Add check os_location_data after root_type

install/variables/disk.py

@@ -610,6 +610,8 @@ class VariableOsLocationData(LocationHelper,TableVariable):
               "os_location_perform_format",
               "os_location_size"]
 
+    check_after = ["os_install_root_type"]
+
     def init(self):
         self.help = _("DISK bound for installation will be mounted to the "
                       "DIR directory. If set to 'none', the mount point will "