Hyper-V Type 1 or Type 2?

Discussion in 'Virtualization' started by Leica, Jan 5, 2013.

  1. Leica

    Leica MDL Member

    Nov 15, 2012
    128
    10
    10
    I am running Hyper-V on Windows Server 2012 and I like it so far. I like the dynamic memory!

    Anyway I keep reading that Hyper-V is a Type 1 hypervisor. But it runs under Windows Server! So how can it be?

    Please enlighten me! Thanks.
     
  2. sebus

    sebus MDL Guru

    Jul 23, 2008
    5,966
    1,821
    180
    That is why one does NOT need GUI (Hyper-V Server)
     
  3. Leica

    Leica MDL Member

    Nov 15, 2012
    128
    10
    10
    I did read the Wikipedia article. So once the Hyper-V role is installed and running, the Windows Server 2012 operating system migrates to a virtual machine without you even knowing? And that each time you turn on your computer and login you are inside a virtual machine? WTF? It sure doesn't feel like a virtual machine :(

    What about for Hyper-V for Windows 8? Does that also run as a Type 1 hypervisor? And so then the whole of Windows 8 is "virtualised"?

    Seems far fetched...
     
  4. dawson

    dawson MDL Novice

    Jun 1, 2009
    9
    1
    0
    Lecia, When you run a process, like internet explorer, data moves between conceptual layers of the OS/hardware.
    These layers (Roughly) would be going from the bottom to the top, Physical hardware inside your pc, next to the hardware abstraction layer (HAL), micro kernel, windows 32/64bit subsystem, then the running user process.

    A type 2 hypervisor runs much like any other application on a pc, having to pass though all the OS layers to get stuff done. This is not optimal.
    A type 1 hypervisor in replaces/expands the function of the HAL. Now virtual machines can interface directly to the hypervisor layer (which is just above the physical hardware), bypassing all the other OS layers they really don't want to deal with.

    Now to your question about is windows now "Virtualized, or am i inside a virtual machine" ? Not in the concept your thinking about, IE a VHD container and memory allocations or virtual CD-Roms. It is however virtualized in the sense that it has to talk to the hypervisor layer using the same protocols and methods any virtual machines would. No longer is a virtual machine running as a user process sitting on the very top of the conveptual OS layer system, now the virtual machines and you windows instance is sitting side by side above the hypervisor layer.

    Dawson
     
  5. Leica

    Leica MDL Member

    Nov 15, 2012
    128
    10
    10
    Dawson,

    Many thanks for the explanation. So the "host" Windows Server 2012 would be no faster and in fact run at the same speed as a "guest" Windows Server 2012 running in a Virtual Machine? Since both now talk to Hyper-V instead of HAL?

    Also can you please answer the my second question, is Hyper-V for Windows 8 also a Type 1 Hypervisor? Does it also replace HAL in Windows 8?

    Thanks.
     
  6. dawson

    dawson MDL Novice

    Jun 1, 2009
    9
    1
    0
    No, virtual machines do not perform as well as the native installed operating system, but virtual machines do perform better on type 1 than 2. Some reasons Guests do not run at the same speed as the host are due to inherent overheads in emulating/abstracting virtual hardware devices inside a running virtual machine, into real hardware calls. Some are to due with the native OS getting more direct access to low level drivers, such as the graphics adapter drivers. Some are even design issues. An example with the 2008 R2 design limitation was number of virtual processors being limited to 4. If you had a physical machine with 8 cores, a single virtual machine assigned 4 virtual processors would only be able to execute 4 threads at a time, leaving 4 of the 8 cores largely redundant. This limitation could be worked around of course. For a terminal server (which typically has many user applications all running at the same time) you could have 1 physical box with no virtualization and all 8 cores in use, or two virtual machines each with 4 cores...

    Yes, Hyper-v for windows is based on the same code base as 2012, thus is considered to be a type 1 hypervisor

    Regards
     
  7. Jacoub

    Jacoub MDL Member

    Aug 14, 2011
    107
    13
    10
    greetings
    apologies if this not the right place for this question or if it is been answered before!!!!:confused::confused::confused:
    How can I convert a Hyper-V machine type 2 "WS2012 Hyper-V" to VMware Workstation 9.0.1 maintaining activation information. i.e. converting .xml file to it is equivalent .vmc

    thanks a lot in advance
     
  8. sebus

    sebus MDL Guru

    Jul 23, 2008
    5,966
    1,821
    180
    Correct, VERY wrong place & thread. Go here and knock yourself out reading 600+ pages