networks with 10 Gbps or less without Remote Direct
Memory Access (RDMA/SMB Direct) support will greatly
reduce the time it takes to move virtual machines (not
including storage migration).

5. Live Migration can be configured to leverage SMB Direct (Remote Direct
Memory Access, or RDMA) on hosts that that NICs with support for this
feature. This feature will provide hardware offloaded accelerated copy of
memory pages using SMB 3.0 NICs. This can take advantage of SMB
Multichannel to span multiple networks. SMB Direct Live Migration
provides the fastest way to live migrate virtual machines (not including
storage) from one host to another. Memory speed will be the rare
bottleneck on a host with PCI3 support and three RDMA NICs for Live
Migration! This feature allows very interesting new architectures,
especially where organizations have decided to deploy SMB 3.0 storage
with support for SMB Direct. Investments in RDMA can be leveraged to
move virtual machines very rapidly over these physical networks (with
QoS applied for SLA). For example, Cluster Aware Updating (CAU) will be
performed much more rapidly.

6. Virtual hard disks of the VHDX format that are attached to the SCSI
controllers of virtual machines can be resized without shutting down the
virtual machine. VHDX files can be up- and down-sized. Downsizing can
only occur if there is unpartitioned space within the VHDX. This feature
supports both Windows and Linux guests.
Live Resizing of VHDX files will be of huge value to those running mission
critical workloads. It will also offer a new self-service elasticity feature for
clouds.

7. New storage metrics for IOPS have been added to WS2012 R2. With
these metrics, you can determine the IOPS requirements of virtual
machines and put caps on storage activity. This will limit how much
physical disk activity that virtual machines can create, and therefore limit
the damage that activity spikes can cause to other virtual machines and
their guest services.
One of the concerns with shared storage is the possibility of a race for
storage throughput. Enabling Storage QoS will limit the damage that
any virtual machine or tenant can do in a cloud.

8. WS2012 R2 Hyper-V allows you to clone a running virtual machine. This
will create an exact copy of the virtual machine that is stored in a saved
state. This feature supports GenerationID.
That means you can use Live Virtual Machine Cloning to create Active
Directory supported clones of a virtual domain controller that is not the
PDC Emulator.
This feature will be useful for situations where you need to debug a
production system or you want to perform tests, such as guest OS
upgrades.

9. You can export a virtual machine with a checkpoint (formerly known as a
snapshot)
You can also export a checkpoint of a virtual machine.

10. Dynamic Memory will be supported in Linux Guest OS’s on Windows
Server 2012 R2 Hyper-V. This will give much better memory optimization
for Linux virtual machines, and it'll allow for much greater densities.
Linux distributions with this built-in Linux Integration Services for Hyper-
V HyH support are already available.
There will be support for online backup of Linux guest OSs. This is not
Volume Shadow Copy Service (VSS) for Linux, and it does not give an
application consistent backup. Instead, a file system consistent backup is
created by freezing the file system. This feature does require an upgrade
of any already deploy Linux Integration Services.

11. You can configure up to 64 virtual machines to share a single VHDX file
on some shared storage (such as CSV or SMB 3.0). The VM sees the
shared VHDX as a shared SAS disk with SCSI-3 persistent reservations.
This is for data volumes to create guest clusters, and not for shared boot
volumes. It works with down-level guest OSs, such as W2008 R2 with
the WS2012 R2 Hyper-V Integration Components installed. This feature
is supported by Service Templates in VMM 2012 R2.
This will really simplify guest clustering, where virtual machines are used
to create a highly available service at the application layer. This could
eliminate the need for guest attachment to physical LUNs and will be
accommodating to self-service deployment within a cloud.

12. The default period for asynchronous replication of the Hyper-V Replica Log is every 5
minutes, but this can be changed to every 30 seconds or every 15 minutes. This allows
companies to choose the allowed recovery point objective (RPO) – the maximum
allowed amount of data loss in time. Hyper-V Replica can now be extended to a third
site. This is an A-B-C extension, and not an A-B/A-C extension. For example, a
company might replicate virtual machines from the primary site to a local secondary
site. This might be configured to happen every 30 seconds. Replica virtual machines in
the secondary site might be replicated to a distant third site (such as a hosting
company) maybe every 15 minutes. In the event of an unplanned failover, this would
give an RPO of 30 seconds in the secondary site and an RPO of 15 minutes and 30
seconds in the third site. The performance and scalability of Hyper-V Replica has been
improved. Maintaining historical copies of virtual machines in the secondary site is
costly (IOPS). This has been reduced, so maintaining historical copies of your replica
VMs will not punish your storage in the secondary site.

13. The criticized virtual machine connection of the past (VMConnect.exe
process) is being replaced by a Remote Desktop experience that is built
into the virtualization stack. This has no dependency on the virtual
machine’s networking. By default, this feature is disabled in WS2012 R2
Hyper-V and enabled in Windows 8.1 Client Hyper-V. Things that Remote
Desktop VM Connect allow you to do include:
Copy & paste text and images.
Copy files to/from the client desktop.
Do session-based USB redirection.
This means you might use a USB stick to copy files.
It is not a USB dongle solution.

14. You can live migrate a virtual machine from WS2012 Hyper-V to WS2012
R2 Hyper-V. This could eliminate downtime when deploying WS2012 R2
Hyper-V. For example, you can deploy a WS2012 R2 Hyper-V host/cluster
alongside an existing WS2012 Hyper-V host/cluster. You can then live
migrate the virtual machines from the older platform to the new platform
with zero downtime to the availability of the services provided by the
virtual machines.
Note that you cannot do a Live Migration downgrade from WS2012 R2
Hyper-V to WS2012 Hyper-V. It is a one-way upgrade path.

15. This is the first time that Windows Server (and thus Hyper-V) is being
developed with and released at or close to the same time as System
Center. There has been closer than ever before cooperation within
Windows Server and System Center (WSSC).
That means you can deploy System Center immediately and follow it up
with WS2012 R2 Hyper-V, without the long delays of the past.

16. Similar to the StorSimple appliance, Windows Server 2012 R2 can measure
the “heat” of storage needs. “Hot” portions of files (block levels) are
moved to Solid State Drives (SSDs) and cold data to slower magnetic
drives.
This allows a favorable balance between capacity and performance.
Administrators can assign files to specific storage tiers. This could be a
master “gold” vhd for a business customer.

17. Useful for connecting the on-premises datacenter to Windows Azure, this
feature is now built into Windows Server 2012 R2.

18. 64 Tb is the addressable space of Windows Server 2012, and a .VHDX can
be 64 Tb in size. Now .VHDX virtual disks can be used with iSCSi in
Windows Server 2012 R2.

19. Performance gains of over 50% can be had by having process awareness
of the common blocks that are referenced by deduplication.

20. If the parent partition is activated, and if it is running Windows Server
2012 R2, the Windows Server 2012 R2 guest partition is automatically
activated without any intervention.

21. PowerShell 4.0 adds new cmdlets for:
• VPN configuration
• Start Screen customization
• DISM
• NAT
• TPM
• WMI
• TCP/IP
• Systems Management
• Storage