Help understand azurerm_backup_protected_vm

Terraform Providers Azure
1

I’m currently setting up a Recovery Services Vault which is responsible for VM backups. This is a partial config for one vm:

resource "azurerm_recovery_services_vault" "vm_backups" {
  name                          = "vm-backup-rsv-gwc-001"
  resource_group_name           = data.azurerm_resource_group.shared.name
  location                      = data.azurerm_resource_group.shared.location
  sku                           = "RS0"
  public_network_access_enabled = true
  # immutability                  = "Disabled"
  storage_mode_type            = "LocallyRedundant"
  cross_region_restore_enabled = false
  soft_delete_enabled          = true

  tags = {
    "TerraformManaged" = "true"
  }
}

data "azurerm_virtual_machine" "dev" {
  name                = "vm-dev-db2-gwc-001"
  resource_group_name = "mds-dev-gwc"
}

resource "azurerm_backup_policy_vm" "dev" {
  name                = "dev-vm-recovery-vault-policy"
  resource_group_name = azurerm_recovery_services_vault.vm_backups.resource_group_name
  recovery_vault_name = azurerm_recovery_services_vault.vm_backups.name
  policy_type         = "V2"
  timezone            = local.germany_timezone

  backup {
    frequency = "Daily"
    time      = "04:00"
  }

  retention_daily {
    count = 7 // this is the minimum
  }

  instant_restore_resource_group {
    prefix = "backup-gwc-"
  }
  instant_restore_retention_days = 1
}

resource "azurerm_backup_protected_vm" "dev" {
  resource_group_name = azurerm_recovery_services_vault.vm_backups.resource_group_name
  recovery_vault_name = azurerm_recovery_services_vault.vm_backups.name
  source_vm_id        = data.azurerm_virtual_machine.dev.id
  backup_policy_id    = azurerm_backup_policy_vm.dev.id
}

What’s is not clear to me is if all disks attached to the VM will be included in the backup or not?

In the docs of azurerm_backup_protected_vm I see those 2 parameters: exclude_disk_luns, include_disk_luns. But both are optional, therefore, if none is specifed what happens? How can I make sure I backup my VM including all the attached disks?

  • exclude_disk_luns - (Optional) A list of Disks’ Logical Unit Numbers(LUN) to be excluded for VM Protection.
  • include_disk_luns - (Optional) A list of Disks’ Logical Unit Numbers(LUN) to be included for VM Protection.

UPDATE:

I run a backup manually and it seems it includes all disk by default. However, I consider this is a good information to be mentioned on the resource page of azurerm_backup_protected_vm .