virtual_machine_v2: VM creation fails with multiple NICs ("invalid input arguments")

[ec-mikacpe]

Nutanix Cluster Information

• Nutanix AOS: 7.3.0.6
• Prism Central: pc.7.3.0.6

---

Terraform Version

OpenTofu v1.9.0
on linux_amd64
+ provider registry.opentofu.org/hashicorp/template v2.2.0
+ provider registry.opentofu.org/nutanix/nutanix v2.3.1

---

Affected Resource(s)

• nutanix_virtual_machine_v2

---

Terraform Configuration Files

resource "nutanix_virtual_machine_v2" "vm" {
  for_each             = var.vms
  name                 = each.value.name
  description          = each.value.description
  num_cores_per_socket = each.value.num_cores_per_socket
  num_sockets          = each.value.num_sockets
  memory_size_bytes    = each.value.memory_gb * local.gib

  cluster {
    ext_id = data.nutanix_clusters_v2.clusters.cluster_entities[0].ext_id
  }

  # Boot disk
  disks {
    disk_address {
      bus_type = "SCSI"
      index    = 0
    }
    backing_info {
      vm_disk {
        disk_size_bytes = each.value.boot_disk_size_gb * local.gib
        data_source {
          reference {
            image_reference {
              image_ext_id = local.image_ext_id
            }
          }
        }
      }
    }
  }

  # Additional disks
  dynamic "disks" {
    for_each = each.value.additional_disks
    content {
      disk_address {
        bus_type = "SCSI"
        index    = disks.value.index
      }
      backing_info {
        vm_disk {
          disk_size_bytes = disks.value.size_gb * local.gib
          dynamic "storage_container" {
            for_each = var.storage_container_ext_id != null ? [var.storage_container_ext_id] : []
            content {
              ext_id = storage_container.value
            }
          }
        }
      }
    }
  }

  # Multiple NICs (fails during apply)
  nics {
    network_info {
      nic_type  = "NORMAL_NIC"
      vlan_mode = "ACCESS"
      subnet {
        ext_id = "BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"
      }
    }
  }

  nics {
    network_info {
      nic_type  = "NORMAL_NIC"
      vlan_mode = "ACCESS"
      subnet {
        ext_id = "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
      }
    }
  }

  boot_config {
    legacy_boot {
      boot_order = ["DISK", "CDROM", "NETWORK"]
    }
  }

  lifecycle {
    ignore_changes = [
      guest_customization,
      cd_roms,
      boot_config
    ]
  }
}

---

Debug Output

Gist: [https://gist.github.com/your-gist-link-here](https://gist.github.com/)

---

Panic Output

No panic output produced.

---

Expected Behavior

When multiple nics {} blocks are defined in the same nutanix_virtual_machine_v2 resource, Terraform / OpenTofu should successfully create a VM with all defined network interfaces attached to their respective subnets.

---

Actual Behavior

terraform plan displays both NICs correctly, but terraform apply fails with the following error for each VM:

plan:

      + nics {
          + ext_id = (known after apply)

          + backing_info {
              + is_connected = true
              + mac_address  = (known after apply)
              + model        = (known after apply)
              + num_queues   = 1
            }

          + network_info {
              + network_function_nic_type = (known after apply)
              + nic_type                  = "NORMAL_NIC"
              + should_allow_unknown_macs = (known after apply)
              + trunked_vlans             = (known after apply)
              + vlan_mode                 = "ACCESS"

              + ipv4_config (known after apply)

              + ipv4_info (known after apply)

              + network_function_chain (known after apply)

              + subnet {
                  + ext_id = "AAAAAAAAAAAAAAAAAAAAAAAAAAAA"
                }
            }
        }
      + nics {
          + ext_id = (known after apply)

          + backing_info {
              + is_connected = true
              + mac_address  = (known after apply)
              + model        = (known after apply)
              + num_queues   = 1
            }

          + network_info {
              + network_function_nic_type = (known after apply)
              + nic_type                  = "NORMAL_NIC"
              + should_allow_unknown_macs = (known after apply)
              + trunked_vlans             = (known after apply)
              + vlan_mode                 = "ACCESS"

              + ipv4_config (known after apply)

              + ipv4_info (known after apply)

              + network_function_chain (known after apply)

              + subnet {
                  + ext_id = "BBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"
                }
            }
        }

Error: error waiting for virtual Machine (...) to create: error_detail: Failed to perform the operation 'NIC create' on the VM with UUID 'a113142a-360b-4eee-58f6-125703192663' and NIC with UUID '6f0a61d6-a037-49de-a857-a98883374305' due to invalid input arguments., progress_message: 100

The same configuration with only one nics {} block works perfectly.
Adding a second nics {} block — even with identical parameters — consistently fails with invalid input arguments.

---

Steps to Reproduce

1. Define a VM with one NIC → terraform apply works correctly.
2. Add a second nics {} block (either same subnet or different).
3. Run terraform plan → plan shows both NICs correctly.
4. Run terraform apply → creation fails with error_detail: Failed to perform the operation 'NIC create' ... invalid input arguments.

---

Important Factors

• Using Prism Central API endpoint
• Subnets are valid and on the same cluster
• The same configuration works with a single NIC block
• Attempted both with and without backing_info

---

References

• Possibly related to the previous issue: [#993](nutanix_virtual_machine_v2 - change existing VM's NIC subnet (subnet.ext_id) is not possible #993)
• Provider documentation: [nutanix_virtual_machine_v2](https://registry.terraform.io/providers/nutanix/nutanix/latest/docs/resources/virtual_machine_v2)

---

Probably I try to configure it in the wrong way. In that case, please let me know the right way + update the documentation.

Thank you very much,

Best Regards,
Peter