Eight Reasons to Run 7 XenDesktop on Hyper-V 2012 -
XenDesktop 7 is the latest version of Citrix product to deliver virtual desktops and applications enabling users to work anywhere on any device. XenDesktop 7 is supported on all major hypervisors; but I will present the case for the selection Hyper-V 2012. Please note that this will not be a Hyper-V vs. VMware or XenServer comparison hypervisor. Each hypervisor offers unique features that organizations need to decide which is most important to them. However Hyper-V 2012 offers some great improvements over Hyper-V 08 R2 to 7 XenDesktop deployments.
1. Support for Windows 8 and Windows 2012 virtual machines
2012 Hyper-V supports Windows 8 and Windows 2012 virtual machines. This may not be important for organizations with existing Windows 7 VDI deployments, but those running Windows XP must read. Microsoft announced that all support for Windows XP will end next year, 8 April 2014. In April 2013, Netmarketshare research shows that Windows XP is the second desktop operating system most widely used for companies with 38% market share. Windows 7 is in first place with a market share of 44%.
The Netmarketshare research also shows that over a period from September 2012 to April 2013, Windows 7 market share has remained steady at 44%. Windows XP market share fell from 41% to 38%, while Windows 8 increased from 0.8% to 3%. If the current trend continues, most organizations with deployments of Windows XP VDI will migrate to Windows 7 8. XenDesktop will support all Windows workstations versions from Windows XP to Windows 8, so that organizations can benefit party for migration, and continue to support legacy applications will not work on Windows 8.
2. SMB 3.0 Enhancements
the (SMB) Server Message Block protocol is used for sharing files in Windows. In Windows Server 2012, the SMB protocol has been updated with new features to improve performance and stability. Some of these new features have a direct impact on the performance of Provisioning Services (PVS) and Machine Creation Services (MCS).
SMB Direct is a new transport protocol that supports the network adapters that have access Remote Direct Memory (RDMA) capability. This allows direct memory data transfers memory between servers with minimal CPU utilization and low latency. For Hyper-V hosts in 2012, remote file servers appear as fast as local storage. By minimizing the use of Hyper-V processor is able to allocate more CPU cycles to virtual machines and applications.
SMB Multichannel is a new feature that allows bandwidth aggregation through multiple network interfaces. This improves machine performance Creation Services when virtual machines are placed on file shares with shared volumes in the cluster via SMB 3.0.
SMB Transparent Failover is another new feature that allows Windows file shares in a failover cluster configuration to be permanently available. A good example of this would be if a Provisioning Services vDisk is located on a file share in the cluster. If a failure occurs on the node, the SMB client on the provisioning server to reconnect to another file server node in the cluster automatically and Provisioning Services does not experience downtime.
For a deeper look at the new SMB 3.0 features please see the Microsoft TechEd 2013 session of Understanding Hyper-V over SMB scenario, Configuration and Performance End-to-End presented by Jose Barreto.
3. Improvements Extension
Hyper-V 2012 scale resources about 4-16 times higher than Hyper-V 08 R2. A Hyper-V host 2012 can support up to 320 logical processors, while a R2 Hyper-V host 08 supports 64. A host Hyper-V 2012 can support up to 4TB of RAM, while Hyper-V 08 R2 supports 1TB. A Hyper-V cluster 2012 can support up to 64 nodes, which goes well beyond the limitation of 16 knots Hyper-V 08 R2. For larger deployments with XenDesktop adequately sized servers, this means fewer physical resources in the data center to support the environment. See the table below from the Microsoft white paper on Windows Server 2012 to view other resource enhancements to Hyper-V, 2012.
4. Migration dynamic no longer limited to clusters
In Hyper-V 08 R2, Live Migration is only possible between nodes in a cluster. With Hyper-V 2012, it is now possible to "live migrate" between two autonomous Hyper-V hosts, or between two standalone Hyper-V host clusters. File shares in the storage locations must use SMB 3.0 to take advantage of this feature. This is useful for smaller XenDesktop environments where resources may be limited and dedicated host servers to a cluster may not be possible, or in test environments where building a cluster is not justified.
5. Network Enhancements
There have been several enhancements to Windows Server 2012 and Hyper-V networking 2012.
Logical Networks, a new feature in System Center virtual machine Manager SP1, you can create multiple virtual networks on a physical host for Hyper-V to isolate network traffic. To do this on Hyper-V 08 R2 VLANs are typically required. A design XenDesktop may require multiple VLANs to isolate virtual desktops, servers supporting infrastructure, and traffic Provisioning Services. Depending on the use case, using logical networks have a distinct advantage over VLANs. They do not have the complexity of the design of VLANs. They do not require a physical switch for isolating the flow, or require the use of VLAN tagging. VLANs are also limited to a single IP subnet that usually limit the creation of the virtual machine at one site. logical networks can be designed to extend through different IP networks. For more information about logical networks please see the Microsoft white paper on Windows Server 2012.
Virtual Fibre Channel is now supported which allows virtual machines to access Fibre Channel storage based directly. This feature is only available for virtual machines running the Windows Server operating system (Windows Server 08, 08 R2, and 2012). So while virtual desktops can not enjoy this, critical infrastructure servers supporting the XenDesktop environment can. The typical use case, when useful is when you use Failover Clustering and Live Migration.
NIC Teaming is now native in Windows Server 2012. Although it is possible to team NICs on a Hyper-V R2 host 08, requires the use of third party software and are not taken into supported by Microsoft. The Hyper-V Extensible Switch enables the Hyper-V host in 2012 to use the NIC teaming configurations in the operating system.
Single Route I / O Virtualization (SR-IOV) support is now available. This allows the functions of the physical network adapter is available directly on a virtual machine, which increases the network throughput and reduces the network latency. This feature is ideal for virtual servers Provisioning Services. By communicating with the network adapter directly Provisioning Services is able to perform and scale better. SR-IOV can also improve the performance of live migration.
6. Storage Enhancements
2012 Hyper-V supports 4K sector VHDs that replace the 512-byte sector disks as the new standard in the storage industry. Hyper-V 2012 also supports 512 sector byte emulation disks, also called of the 512th sector discs, which are disks that have a 512-byte logical sector size, but a physical sector size 4K . This allows support for existing software written for the discs of 512-byte sector which are incompatible with the 4K sector drives. There is a performance impact when using discs 512th due process "Read- modify-write "involved.
Hyper-V 2012 is a new format that VHDX greater protection against disk corruption due to power outages. The disc has a VHDX intent log that captures all changes to metastructure VHDX. If power is lost before the changes are written to disk, the changes are recovered from the intent log, once power is restored.
7. supply services 7 can broadcast on Hyper-V synthetic adapter
One of the limitations in the use of provisioning services 6.x on Hyper-V is that network adapter inherited Hyper-V is required to start and spread the vDisk to target devices. The legacy adapter performs at 100Mbps, so for VMs provisioned using the most efficient synthetic NIC, your option is to assign the adapters to both the network and synthetic inherited to the virtual machine. the streaming traffic is linked to the card of inheritance and other network traffic can run on synthetic adapter.
Provisioning Services 7 will support the distribution of traffic on the synthetic network adapter in Hyper-V (both 08 R2 and 2012 versions). The legacy adapter is always required to boot the virtual machine, about the first 20 MB, then after it starts to synthetic adapter as long as the two adapters are on the same subnet. This feature can be disabled via a registry setting if desired.
8. Auto Write Cache & BDM discs
When using Provisioning 7 services, creating the disk write cache is an automated step in the wizard Installation XenDesktop and the boot Device manager (BDM) disk if you prefer to start the virtual machines without using PXE services. (This feature is supported in Hyper-V 08 R2). You no longer need to build master model pictures with the disk write cache attached, and using the Boot Device Manager has been simplified greatly by eliminating the manual process involved in the partition configuration start-up.
For more information on all new features Hyper-V, 2012, please visit What's New in Microsoft Microsoft Hyper-V Server 2012 for more information about XenDesktop on Hyper 7 V, 2012, including architecture information, scalability and advice on improving performance, I encourage you to check the Microsoft TechEd Europe 2013 sessions presented by my colleague Tony Sanchez. Visit the Citrix Web site to download a XenDesktop evaluation 7.
Ed Duncan - Senior Consultant
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