Hello,

We had a problem with some hardware on our Server 2012 Hyper-V and the server had to be rebuilt. I restored all the vhd and vhdx files and am having a problem when I recreate one of the VM's... the error I get it "Failed to add device 'Virtual Hard Disk' if I show details it says Failed to open attachment ' The file cannot be accessed by the system. This is only happening with one particular server, all the others had no problems. The server had 3 disks attached and I get the same error no matter which one I try and attach. Does anyone have any suggestions?

Thanks,

Gavin

• Edited by GavinRoss Wednesday, November 21, 2012 7:04 PM

Turns out I needed to turn on Deduping again, once it was turned back on the drives loaded.

• Marked as answer by Lawrence,Microsoft contingent staff, Moderator Thursday, November 22, 2012 7:37 AM

Hi,

Thanks for sharing your experience!

You experience and solution can help other community members facing similar problems.

Thanks for your contribution to Windows Server Forum!

Have a nice day!

Thanks, worked for me.  2012 R2

yes it works !

after removed data deduplication it gave me the error cannot be accessed by the system

disabled/enabled hyper-v ....nothing

reinstalled so ....nothing

give permission to .vhdx and .xml file  to the virtual machine id .....nothin

enabled again data deduplication and all worked....

very thanks

Great work, thank you.

I also had to enabled data deduplication (see here) to be able to import the old virtual machines.