VHD Native Boot – some gotchas to be aware of [update]

VHD native boot – the nice new feature in WS08R2 and Win7 that allows boot from VHD. It works, you can even boot from a VHD on USB external drive, which is nice, since normally Win does not allow boot from external USB (treats it as REMOVABLE and won’t install).

However there are 2 issues I met that were undocumented on the web:

  1. You cannot perform a BARE METAL backup of a WS08R2 machine running on VHD. I needed to do this to transfer a VHD from 1 hardware to a different one. Ooops – no option to do that:( And since this is a full fledged VM (SQL, Sharepoint etc) Sysprep is no option.
  2. If you want to move a native boot VHD to Hyper-V you need to:
    1. Mount the VHD, open the HKLM hive from that VHD in regedit (LOAD HIVE)
    2. go to CCS\Services\Intelide and change Startup to 0 (start on boot)
    3. Only then you will be able to boot a VM running on hyper-v with the VHD you used for native boot.

One more interesting thing my friend, Jakub, pointed me to: if you want to move the vhd from 1 hardware to another remember this:

bcdedit /set {guid} detecthal on (Refer to: http://technet.microsoft.com/en-us/library/dd799299(WS.10).aspx)

For most other issues you will find useful links on the web, e.g:



Nice link about doing vhd boot without any OS (note you can use normal windows 7/R2 installation dvd instead of WinPE): http://blogs.msdn.com/mikeormond/archive/2009/10/09/boot-windows-7-from-vhd-without-installing-a-native-os.aspx

And a step-by-step video: http://www.ditii.com/2009/10/19/native-boot-windows-7-windows-server-2008-r2-from-vhd-on-a-windows-xp-pc/2/

Any my friends step by step for booting vhd off usb (in PL though): http://app-v.spaces.live.com/Blog/cns!12E9A21E4AEEFADB!275.entry

SEARCH TAGS: bare metal backup native vhd boot, native vhd boot does not start in hyper-v


~ by alipka on February 18, 2010.

One Response to “VHD Native Boot – some gotchas to be aware of [update]”

  1. Well, I’ve tried and tried and tried and tried and tried! And I’m about to give up. I’d like to say it’s been worth it, but my personal experiences with native VHDs on bare metal have been pretty dire.

    I’ve learned:

    You can suffer from a failure to boot message, without making any changes to your OS/MFT/BCD/Hardware (unexplained, maybe “bad new SSD syndrome”)

    You can’t resize a native VHD (if it’s native you obviously need to be outside the VM, if your new shiny VHD file is the only file the only partition of your shiny new SSD, you CAN diskpart from a windows bootmedia, and if you attach the VHD you can shrink the volume therein, but the remaining unallocated space cannot be shifted to reduce the size of the VHD)

    (I think, ie it seems…) You CAN’T backup the native VHD (having shrank the volume but not the VHD, I resized the partition on the physical volume they’re stored on, to make room for ops, then from windows boot media went to cmd, and robocopied the (100gig) file. The good news was that a 25gig (expandable?) vhd was created, unfortunately the contents of the vhd are fudged; you’re asked to initialize the disk when attaching, leaving you with unallocated space…

    I wanted to create VHD backups, like system restore, but BETTER, then boot to my lightweight suite, or my full on (speech rec etc) power station, or my usual one, or maybe my testbed (for newbie apps)… maybe even a snowleopard and an android…. I never got close to adding a second bcd entry.

    Winblows. Still, and more so.

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