diff --git a/subiquity/common/apidef.py b/subiquity/common/apidef.py
index 25280e47..2bc90502 100644
--- a/subiquity/common/apidef.py
+++ b/subiquity/common/apidef.py
@@ -258,6 +258,9 @@ class API:
             def GET() -> StorageResponseV2: ...
             def POST() -> StorageResponseV2: ...
 
+            class orig_config:
+                def GET() -> StorageResponseV2: ...
+
             class guided:
                 def GET() -> GuidedStorageResponseV2: ...
                 def POST(data: Payload[GuidedChoiceV2]) \
diff --git a/subiquity/models/filesystem.py b/subiquity/models/filesystem.py
index 9becc0c4..f949d08a 100644
--- a/subiquity/models/filesystem.py
+++ b/subiquity/models/filesystem.py
@@ -1041,6 +1041,16 @@ class FilesystemModel(object):
         self.grub = None
         self.guided_configuration = None
 
+    def get_orig_model(self):
+        # The purpose of this is to be able to answer arbitrary questions about
+        # the original state.  _orig_config plays a similar role, but is
+        # expressed in terms of curtin actions, which are not what we want to
+        # use on the V2 storage API.
+        orig_model = FilesystemModel(self.bootloader)
+        orig_model.target = self.target
+        orig_model.load_probe_data(self._probe_data)
+        return orig_model
+
     def load_server_data(self, status):
         log.debug('load_server_data %s', status)
         self._all_ids = set()
diff --git a/subiquity/server/controllers/filesystem.py b/subiquity/server/controllers/filesystem.py
index 74ed90a2..8267174f 100644
--- a/subiquity/server/controllers/filesystem.py
+++ b/subiquity/server/controllers/filesystem.py
@@ -373,19 +373,26 @@ class FilesystemController(SubiquityController, FilesystemManipulator):
                      for pa in self.model._partition_alignment_data.values()))
         return sizes.calculate_suggested_install_min(source_min, align)
 
-    async def v2_GET(self) -> StorageResponseV2:
-        disks = self.model._all(type='disk')
+    def get_v2_storage_response(self, model):
+        disks = model._all(type='disk')
+        minsize = self.calculate_suggested_install_min()
         return StorageResponseV2(
                 disks=[labels.for_client(d) for d in disks],
-                need_root=not self.model.is_root_mounted(),
-                need_boot=self.model.needs_bootloader_partition(),
-                install_minimum_size=self.calculate_suggested_install_min(),
+                need_root=not model.is_root_mounted(),
+                need_boot=model.needs_bootloader_partition(),
+                install_minimum_size=minsize,
                 )
 
+    async def v2_GET(self) -> StorageResponseV2:
+        return self.get_v2_storage_response(self.model)
+
     async def v2_POST(self) -> StorageResponseV2:
         await self.configured()
         return await self.v2_GET()
 
+    async def v2_orig_config_GET(self) -> StorageResponseV2:
+        return self.get_v2_storage_response(self.model.get_orig_model())
+
     async def v2_reset_POST(self) -> StorageResponseV2:
         log.info("Resetting Filesystem model")
         self.model.reset()
diff --git a/subiquity/tests/api/test_api.py b/subiquity/tests/api/test_api.py
index e1854c05..a9acdd5d 100755
--- a/subiquity/tests/api/test_api.py
+++ b/subiquity/tests/api/test_api.py
@@ -1101,6 +1101,22 @@ class TestPartitionTableEditing(TestAPI):
             self.assertEqual(-1, p3['estimated_min_size'])
             self.assertEqual(2 << 20, p4['estimated_min_size'])
 
+    @timeout()
+    async def test_v2_orig_config(self):
+        cfg = 'examples/win10-along-ubuntu.json'
+        extra = ['--storage-version', '2']
+        async with start_server(cfg, extra_args=extra) as inst:
+            start_resp = await inst.get('/storage/v2')
+            resp = await inst.get('/storage/v2/guided')
+            resize = match(resp['possible'],
+                           _type='GuidedStorageTargetResize')[0]
+            resize['new_size'] = 30 << 30
+            await inst.post('/storage/v2/guided', {'target': resize})
+            orig_config = await inst.get('/storage/v2/orig_config')
+            end_resp = await inst.get('/storage/v2')
+            self.assertEqual(start_resp, orig_config)
+            self.assertNotEqual(start_resp, end_resp)
+
 
 class TestGap(TestAPI):
     async def test_blank_disk_is_one_big_gap(self):