Error on unsupported storage controller type

lib/vagrant/errors.rb

@@ -940,6 +940,10 @@ module Vagrant
       error_key(:virtualbox_disks_primary_not_found)
     end
 
+    class VirtualBoxDisksUnsupportedController < VagrantError
+      error_key(:virtualbox_disks_unsupported_controller)
+    end
+
     class VirtualBoxGuestPropertyNotFound < VagrantError
       error_key(:virtualbox_guest_property_not_found)
     end

plugins/providers/virtualbox/cap/configure_disks.rb

@@ -221,7 +221,7 @@ module VagrantPlugins
 
             dsk_info[:port] = next_available_port.to_s
             dsk_info[:device] = "0"
-          else
+          elsif controller.storage_bus == 'IDE'
             # IDE Controllers have primary/secondary devices, so find the first port
             # with an empty device
             (0..(controller.maxportcount-1)).each do |port|
@@ -238,6 +238,8 @@ module VagrantPlugins
                 dsk_info[:device] = "0"
               end
             end
+          else
+            raise Vagrant::Errors::VirtualBoxDisksUnsupportedController, controller_name: controller.name
           end
 
           if dsk_info[:port].to_s.empty?

templates/locales/en.yml

@@ -1683,16 +1683,19 @@ en:
         '%{storage_bus}', but no such controller was found. Please add the
         proper controller to your guest using provider-specific
         customizations.
-      virtualbox_disks_primary_not_found: |-
-        Vagrant was not able to detect a primary disk attached to the SATA
-        controller. Vagrant Disks requires that the primary disk be attached
-        to the first port of the SATA controller in order to manage it.
       virtualbox_disks_defined_exceed_limit: |-
         VirtualBox only allows up to %{limit} disks to be attached to a single
         guest using the %{storage_bus} controller, including the primary disk.
 
         Please ensure only up to %{limit} disks of type '%{type}' are
         configured for your guest.
+      virtualbox_disks_primary_not_found: |-
+        Vagrant was not able to detect a primary disk attached to the SATA
+        controller. Vagrant Disks requires that the primary disk be attached
+        to the first port of the SATA controller in order to manage it.
+      virtualbox_disks_unsupported_controller: |-
+        An disk operation was attempted on the controller '%{controller_name}',
+        but Vagrant doesn't support this type of disk controller.
       virtualbox_guest_property_not_found: |-
         Could not find a required VirtualBox guest property:
           %{guest_property}

test/unit/plugins/providers/virtualbox/cap/configure_disks_test.rb

@@ -348,6 +348,15 @@ describe VagrantPlugins::ProviderVirtualBox::Cap::ConfigureDisks do
         end
       end
     end
+
+    context "unsupported storage controller" do
+      let(:controller) { double("controller", name: "Adaptec ACB-4000A", storage_bus: "SASI") }
+
+      it "raises an error" do
+        expect { subject.get_next_port(machine, controller) }
+          .to raise_error(Vagrant::Errors::VirtualBoxDisksUnsupportedController)
+      end
+    end
   end
 
   describe "#resize_disk" do