Hyper-V Server 2012 R2: 9 New and Updated Features

Microsoft has significantly improved their virtualization platform Hyper-V Server 2012 R2. There are lots of new and improved features compared with previous versions. Now the Hyper-V hypervisor is more robust and reliable for enterprise. Hyper-V Server 2012 R2 supports the concept of a totally new architecture based on modern hardware with no emulated devices. This makes it possible to add a number of new features, such as secure boot for VMs and booting off of virtual SCSI or virtual network adapters. I will highlight a few exciting features of the latest version of Hyper-V which comes with Windows Server 2012 R2 as well as of course the standalone version Hyper-V Server 2012 R2.

At a glance, Microsoft has introduced and improved the following Hyper-V features which I have gathered from Microsoft Technet:

Hyper-V New and Updated Features and Functionalities

Hyper-V Replication Extension to Off-Site

You can configure extended replication with Hyper-V Server 2012 R2. In extended replication, your Replica server forwards information about changes that occur on the primary virtual machines to a third server (the extended Replica server). Hyper-V Server 2012 is currently limited to a single replication target. This makes it difficult to support scenarios like a service provider wanting to act both as a target for a customer to replicate and a source to replicate to another offsite facility.

Live Migration with Compression for Faster Migration

Hyper-V Server 2012 R2 improved the performance of live migrations by enabling compression of the data to reduce the total number of bytes transmitted over the wire. Tapping CPU resources for data compression could potentially impact other operations, so you’ll need to take that into consideration. The second option, SMB Direct, requires network adapters that support RDMA. Microsoft’s advice: If you have 10 GB available, use RDMA (10x improvement); otherwise, use compression (2x improvement). Compression is the default choice and it works for the large majority of use cases.

Dynamic Memory Support for Linux

Microsoft has improved a lot to support for Linux VMs. Now with Server 2012 R2, Hyper-V gains the ability to dynamically expand the amount of memory available to a running VM. This capability is especially handy for any Linux workload (notably Web servers) where the amount of memory needed by the VM changes over time. In environments with many Linux VMs, dynamic memory becomes even more critical to efficiently manage the total memory used by all running VMs. Hyper-V Server 2012 R2 also brings Windows Server backups to Linux guests.

Virtual Machine Direct Connect

Connecting to a running VM over RDP requires an active network connection, which you can’t always count on. In addition to an active network connection, the VM must have an IP address reachable by the system attempting to connect, a requirement with potential management and security issues depending on the environment in which you’re running. All this changes in Hyper-V Server 2012 R2 with the addition of VM Direct Connect. This feature allows a direct remote desktop connection to any running VM over what’s now called the VM bus. It’s also integrated into the Hyper-V management experience.

Live VHDX Resizing

In earlier versions of Hyper-V, it was not possible to resize a virtual hard disk attached to a running VM. Hyper-V Server 2012 R2 makes it possible to not only expand, but even reduce the size of the virtual disk (VHDX format only) without stopping the running VM. But you cannot compress an online VHD. Using System Center Virtual Machine Manager 2012 R2, Hyper-V Manager, or the command line using PowerShell, you can make all of these adjustments.

Storage Quality of Service (QoS)

Hyper-V Server 2012 R2 includes the ability to limit individual VMs to a specific level of I/O throughput. Initially with Hyper-V Server 2012 R2, the only number that really makes a difference is the maximum limit. The IOPS are measured by monitoring the actual disk rate to and from the attached virtual hard drives. If you have applications capable of consuming large amounts of I/O, you’ll want to consider this setting to ensure that a single I/O-hungry VM won’t starve neighbor VMs or take down the entire host

Shared VHDX

With Hyper-V Server 2012 R2, Windows guest clusters (think traditional Windows Server failover clustering but using a pair of VMs) no longer require an iSCSI or Fibre Channel SAN, but can be configured using commodity storage: namely a shared VHDX file stored on a Cluster Shared Volume. Note that while the clustered VMs can be live migrated as per usual, a live storage migration of the VHDX file requires one of the cluster nodes to be taken offline.

Live Virtual Machine Exporting and Cloning

With Hyper-V Server 2012, you need to stop a running VM before you can export or clone it. It’s simply not an option in production. Hyper-V Server 2012 R2 removes this restriction. It’s now possible to export or clone a running VM from System Center Virtual Machine Manager 2012 R2.

Hyper-V Replication Frequency Cycle

Hyper-V Replica in Windows Server 2012 provides a fixed replication interval of 5 minutes. That being said, you can’t replicate any faster, even if you have the hardware or infrastructure to support it. Also you cannot replicate any slower, even if you don’t need such frequent copies.  Now Hyper-V Server 2012 R2 supports more frequent (every 30 seconds) and not so frequent (every 15 minutes) replication. This will even support an intermittent connection.


Unitek Education Instructor Abu Z.Author Spotlight: Unitek Education Instructor Abu Z.
Abu Z, a computer science graduate, has been in the technology industry for more than eight years, with six years’ experience as a Microsoft Certified Trainer. Abu spent much of his technology training career in the United Kingdom with different Microsoft CPLS partners. Abu’s Microsoft certifications include: MCSE, MCSA, MCP, MCTS, and MCITP. He takes pride in preparing IT professionals to succeed.


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