Clone VM's OS disk to use on another VM

Question

Hi,

I have a VM in Azure (myVM-001) joined on-prem ADDS, running WS2022.

I need to clone above VM to create new VM (myVM-002) also joined the same ADDS.

So far:

1. Created OS disk snapshot of myVM-001, and from that created myVM-002. Obviously myVM-002 in ADDS automatically got DNS name on myVM-001 - so that didn't work out
2. From the same snapshot created Managed Disk and deployed myVM-002 from it - the same situation as point 1 - didn't work out.
3. Created Gallery Image Version from OS disk myVM-001. While deploying myVM-002from this image, deployment failed telling me that image was not prepared correctly (although it created myVM-002). However, myVM-002 again shows as myVM-001.

I'm sure I'm not the first person trying to clone OS disk and create from it totally new VM.

What are the simple steps to achieve this?

Any help appreciated

Answer 1

Hi PT, welcome to MS Q&A

Before proceeding with any cloning methods, ensure that myVM-001 is sysprepped to generalize the OS and remove unique identifiers. This step is crucial to avoid conflicts with the domain.

Please check this doc to do this https://learn.microsoft.com/en-us/azure/virtual-machines/generalize

By running Sysprep on myVM-001 before cloning, you ensure that the cloned VM (myVM-002) will have a clean and generalized Windows installation, ready to be joined to the domain without conflicts. Always remember to run Sysprep before cloning any Windows VM, especially when dealing with domain-joined environments like Active Directory.

After this ,

1. Take a Snapshot of the OS Disk:
   • In the Azure portal, navigate to the disks associated with myVM-001.
   • Select the OS disk and create a snapshot from it.
2. Create a New Managed Disk from the Snapshot:
   • From the snapshot created in step 2, create a new managed disk.
   • Ensure that the disk is generalized and doesn't contain any specific configuration tied to myVM-001.
3. Deploy a New VM (myVM-002) from the Managed Disk:
   • Create a new VM (myVM-002) using the managed disk created in step 3.
   • During VM creation, specify the necessary configurations such as networking, storage, and resource group.
   • Join myVM-002 to the same on-prem ADDS as myVM-001 during the provisioning process.
4. Update VM Configuration:
   • Once myVM-002 is deployed, ensure that its computer name and IP address are unique and not conflicting with myVM-001 or any other existing resources in the network.
5. Verify DNS Settings and Active Directory Records:
   • Confirm that myVM-002 has the correct DNS settings pointing to your on-prem ADDS.
   • Update the DNS records in your on-prem ADDS with the new IP address and hostname of myVM-002.

Kindly check and let us know if any further questions

Please accept answer if it helps, Thanks!