# Storage Account
resource "azurerm_storage_account" "tf-sa-cluster-aos" {
  count=5
  name                     = "${lower(var.ax_base_hostname)}${count.index+1}stoacc"
  location                 = "${azurerm_resource_group.tf-rg-cluster-aos.location}"
  resource_group_name      = "${azurerm_resource_group.tf-rg-cluster-aos.name}"
  account_tier             = "${var.sto_acc_tier_std}"
  account_replication_type = "${var.sto_acc_rep_type_lrs}"

tags {
  environment = "${var.env}"
     }
}

Optional Managed Data Disk
resource "azurerm_managed_disk" "tf-mdsk-cluster" {
  count                = 5
  name                 = "${var.ax_base_hostname}-DATADISK-${count.index+1}"
  location             = "${azurerm_resource_group.tf-rg-cluster-aos.location}"
  resource_group_name  = "${azurerm_resource_group.tf-rg-cluster-aos.name}"
  storage_account_type = "Standard_LRS"
  create_option        = "Empty"
  disk_size_gb         = "2048"
}
resource "azurerm_virtual_machine" "tf-vm-cluster-aos" {
  count                 = 5
  name                  = "${var.ax_base_hostname}-${count.index+1}"
  location            = "${azurerm_resource_group.tf-rg-cluster-aos.location}"
  resource_group_name = "${azurerm_resource_group.tf-rg-cluster-aos.name}"
  availability_set_id   = "${azurerm_availability_set.tf-as-cluster-aos.id}"
  network_interface_ids = ["${element(azurerm_network_interface.tf-ni-cluster-aos.*.id, count.index+1)}"]
  vm_size               = "${var.ax_vm_size}"


 storage_data_disk {
   name            = "${element(azurerm_managed_disk.tf-mdsk-cluster.*.name, count.index+1)}"
   managed_disk_id = "${element(azurerm_managed_disk.tf-mdsk-cluster.*.id, count.index+1)}"
   create_option   = "Attach"
   lun             = 0
   disk_size_gb    = "${element(azurerm_managed_disk.tf-mdsk-cluster.*.disk_size_gb, count.index+1)}"
 }

}

Error: Unknown root level key: Optional



Error: resource 'azurerm_virtual_machine.tf-vm-cluster-aos' config: unknown resource 'azurerm_managed_disk.tf-mdsk-cluster' referenced in variable azu                    rerm_managed_disk.tf-mdsk-cluster.*.id



Error: resource 'azurerm_virtual_machine.tf-vm-cluster-aos' config: unknown resource 'azurerm_managed_disk.tf-mdsk-cluster' referenced in variable azu                    rerm_managed_disk.tf-mdsk-cluster.*.disk_size_gb



Error: resource 'azurerm_virtual_machine.tf-vm-cluster-aos' config: unknown resource 'azurerm_managed_disk.tf-mdsk-cluster' referenced in variable azu                    rerm_managed_disk.tf-mdsk-cluster.*.name