Review: Microsoft's Hyper-V puts VMWare and Linux on notice

Review: Microsoft's Hyper-V puts VMWare and Linux on notice

Summary: Linux aficionado Jason Perlow finds a lot to like in Microsoft's Hyper-V hypervisor. He goes so far as to christen Hyper-V the potential "killer app" for Windows Server 2008. Here's why Perlow thinks Hyper-V will give VMWare and Linux vendors a run for the money.


After his last foray into the “Linux guy reviews a Microsoft product” space, Jason Perlow is back -- this time to take a look at Microsoft’s Hyper-V, the hypervisor-based virtualization solution built into the newly released Windows Server 2008. Although Hyper-V is still in beta and isn't slated to ship in final form until the latter half of this year -- and will be missing a few previously-promised features by the time it does arrive -- it just might be the "killer app" for Windows Server, and one which will have Microsoft's competitors scrambling to keep up, Perlow claims.

Here he is, in his asbestos-lined underwear, awaiting the inevitable flames . Take it away, Jason:

I confess to being a virtualization junkie. I’ve been using VM technology on the x86 platform since 1999, when VMWare Workstation first came on the market with their first Linux release. Since then, I’ve worked with a number of virtualization products on the desktop and on the server, as well as in enterprise environments, particularly with VMWare’s ESX Server product, the current market leader in hypervisor-based paravirtualization solutions, as well as with Xen, the Open Source project that comprises the virtualization core of a number of Linux and Unix-based virtualization products and OSes, such as Citrix XenServer, Oracle VM, Sun xVM, Red Hat Enterprise Linux 5, and SuSE Linux Enterprise Server 10. Now I can add Microsoft's Hyper-V (the beta version in the final Windows 2008 Server bits) to my list.

Hyper-V, formerly known as “Viridian”, greatly differs from the virtualization product from Microsoft currently marketed as Microsoft Virtual Server in that it uses a hypervisor to provide hardware abstraction services to the OS environment and do resource allocation and partitioning. This differs from products such as Microsoft Virtual Server, VMWare Server and VMWare Workstation, Parallels, Linux KVM, and the recently Sun-acquired Virtualbox from Innotek use a technique known as host-based virtualization in which a host operating system such as Windows or Linux runs a subprocess provided by its native kernel called a Virtual Machine Monitor (VMM) to provide virtualization services such as a virtual CPU, memory and devices to a virtual machine. A hypervisor, on the other hand, is a thin abstraction layer which boots on the native hardware that performs some of the functions of an OS kernel, but abstracts much of what is needed to run multiple operating systems with their applications on top of it.

The advantages of hypervisor-based virtualization is that it tends to be faster and more enterprise scalable. The disadvantages are that hypervisors tend to be heavily hardware dependent and usually require hardware acceleration, such as Intel’s “VT” or AMD’s “Pacifica” extensions present in the latest Xeon and Opteron chips, such as it is with Hyper-V and Xen-based solutions, and require modified OS kernels and special paravirtualized device drivers to be run in the VM environment to facilitate enhanced I/O and networking performance.

VMWare’s ESX differs from Hyper-V and Xen in that it currently uses pure software based virtualization, so it doesn’t need the VT or Pacifica extensions. However, it has a much tighter environment as to what kind of hardware it can run on – the hypervisor has a limited device driver compatibility list and VMWare keeps its ESX hypervisor source code very close to the vest, so development goes at a much slower pace – SATA disk drives, which are now commonplace on commodity x86 server machines, are not currently supported in VMWare ESX 3. ESX Server also requires a special networked clustered file system known as VMFS to store the virtual machine images, and you have to dedicate a SAN-based LUN to it. Hyper-V, on the other hand, will run on any modern system that can run 64-bit Windows 2008, stores all its virtual machines on regular directories in NTFS, and provides third-party and built-in driver support by using what is referred to a “Parent” OS as a pass-thru mechanism. In Xen parlance, this is also referred to as “Domain 0”, where device and file system support is provided by the Linux kernel (or in the case of Sun xVM, Solaris) and Linux file systems such as ext3 and ReiserFS.

So let’s get down to the nitty gritty – installation, ease of use, and performance.

It should come as no surprise that Hyper-V’s architecture looks remarkably similar to Xen’s, as Microsoft and XenSource – now a part of Citrix Systems – embarked on a technology sharing partnership in 2006.

The only thing you need to do to use Hyper-V is do a default install of Windows Server 2008, which took about 20 minutes on my Opteron dual-core machine, then go to the Windows 2008 Server Manager and choose “Add New Role” and select “Hyper-V” server. After a few minutes of self configuration and a reboot, Hyper-V boots Server 2008 and you can now start provisioning new Virtual Machines using the Hyper-V Microsoft Management Console (MMC) snap-in tool.

After installing the virtual machine, which can be done via CD-ROM/DVD media or mounting an ISO file, you install the Integration Components (similar to VMWare’s tools) to provide enhanced networking and paravirtualized hardware support. For Windows guest OSes -- with the exception of Vista, which will not work with the Integration Tools yet but will run slower in full virtualization mode-- this is accomplished with a simple wizard and a reboot of the virtual machine.

Let’s start with the good points. Overall, and for what is currently a beta of a 1.0 release, I think Microsoft did a great job with the Hyper-V manager – console access to the VMs is nice and fast and VM performance is excellent, and the provisioning and setup process is wizard-based and straightforward. I’d currently say that from a polish and maturity standpoint, its management capabilities are definitely better than what is in Citrix XenServer 4.x, and way ahead of what currently exists in Red Hat Enterprise Linux or SuSE Linux Enterprise Server.

However, Hyper-V falls somewhat short when compared to the cluster management, automated VM migration/load balancing (“VMotion”) and HA capabilities built into ESX Server 3 and VirtualCenter 3. Of course, Hyper-V is free as a built-in feature in Server 2008 Standard (with a $30 dedicated version coming down the road) and ESX Server costs several thousand dollars per copy, depending on the features purchased, so on a pure bang per buck and ease of use basis, it beats ESX and dare I say it – the Xen solutions built into Linux distros – hands down.

The bad points – as of this writing, you can only run the Hyper-V manager on another Windows 2008 Server machine, In other words, if you want to remotely manage a Hyper-V box, even a stripped-down "Core Install" Hyper-V machine, you will need a Windows 2008 box with the full blown Windows 2008 stack installed. This will be solved when the regular workstation Windows 2008 administration tools, which include the Hyper-V Manager, now called RSAT (short for Remote Server Administration Tools) are finally released from beta testing, which should happen by March, according to Microsoft. The bad news is that they only run on Vista Service Pack (SP) 1.

It looks like that if you want to bring Server 2008 into your environment, you're currently stuck with Terminal Server RDP connections from XP workstations or resigning to at least bring in a few Vista machines to perform admin duty with RSAT. I really, really hope that this is something Microsoft plans to address soon -- because while Terminal Server is nice, you should just be able to remote console to the Virtual Machine directly from XP without requiring Vista or another remote access solution like VNC or virtualized Terminal Services -- as you can with the competing VMWare Virtual Infrastructure client or the Citrix XenCenter client.

As a result of Microsoft’s partnership with Citrix and XenSource, Microsoft also provides Integration Components for Linux OSes, which is currently a separate download that you need to register for on the Microsoft Connect beta testing site. Hyper-V’s integration tools will theoretically support any Linux operating system that has a paravirtualized Xen kernel available. At this time, only SuSE Linux Enterprise Server 10 is officially supported, but I was able to get it working just fine with the free OpenSUSE 10.3 and CentOS 5.1, a popular free Red Hat clone, both of which are Xen-enabled out of the box.

The installation process is a bit kludgy and not well scripted like VMWare’s tools currently are – it requires a manual installation of the Xen kernel, running a separate script that modifies the GRUB bootloader configuration to permit the use of Microsoft’s hypercall adapter, and then running the perl script to install the Integration Tools and paravirtualized drivers themselves. Once they are installed, Linux performance is indeed excellent and comparable to what you’d find in XenServer or any of the open-source Xen-based solutions.

In my opinion, Microsoft should release the Integration Components as Open Source, so that the various Linux distributions can provide native package feeds and native installer packages for their respective versions in order to simplify the installer process, which currently requires a number of developer package dependencies and the kernel headers and sources. All it should require to install this software should be a “yum install hyperv-components” or “apt-get install hyperv-components” (in Red Hat-, Debian- and Ubuntu-speak) and the package manager should install the new kernel, dependencies, GRUB config, hypercall adapter, and the pre-compiled modules.

Even though Hyper-V is still pre-1.0 code, I think Microsoft has done a bang-up job with its hypervisor, and it may just turn this Linux freak into a Windows 2008 junkie for running his own personal virtualization needs. While VMWare’s ESX is still superior on a number of fronts, including its aforementioned VMotion technology and its more powerful cluster management tools, Microsoft has certainly sent a major warning shot across its bow and the bows of the respective Linux vendors, as well.

If I were VMWare, I’d seriously look into open sourcing my hypervisor, engaging the community to get it entrenched into every environment possible – not just the Fortune 100 who have thousands of dollars per server to blow on a virtualization solution -- and focusing my efforts on support and value-add. Hyper-V represents the first stage of the mass-commodization of hypervisor technology, and if this beta release is any indication, it’s going to be a rough ride ahead for Microsoft's competitors. In fact, Hyper-V may be Server 2008’s “killer app” that the analysts have been looking for all this time.

Jason Perlow is a freelance writer and systems integration professional. He can be reached at jperlow at gmail dot com.


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


Mary Jo has covered the tech industry for 30 years for a variety of publications and Web sites, and is a frequent guest on radio, TV and podcasts, speaking about all things Microsoft-related. She is the author of Microsoft 2.0: How Microsoft plans to stay relevant in the post-Gates era (John Wiley & Sons, 2008).

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  • Proven Linux solution (VMware) Vs MS Windows Garbage (HV)

    You have the rock solid and proven Linux base that is VMWare vs the bug ridden and unreliable Windows base that is Hyper-V.

    Sorry, but if I'm putting my butt on the line with virtualization I'm going with the Reliabe Linux solution even if the others is free.

    Windows belongs nowhere, not everywhere.
    • proven vs. new: somebody probably thought this about Linux OS at one time

      But, wait, this is Microsoft product = automatically bad. The presence of Microsoft has never stopped us from using Linux (or Solaris) before in our mixed Linux/Windows environment. Sounds like we have more choices now, however good/bad they may be.
      • I question how "New" Hyper-V actually is

        While Microsoft has neither denied using Xen (as in open source Xen, not XenServer, which has proprietary modifications and is a commercial product) you do have to wonder why Hyper-V bares such a strong resemblance to Xen in terms of its actual architecture. Hypervisors take a long time to develop -- Xen and VMWare ESX took about 5 years before they got off the ground. I think that Hyper-V shares more Citrix XenServer (not Xen) code than MS is willing to admit. The product went from design to beta in less than 2 years since Xensource and Microsoft announced its partnership in August of 2006. I'm guessing they licensed a lot of the base level hypervisor stuff from XenSource and re-wrote the parent OS Domain 0 code to use Windows Server as the device driver pass-thru instead of Linux or Unix, and put a nice front-end on it so that RDP acts as a console for the video frame-buffer.
        • Ever heard of collaboration?

          Why presume it's a one way street? Note to the Linux world - not only is Linux not new but all new things originate from *nix-space.

          It never ceases to amaze me when zealots immediately presume that similarities stem from sharing designs and architectures rather than one party merely licensing or borrowing everything from the other?

          That's as dumb as believing that Micrsoft lifted the GUI from Apple - when in fact BOTH Microsoft and Apple lifted it from Xerox.
          • You misunderstand

            I actually think that Microsoft using the architecture of Xen is GOOD thing. They could have completely done this from scratch and spent a very long time re-inventing the wheel. Xen's technology is stable and well-architected. The fact that MS was able to get this product from concept to a polished beta in two years is testament to the fact they made a very good decision to partner with XenSource.
          • Jason:

            "I actually think that Microsoft using the architecture of Xen is GOOD thing."

            Yes, microsoft USING technologies that were developed by companies OTHER than MS is great, however, according to the MS Track Record, MS is not satisfied with just USING a technology... They must ABSORB and ASSIMILATE it like the Corporate BORG They are.

            "All your technology will be adapted to service... US!"
            --Loqutus of Borg

            Look at the origins of Microsoft's Virtual PC: Which is in fact Connectix Virtual PC for MAC- Which I have running, the very last version of, on my G4- And the interface is identical in every aspect to Microsoft Virtual PC.

            Way back when Bill Gates appropriated 86-DOS, backed by IBM to secure an OS for the brand new IBM PERSONAL COMPUTER... They were handing Gates the key to all future devepement on a platter, Silver.

            Gates even got his start by lying to MITS about develping his "Altair BASIC"

            It is one thing to have to use Microsoft products, but to applaud Gates for his strong-arm tactics of the last 3 decades is beyond belief.

            I am waiting for REACTOS to be developed further, so I can remove Microsoft products from my OS. But according to the last state of that fledgling OS, I have to way a while, cos installing the simplest program to that platform crashed it.
        • I question how "New" Hyper-V actually is

          Hyper-V is derived from the Virtual PC technology Microsoft acquired from Connectix. It is an enterprise solution thus it does need an management console. I doubt Microsoft ripped anyone off and before you make an accusation of such you really should make sure you can prove it.
    • Yeah let's judge it without even trying it

      VMWare may be better, but without trying Hyper-V how can you say that with certainty?

      It's okay to be skeptical (in fact, it's always healthy to be skeptical even if it does come from a source you trust), but to pass judgment without even trying it out passes more judgment on yourself than it does the product.
      Michael Kelly
      • Where have you been?

        Where have you been over the last 25 years. If you were using computers 25 years ago or more, you would know, without a doubt, that the first try with anything related to Microsoft turns out to be a golden turd. It almost always takes Microsoft 2 to 3 trys before they get it right.
        • Where have you been

          I agree. Microsoft has always had the "Get the customers to pay for us debugging our software" policy. The sell the software and a year later after all the customers are blue in the face with complaints, they release "Service Pack 1".

          We pay them money so they can get feedback off us for debugging their software.

          In my view, VMware has won. They got the virtualization thing sorted out ages ago. They are now just making the product better and better, and MS is still trying to get their platform to work!
      • RE: Yeah let's judge it without even trying it

        Just for the record not everyone has the time & resources to constantly experiment. We chose VMWare and expect to live with it until there's overwhelming evidence that there's something better. And that's obviously not the case.

        The other reason not to use MS is that they are already a large enough monopoly. For once we have an alternative. of the advantages of virtualization is that it saves our butt when MS produces unstable OSs. Why should I expect the very same company to suddenly write stable code?

        • You've always had and still have a choice

          "For once we have an alternative"

          You don't need to run Microsoft software or OS for anything. No one is forcing you to. As I've posted before, I run 100% of my consulting business on Linux, AIX, and Solaris.

          There are only two scenarios where I run Windows:

          1) if a customer requires me to use a Windows app and it can't run udner wine/crossover office (well it's just easier to boot a Windows VM anyways).

          2) when we choose to run Windows games

          In both cases, I can choose not to play a certain game or I can choose not to take the consulting engagement. But I still have a choice. Just like I require those that I use to sub-contract work or do work at my office to use an open document format and in order to logon to my network with their laptops, they need be able to logon to my OpenLDAP directory server or they don't get access.
          • RE: You've always had and still have a choice

            > You don't need to run Microsoft software or OS for anything.

            This is presumptuous and assumes you know our business requirements, vertical software requirements, etc. If only the business world was as black & white as you think it is.

          • It's Microsoft, that's all you need to know

            All they'll do is think that they're being clever and start *ucking around so that non-Windows stuff has problems. They'll leave that until they have what they think is a large enough install base to execute such nonsense.
          • RE: It's Microsoft, that's all you need to know

            Without a doubt...

          • Well it is, really

            No, I don't know *everyone's* business, and I should not have used such an absolute statement, but basic business needs are all met by alternatives to Windows and Windows based applications-especially office needs. As with all things, there are exceptions. Now, you may not like the alternatives for whatever reason, but they are there.

            As stated, not only do I not have to run any Windows or Windows-based app for my business, I know not a few that also have converted. Even Novell converted almost all of their corporate desktops to Linux-we're talking about several thousand desktops. The only ones that get a Windows desktop is if their job requires them to develop on it or some other reason, like something they do requires it. Novell found the same thing that many companies found, that most all of a company's business can be run on Linux. In Novell's case, they found that by 2005, only 20% of their desktops needed to be Windows, and indications are that that number is dwindling.

            As for vertical software, those types of software are so wierd that it is the number one reason why there is still NT 4 out there-some special app was never upgraded and it will only run on NT 4. I know this becuase the first systems I am asked to virtualize are the NT 4 boxes that must be kept up, for the reason above. I even did a P2V for a DOS application, yes, 16-bit MS-DOS application that this rather large costumer needed to continue to use and didn't want to look for an alternative. If someone would have told me I'd still be touching an MS-DOS system for a production system in 2007, I'd say they were crazy. But there is a lot of weird stuff out there.

            Are there alternatives to these? Many time there are but a company usually will not want to spend the money for converting, and we're talking about not just converting to a non-Microsoft solution but even converting to one that will run on more current versions of Windows.
          • I'd prefer Windows for two important reasons

            As a consultant, I understand many platforms, and I personally prefer Linux on my equipment. However, most of my revenue comes from Windows solutions.

            #1) Purchasing managers understand Windows. I have worked for many fortune 500 companies, and it is always easier to sell Windows solutions over others. IT managers seldom have IT degrees, and Windows is the only solution available that does not require technical babble to sell.

            #2) My custmers prefer and understand Windows solutions.

            Once non-windows solutions no longer require a new vocabulary, they will become more common place.
        • In other words, you refuse to pull your head out.

          Its ok, we understand.
          • RE: In other words

            > Its ok, we understand.

            Oh really? You know what vertical market applications we use? You know our customers and all the compatibility issues we have as a requirement? I suspect not.

      • Because of the architecture

        "..but without trying Hyper-V how can you say that with certainty?"

        If it is running on top of an OS, even using CPU virtual assist technology, as it is, it is fundamentally flawed and is no different than 5 or 6 other virtualization platforms-which all pale in comparison to bare metal virtualization as in ESX. That's just the way it is.

        So you may as well use the free VMware Server, or Linux KVM or Xen.

        When MS removes the OS and just has an hypervisor, then we can compare apples-to-apples.

        Right now it's just a lemon.