Link to home
Start Free TrialLog in
Avatar of Rob Rudloff
Rob RudloffFlag for United States of America

asked on

Exported copy of a Hyper-V VM causes conflict with original


Using Hyper-V, I exported a user's VM and then imported it to create a copy in a new VM.  I used the "create a new unique ID" option.  (I should note that the Hyper-V server is at our office, these VM's are not on Azure or anything like that.)

(Names and IP's changed to protect the innocent ...)

I started the new VM and changed it's IP.  The original VM was and the new VM is   Both VM's are on our corporate domain.  The new VM was added to the domain and is listed on the DC as "NEWPC" and the old VM is "OLDPC".  I have already removed and re-added at least one of the VM's to the domain.

The VM called "NEWPC" is running fine, until I start "OLDPC" VM, at which point NEWPC start running slowly -- windows open slowly, and the remote users lose access to the VM intermittently.  Turn off OLDPC, and everything works fine on NEWPC.

I pinged them each with the other turned off, and all seems fine there, but there appears to be some other network conflict.  Any suggestions?



Avatar of Lee W, MVP
Lee W, MVP
Flag of United States of America image

So you essentially cloned an operating VM without using Sysprep?  

Hard to say what is wrong - I don't do things this way.  If I want to clone a system, I build it in audit mode, sysprep it, and then archive it for later use.  Or I install clean.

I'd start looking at event logs on both to see if there's anything there.

Might create a new VM using the old hard drive; but it could be a windows config issue.  You're not saying what OS you're running?  2008?  2012?  2016?  2019?  2022?  You MIGHT try running sysprep on the "new" vm to see if that helps; sysprep on production machines wasn't supported for a long time, but I do believe that changed in 2016 time frame.

Avatar of DEMAN-BARCELO (MVP) Thierry
Flag of France image

Link to home
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of Rob Rudloff


That's it! They do indeed have identical MAC addresses ...
I changed the MAC on one of the VM's and all is well now (at least so far ... it's been 4 hours).
Had to go to the Hyper-V server and change it there (not in the VM OS itself) see image below.
Merci !

User generated image

Note that you are in the settings of this specific VM (as I indicated to you). I did not say it was inside the VM.

You are NOT in the settings of the HyperV server it-self.