VM failed to start after deleting the Snapshot used to create the disk

Question

VM failed to start after deleting the Snapshot used to create the disk

Breno F 0

I created a VM based on a Snapshot of other machine. The VM was working and I saw the VM's disk consuming resources and the Snapshot as well. The disk is attached and the Create Option is FromImage, so I thought the Snapshot wasn't necessary any more considering that the disk has all the data. So I deleted the Snapshot and now I can't start the VM again.

"Failed to restart the virtual machine 'XXX'. Error: OS Provisioning for VM 'XXX' did not finish in the allotted time. However, the VM guest agent was detected running. This suggests the guest OS has not been properly prepared to be used as a VM image (with CreateOption=FromImage). To resolve this issue, either use the VHD as is with CreateOption=Attach or prepare it properly for use as an image"

Sudheer Reddy 2,075 Reputation points Moderator

2025-02-03T17:11:30.6566667+00:00

Hi Breno F,

Thank You for reaching out to Microsoft Q&A platform.

Which document are you referring and how you performed to create a snapshot, and also, can you please confirm which OS VM you are using. Could you please provide here, so that will better assist you on this.
Breno F 0 Reputation points

2025-02-03T17:20:10.16+00:00

Thanks for your first contact. I navigated to a VM, opened its disk and clicked on "Create snapshot". With this snapshot, I created a VM image and after I created a brand new VM from this image. It is a Windows Server 2016 VM. Everything went well and the new VM was working exactly as expected until I deleted the Snapshot file that started this process.
Sudheer Reddy 2,075 Reputation points Moderator

2025-02-04T10:12:05.4133333+00:00

Hi Breno F,

Thank You for the response.

The error seems like which was stated above can occur if the guest OS has not been generalized properly before creating an image from it.

If you have access to VHD, try to recreate it with CreateOption = Attach will resolve this issue.

https://learn.microsoft.com/en-us/azure/virtual-machines/capture-image-resource?toc=%2Fazure%2Fvirtual-machines%2Flinux%2Ftoc.json

https://learn.microsoft.com/en-us/azure/virtual-machines/attach-os-disk?tabs=portal#option-2-upload-a-specialized-vhd

Please check below community discussion documents for more information.

https://learn.microsoft.com/en-us/answers/questions/483128/getting-error-on-start-stop-of-vm-created-from-an

https://learn.microsoft.com/en-us/archive/msdn-technet-forums/1280ddbc-dca7-4b40-a0f8-66aa1152a57d.

If you have any queries, please let us know, we will help you.
Breno F 0 Reputation points

2025-02-04T14:24:53.0633333+00:00

I don't have access to the source VHD or Snapshot. My point is, the VM was 100% working and functional. I see the VM attached only to its current disk and it's working as well. When I go to the disk resource, I don't see anything depending on other resources (for instance the original Snapshot). Why the VM isn't working after deleting this source Snapshot if no component depends on it? How can I have my VM working again assuming that the VM and the disk are 100% functional and I don't have the original Snapshot anymore? Thank you again for your help.
Breno F 0 Reputation points

2025-02-04T14:26:31.2633333+00:00

I don't have access to the source VHD or Snapshot. My point is, the VM was 100% working and functional. I see the VM attached only to its current disk and it's working as well. When I go to the disk resource, I don't see anything depending on other resources (for instance the original Snapshot). Why the VM isn't working after deleting this source Snapshot if no component depends on it? How can I have my VM working again assuming that the VM and the disk are 100% functional and I don't have the original Snapshot anymore? Thank you again for your help.
Sudheer Reddy 2,075 Reputation points Moderator

2025-02-06T18:08:38.4133333+00:00

Hi Breno F,

Thanks for your update.

Could you please check in your resource group like have you deleted original VM disk or snapshot disk. Can you recheck once and let us know.
Breno F 0 Reputation points

2025-02-07T12:22:26.0066667+00:00

I haven't. I have only deleted the Snapshot which originated the new disk and VM. I'll try to replicate the error again step-by-step.
Sudheer Reddy 2,075 Reputation points Moderator

2025-02-10T17:05:18.3333333+00:00

Hi Breno F,

I'm curious to know if you've made any progress with replicating the scenario on your side. If you have any queries, please do let us know, we will help you.
Sudheer Reddy 2,075 Reputation points Moderator

2025-02-13T17:52:59.1333333+00:00

Hi Breno F,

I'm curious to know if you've made any progress with replicating the scenario on your side. If you have any queries, please do let us know, we will help you.