Hyper-V: The no-brainer virtualization stack for Windows

Hyper-V: The no-brainer virtualization stack for Windows

Summary: Last Thursday, Microsoft released the final version of Hyper-V, the much anticipated built-in hypervisor for Windows Server 2008. Back in February, we had a look at a late beta release, and we were quite impressed with the performance of the system and how easy it was to manage virtual machines.

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Last Thursday, Microsoft released the final version of Hyper-V, the much anticipated built-in hypervisor for Windows Server 2008. Back in February, we had a look at a late beta release, and we were quite impressed with the performance of the system and how easy it was to manage virtual machines. While the release version doesn't add any additional features that would put it on par with competitor VMWare's ESX and VI3 or Citrix XenServer (such as live migration, clustered filesystems, virtual desktop management or template provisioning) it does offer equivalent stability as well as superior performance to either of these two competing solutions, as well as a price point that is absolutely unbeatable -- free with the Windows Server 2008 OS.

hyperv1.jpg See also: Hyper-V release gallery

The release version of the software provides wide support for the latest patch levels of Microsoft Server and Desktop Windows versions using NT kernel technology, going back to Windows 2000 SP4, as well as providing support for the full spectrum of 64-bit Windows versions. In order to exact the best possible performance out of these guest operating systems, a set of "Integration Tools" are provided in the form of paravirtualized  device drivers for networking, display, mouse and I/O. A similar paravirtualization method is also used by competitor VMWare with guest-based "VMWare Tools" in order to provide enhanced virtual memory management, networking and display/mouse services, which has been released as Open Source as GPL free software. Currently two Linux distributions support VMWare's GPL Open VM Tools -- Debian Etch and OpenSUSE 11.

Click on the "Read the rest of this entry" link below for more.

The Hyper-V install itself was fairly straightforward -- after installing the release version of the Hyper-V patch in Windows Server 2008 x64 (the software requires Intel VT or AMD-V extensions in order to work, unlike VMWare's ESX, which can run on 32-bit or 64-bit hardware and only makes partial use of the instruction set to provide 64-bit guest support) I added the Hyper-V role with the Server Manager tool, answered a few questions in a configuration wizard, and rebooted the system. Within minutes, I was installing virtual machines.

If you've already made an investment in Microsoft Virtual Server, your Windows guest VM's are easily portable, since they use the same file format, VHD. However, if you're a VMWare shop, converting VMDK files over to the native VHD format isn't something that can be done within the native Hyper-V interface. Instead, you'll want to download a copy of Microsoft System Center Virtual Machine Manager 2008 which is currently in open beta testing. This product includes the quick provisioning/templating capabilities, access controls for enforcing virtualization management policy, Physical-to-Virtual (P2V) conversion and advanced high availability cluster management that you're used to from competing products such as VirtualCenter and XenCenter. Microsoft VMM 2008 boasts the capability to seamlessly manage both VMWare ESX and Hyper-V environments, so that you don't have to silo your virtualization stacks with separate tools. However, you'll need to join your Hyper-V servers to an Active Directory domain and run a dedicated system for VMM as well as for SQL Server 2005 -- the beta we tried didn't like co-existing on the same test machine as our Hyper-V box.

Hyper-V Manager alone as a management tool is fairly spartan compared to either the VMWare Virtual Infrastructure Client or XenCenter, but for a first release, its got more than enough configuration options to get by. Virtual networks are easy to set up, the guest configuration settings are easily accessible and saving and restoring guest snapshot states is practically child's play. We would have liked to have seen something comparable to the VMWare Infrastructure Web Access that is in VMWare Server 2.0 and in ESX 3 as an installable option, but we can understand why Microsoft chose a native Win32 tool as opposed to having to run a web server stack with complex back-end  .NET components just to administrate a hypervisor.

Unfortunately, Hyper-V Manager can only run natively in Windows Server 2008 (32-bit or 64-bit) or on Vista SP1, so you will either need to administrate it from a few token Vista machines using the RSAT tools, via RDP connection, or directly from the Windows Server 2008 server console itself. RDP from a Terminal Server client itself is fine, as screen performance and response time is very good and runs even on Open Source Oses. However, RDP is infuriating to work from while a guest OS is being installed for the first time. For some odd reason, Hyper-V actually prevents you from using a mouse in a guest console window until the Integration Tools are actually installed, so you'll have to be skilled in using the <TAB> key when installing a guest from remote if you keep XP or Linux at your desk. Hopefully, your datacenter uses IP KVM infrastructure if you don't want to stand up a Vista system or another copy of Server 2008 on your desk to administrate your remote boxes for those times you do a guest install from scratch.

Once the Integration Tools are set up, however, we loved the near-native performance of Windows guests in Hyper-V, when using both the Hyper-V manager over RDP or connecting to a Windows guest after enabling Remote Desktop Connection and Terminal Services on the VM. SuSE Linux 10 performance was also very good, once the native hypercall adapter software (which translates low-level Xen calls to Hyper-V calls at the hypervisor level to provide paravirtualization for the kernel device drivers) and the Xen kernel was installed.

Microsoft and Citrix/Xensource are currently working on merging the code additions from the Hypercall Adapter into the upstream Linux Xen Kernel, so that in the future, a separate Hypercall Adapter will not be necessary for Linux. Microsoft has also released the Hypercall Adapter into GPL, so both community and commercial Linux distributions will be able to take advantage of Hyper-V, and for this I applaud them. Hopefully in the very near future, other Linux distributions besdies SLES will package a precompiled Hypercall Adapter into their repositories and install media, so that manual installation will no longer be necessary.

For an initial release, Hyper-V provides a no-brainer high-performance means of virtualizing Wintel guests, and I recommend it highly for enterprises looking for an affordable solution to increasing their virtual infrastructure. Microsoft faces a few challenges in getting crossover customers from the VMWare faithful, but in the end, its zero cost of entry is going to gain it a lot of initial early adopters who have no such loyalties. For the time being, at least until the Hypercall Adapter gets more love from other Linux distributions or the Xen kernel gets the needed Hyper-V modifications accepted upstream, VMWare and XenServer are still better solutions for bare metal Linux virtualization, unless of course SLES 10 is your chosen Linux platform, in which case I recommend it wholeheartedly.

What's your experience been with Hyper-V? Talk Back and let me know.

Topics: Microsoft, CXO, VMware, Virtualization, Storage, Software, Servers, Operating Systems, Open Source, Linux, Hardware, Cloud, Windows

About

Jason Perlow, Sr. Technology Editor at ZDNet, is a technologist with over two decades of experience integrating large heterogeneous multi-vendor computing environments in Fortune 500 companies. Jason is currently a Partner Technology Strategist with Microsoft Corp. His expressed views do not necessarily represent those of his employer.

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Talkback

12 comments
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  • Windows.

    So do you have to run a full version of Windows and then on top of that run Hyper V and then on top of that run your guests?

    Or can Hyper V be installed bare metal?
    tymiles
    • Hyper-V sits under your guest OS

      Hyper-V is a layer that sits underneath your guest OS (between your physical hardware and your guest OS). It then communicates with the Host (Server 2008) OS via an insanely fast hardware-assisted communications channel for interactions with most "fast-path" hardware and devices etc. This means that the Hyper-V doesn't need a stack of its own proprietary drivers etc. like VMWare etc do and that if you have a Server 2008 driver for your given storage etc. devices then your guest OS' will see them as normal supported devices.

      Further, Server 2008 can expose attached storage devices to guest OS' in "pass-through" mode which gives you about 98% of the speed of native access! :)
      de-void-21165590650301806002836337787023
      • Passthrough/RDM

        Passthrough/Raw Device Mapping isn't just a suggestion, though. Microsoft has pretty much told me that in order to get that near-native IOPS, you want to use it. This presents some SAN partitioning challenges as you need 1 raw LUN per VM, but for those boxes that need it -- such as Exchange and SQL Server, it's a minor sacrifice.
        jperlow
  • RE: Hyper-V: The no-brainer virtualization stack for Windows

    It is possible to do a "bare" install of just the core functionality needed in Windows 2008 and Hyper-V, which is essentially the kernel, libraries, and minimal Windows interface (literally, just a VGA screen and a command prompt window). Effectively making it a headless box. This has to be done via a scripted install, however.
    jperlow
  • RE: Hyper-V: The no-brainer virtualization stack for Windows

    Yes. Install Windows 2008 Server Core and enable Hyper-V. Then all your guests are belong to you ;)
    de-void-21165590650301806002836337787023
  • Jason, do better research next time

    "Currently two Linux distributions support VMWare???s GPL Open VM Tools ??? Debian Etch and OpenSUSE 11."

    You need to add Gentoo to that list

    esearch open-vm-tools

    * app-emulation/open-vm-tools
    Latest version available: 0.0.20080414.87182
    Latest version installed: [ Not Installed ]
    Size of downloaded files: [no/bad digest]
    Homepage: http://open-vm-tools.sourceforge.net/
    Description: Opensourced tools for VMware guests
    License: LGPL-2
    Suicida|
    • Mea Culpa

      My research came directly from the OpenVMTools site, where they said that the only two distros they knew of using it was OpenSUSE and Etch.
      jperlow
  • RE: Hyper-V: The no-brainer virtualization stack for Windows

    "Microsoft has also released the Hypercall Adapter into GPL, so both community and commercial Linux distributions will be able to take advantage of Hyper-V, and for this I applaud them."

    Wow, I thought I would never see the day. Now if Microsoft would quit trying to force us onto Vista and 2008 (some of us have IA constraints) we might actually be able to give this a spin.
    Suicida|
  • free?

    While MS virtualization is free on the surface, there is a cost to monopolistic control of software. MS already owns too much of the entire software market, achieved all too often by giving it away for free (like this). So I see it as an advantage whenever I can find a way to use non-MS products. That's one of the reasons I'm using VMWare instead. Yes, I know VMWare is a bit of a monopoly themselves, but I see it as a lesser of two evils.

    Much thanks for the review.

    gary
    gdstark13
  • RE: Hyper-V: The no-brainer virtualization stack for Windows

    Hyper-v is not free.

    Hyper-V costs $999-$3999 + $28 depending on the version of Win2k8 you choose. Doesn't sound free to me.

    This creative pricing is too transparent to fool the companies buying the product. If hyper-v sells at all (which I doubt) it will NOT be because it's cheaper.

    ESXi (with more features) costs $495 for dual CPUs and does not require Win2k8 to run. Sorry MS you might have a hypervisor but a true bare-metal one it is not.

    And folks don't hold your breath for a $28 hypervisor from MS that doesn't need Windows 2008..it's not coming.
    virtualBull
    • $28 version

      "And folks don't hold your breath for a $28 hypervisor from MS that doesn't need Windows 2008..it's not coming."

      Support that, please.
      jperlow
  • RE: Hyper-V: The no-brainer virtualization stack for Windows

    I've been using Hyper-V for a few months now, very reliable and you don't need to run it on a SCSI system. I tried to install VMWare on a system with SATA drives, got it installed but VMWare didn't see any lun's for the vm's. Same config for Hyper-V and it works fine.
    It's funny the complaints about it running on top of Windows. VMWare is running behind the VM's so I don't see your point.
    I'm a VMWare and Hyper-V user. VMWare is more mature but MS will catch up soon.
    GScully