Hyper-V R2: What's New?

ASPE IT Training Hyper-V R2: What's New? A WHITE PAPER PREPARED FOR ASPE BY TOM CARPENTER www.aspe-it.com toll-free: 877-800-5221

Hyper-V R2: What s New? Executive Summary This white paper provides an overview of the new features in Hyper-V R2 and how they may benefit implementing organizations. Hyper-V R2, which ships with Windows Server 2008 R2, adds several new and important features to Microsoft s virtualization solution. Live migration is introduced in this version, providing little to zero downtime for virtual machine moves from one Hyper-V host to another within a cluster. The supported logical processors quadruples from 16 to 64 and you can now hot add or hot remove storage to VMs. Memory can now be accessed more efficiently on hosts supporting second level address translation. Networking support is also enhanced through the use of virtual machine chimneys and support for jumbo frames. All of these new features are covered from a functionality and benefit perspective in this white paper. Introduction Microsoft s Hyper-V virtualization solution made tremendous leaps over its predecessor Virtual Server; however, it was still lacking several enterprise ready features available in the primary competing product, which was VMware ESX Server and Virtual Center 3.5. Since the release of Hyper-V, VMware has released a new version of their product, VSphere, that adds additional enhancements to their virtualization offerings; however, the majority of the newest features in VMware are only beneficial in very large deployments. With the new features in Hyper-V R2, small and medium deployments of between 1 and 50 hosts may choose to implement Hyper-V R2 instead of VMware or alongside it at the very least. This white paper explores these new features and the benefits they provide. Hyper-V R2 Distributions Like its predecessor, Hyper-V R2 comes in two distributions: Windows Server 2008 R2 with Hyper-V Hyper-V Server 2008 R2 Windows Server 2008 R2 with Hyper-V The version of Hyper-V most often implemented in organizations is the add-on to Windows Server 2008. Windows Server 2008 R2 also supports a Hyper-V add-on and this version is often simply called Hyper-V R2 to distinguish it from the initial Hyper-V release. If you ve licensed the Windows Server 2008 R2 operating system, you automatically have licenses to run Hyper-V R2. For this reason, Hyper-V R2 is often called a free virtualization solution; however, since it is only free on a licensed OS and the machine is usually dedicated to hosting virtual machines (VMs), it is a purchased solution. The Hyper-V R2 add-on to Windows Server 2008 R2 has different features depending on the edition of Windows Server 2008 R2 that you are running. Table 1 provides a summary of these feature differences and the features in Hyper-V Server 2008 R2. 2009 ASPE Page 1 of 5

Feature Hyper-V Server 2008 R2 Windows Server 2008 R2 Standard Windows Server 2008 R2 Enterprise or higher Host clustering Live migration Large memory support in the host OS (>32 gigabytes) Support for more than 4 processors in the host OS Local graphical user interface (GUI) Additional server roles, other than Hyper-V R2 supported Guest virtualization rights included in the host server license Application failover Table 1: Feature Comparison Among Hyper-V R2 Editions Hyper-V Server 2008 R2 Hyper-V Server 2008 R2 is a standalone implementation of the Hyper-V R2 solution. The server is basically a Windows Server 2008 R2 server core installation, which does not include the GUI tools. You can run open source Linux VMs on Hyper-V Server 2008 R2 without any licensing costs as all; however, running licensed operating systems will require the appropriate licenses for each guest VM. Microsoft recommends Hyper-V Server 2008 R2 for the following uses: Test and Development Server Consolidation Branch Office Consolidation Hosted Desktop Virtualization (VDI) It is important to remember that Hyper-V Server 2008 R2 is a standalone installation of the Hyper-V R2 solution; however, Windows Server 2008 R2 with Hyper-V requires the OS license for the Windows Server 2008 R2 operating system edition on which it runs. Performance Features Hyper-V R2 introduces two major new performance enhancing features including SLAT Improved Processor Support SLAT 2009 ASPE Page 2 of 5

Hyper-V R2 has support for Second Level Address Translation (SLAT). SLAT uses new features on Intel and AMD CPUs to improve VM performance while reducing the processing load of the Windows Hypervisor. On Intel processors, the technology that supports SLAT is called Extended Page Tables (EPT). On AMD processors, the technology is called Nested Page Tables (NPT). The SLAT solution implements a second level of memory paging below the x86 and x64 paging tables in newer processors. In Hyper-V R2 implementations, Intel or AMD hardware-based SLAT support improves performance. SLAT support is not required to install Hyper-V R2, though hardware-based virtualization (Intel-VT and AMD-V) is still required. BENEFIT: With SLAT, memory operations are more efficient and will increase overall performance on supported systems. Improved Processor Support Hyper-V R2 improves processor support from two perspectives. First, more physical processors can now be supported on the host OS. Second, CPU core parking can be used to consolidate processing onto as few cores as possible. Physical Processors Hyper-V R2 can support up to 64 cores. This would mean 16 quad-core processors in a single server. Few organizations have such equipment today, but the old limit of 16 cores was certainly too few for growth in the next few years. By 2012, we should begin to see 32-core servers commonly available. Additionally, each VM can now be assigned 4 virtual processors instead of only 2. CPU Core Parking CPU Core Parking allows Windows and Hyper-V R2 to consolidate processing onto the smallest number of possible processor cores. The inactive cores are then suspended. CPU Core Parking does not necessarily improve processing performance, but it does improve power saving performance. BENEFIT: The improved processor support will allow for more processors to be implemented, but will only use the cores needed for current operations. Availability Features One of the key areas of improvement in Hyper-V R2 is in the area of availability. Hyper-V R2 now implement Live Migration, which is comparable to VMware s VMotion. Dynamic VM storage features assist in providing high availability as well. Live Migration Live Migration gives the administrator the ability to move running VMs from one node of a failover cluster to another node without dropping network connections or creating downtime for the users. The Live Migration feature requires the failover clustering role to be added and configured on servers running Hyper-V R2. Shared storage, such as iscso or Fibre Channel SANs, 2009 ASPE Page 3 of 5

is also required by the clustering service. The virtual machines are stored in the shared storage area. The virtual machine state is managed by only one of the nodes in the cluster. A different node can take over the state of the VM because it has access to all VHDs (virtual hard disks) used by the VM. Live Migration does not allow moving more than one VM from one host to another (or one node to another) at the same time. Within a cluster, a single migration must complete before the next migration can be initiated. High Availability Live Migration can be considered a high availability feature. Clustering is used with Live Migration and VMs can be moved from one node to another with no perceivable down time. Another high availability feature is also available in Hyper-V R2 known as Dynamic VM Storage. Dynamic VM Storage Dynamic VM storage is another phrase for hot add or hot swappable drives. Hyper-V R2 introduces the ability to add storage to a VM while the VM is running. If the guest operating system is hot add aware, the new storage will become available without requiring a reboot. The ability to add storage without taking the server offline is a tremendous boost to availability for Hyper-V R2 VMs. BENEFIT: The new availability features in Hyper-V R2 mean that you can keep your virtual servers up and running longer and perform physical hardware maintenance without disrupting VM operations. Networking Enhancements The final area of enhancement that will be addressed in this white paper is networking. Two primary enhancements are included in the new Hyper-V R2 release: VM chimney and jumbo frame support. VM Chimney The support for chimney, also known as TCP Chimney Offload, is new in Hyper-V R2. VM Chimney is the offloading of all IP and TCP processing onto the NIC itself. Since the NIC is doing all the core IP and TCP work, the NIC receives the packets, processes the headers, generates any required acknowledgements, and maintains the state for the connection. When sending data, VM Chimney accepts a chunk of data from the application, fragments and packetizes it, generates the needed headers, performs the IP layer operations, and transmits the frame on the wire. The NIC must support TCP Chimney Offload in order to utilize this feature. Jumbo Frame Support Support for jumbo frames has been available in Windows Servers for several years. However, the virtual network stack in Hyper-V did not include support for these larger Ethernet frames. Hyper-V R2 adds support so that VMs may use jumbo frames. Jumbo frames can be up to 9,014 bytes in size in Hyper-V R2, but the underlying physical network must support it as well. 2009 ASPE Page 4 of 5

BENEFIT: With the networking enhancements in Hyper-V R2, newer network infrastructures can be utilized to pass more data across the network with less overhead. Additionally, networking operations will consume fewer CPU resources, freeing those CPUs for important VM operations. Summary Hyper-V R2 provides enhancements in the areas of performance, availability and networking that allow it to compete better in the marketplace, but - more importantly - they also meet the needs of Microsoft s customers. With Live Migration and networking enhancements, Hyper-V R2 is prepared to meet the needs of most small and medium virtualization deployments. 2009 ASPE Page 5 of 5