Sunday 22 February 2009

Copying Hyper-V Disks

Copying virtual disks is something I do quite a lot of: I start with a base VM and then build out from there on distinct copies. Snapshots and differencing disks are supposed do this but my trust level isn't quite there yet ;-)
VPC 2007 makes it easy to find out where your disks live, pick them up, shift them around, and build new virtual machines around them. For some reason this doesn't seem like it's quite that simple with Hyper-V. Maybe that's because I was copying too much stuff (the snapshots folder and the Virtual Machines folder) and then creating a new VM pointing at the same location... dunno but it got messy yesterday with the copied disk and new VM never getting to the POST stage.

In an effort to remember how I got it right today, here's the very simple deal:
  • Locate the .vhd file to be copied
  • Create a new folder to contain the copy
  • Copy the .vhd file to the new folder
  • Create a new virtual machine that also lives in the same new folder and point it to the copied disk
Hmm... seems just like it used to with VPC!!!

Custom-Built Microsoft Office SharePoint Server 2007 Branded Sites and Webpart Development -


  1. so have you found this to work or not? - seen conflicting info on it

    here says no

    here says yes

  2. Yep, works beautifully on the same machine but I haven't tried moving .vhds to a different Hyper-V host. No issues with MAC addresses (yet) but I'm only to the point of cloning a single base VM thus far--not running those copies side-by-side. Interesting first link though!

  3. On our test bench, we clone and copy virtual drives and images almost daily. One of the first problems we encountered was the bulkiness of the export/import process within the Hyper-V manager. Manually coping is doable, but painful.

    One of my technical folks decided to build a quick little app which solved the problem nicely. It copies and/or links virtual machines while handling all of the nasty little security issues which seem to arise when making copies of virtual machines.

    I don’t know if it will help you out or not, but it is available at

  4. @Dave - Sweetness! Can't wait to give it a try!

  5. Good Morning!!! is one of the best informational websites of its kind. I enjoy reading it every day. All the best.


Spam comments will be deleted

Note: only a member of this blog may post a comment.