Differencing VHD and size

[dh2i-sam]

It looks like the hyperv provider does not allow differencing VHDX images to be created with a size specified.

I have a collection of "golden master" VHDX images that are relatively small, e.g. an Ubuntu image that is 8GB. Using PS scripts, I create VMs with differencing images based on the master images, and the differencing images are typically much larger, 64-128GB. Hyper-V most certainly allows this, at least on Windows Server 2022.

The hyperv provider would be more useful if it allowed this use case.

Terraform Version

Terraform v1.9.3
on windows_amd64
+ provider registry.terraform.io/taliesins/hyperv v1.2.1

Affected Resource(s)

• hyperv_vhd

Terraform Configuration Files

resource "hyperv_vhd" "web_server_vhd" {
  path = "c:\\web_server\\web_server_g2.vhdx"
  parent_path          = "C:\\Hyper-V\\BASE-JAMMY.vhdx"
  size = 10737418240 #10GB
}

Debug Output

│ Error: Conflicting configuration arguments
│
│   with hyperv_vhd.web_server_vhd,
│   on main.tf line 19, in resource "hyperv_vhd" "web_server_vhd":
│   19:   parent_path          = "C:\\Hyper-V\\BASE-JAMMY.vhdx"
│
│ "parent_path": conflicts with size
╵
╷
│ Error: Conflicting configuration arguments
│
│   with hyperv_vhd.web_server_vhd,
│   on main.tf line 20, in resource "hyperv_vhd" "web_server_vhd":
│   20:   size = 10737418240 #10GB
│
│ "size": conflicts with parent_path

Important Factoids

• Hyper-V on Windows Server 2022