Creating a bootable VHD the easy way…continued

You might have read and tried the scripts from my first blog about creating a bootable vhd here, and in this blog post I’ll continue where I left with some information about my usage of difference discs and bootable vhd’s.

First of all I started by creating a bootable vhd with my script with the following options:

Name Type Size
Base2k8r2.vhd Expandable 80 000 Mb (Remember that you need this much free space on your disc even if the vhd doesn’t have the size from start)

This left me with a vhd-file that took about 7Gb on my internal disc. I restarted my machine to make sure that my bootable vhd was working correctly.

After the health-check and some customizations like folder options in explorer I opened up a command prompt and entered shutdown /r /f, this way I don’t have to enter a reason to restart my Windows Server 2008 R2 OS Blinkar

Back in Windows 7 I took these steps to create a difference disc to keep my base disc clean:

  1. Start a command prompt as Administrator
  2. Write BCDEDIT /v and hit enter
  3. You will see the boot entries and their GUIDs
  4. Write BCDEDIT /delete {guid to the entry with a the path to your bootable vhd}
    WARNING this will delete a boot entry, make sure you enter the GUID to the entry where the device/osdevice points the path of your bootable vhd. Entering the wrong guid could make your computer UNBOOTABLE.
  5. Write DiskPart and hit enter
  6. Enter CREATE VDISK FILE="<Path to difference vhd>" PARENT="<Path to parent vhd>"
    You must specify a valid folder name or you’ll get an error.
  7. Write SELECT VDISK FILE=”<Path to difference vhd>” and hit enter
  8. Write ATTACH VDISK and hit enter
  9. Write Exit and hit enter
  10. Write BCDBOOT <your assigned drive letter>:\Windows and hit enter
  11. If you write BCDEDIT /v and hit enter you should see a new boot entry that points to your new difference disc.
  12. Restart your machine and make sure that your bootable difference disc starts correctly.

When I get some time I’ll try to automate these steps into a handy batch-file or application. I hope you found this post interesting.



7 Replies to “Creating a bootable VHD the easy way…continued”

  1. Did you activate the windows server core before doing the diff disk? Does the diff then “remember” its activation from the parent. I had some issues with that when playing with hyper-v doing the same stuff.

    1. No, I haven’t activated my machine yet. I’m not sure that would pose a problem as long as the diff disc has the same name and SID as the parent, but I could very well be mistaken here as I’m into real deep waters even attempting to answer this without trying it out myself…

Leave a Reply

Your email address will not be published. Required fields are marked *


This site uses Akismet to reduce spam. Learn how your comment data is processed.