diff --git a/kiwi/builder/disk.py b/kiwi/builder/disk.py
index a16797b8322..55a6771b4f4 100644
--- a/kiwi/builder/disk.py
+++ b/kiwi/builder/disk.py
@@ -374,8 +374,24 @@ def create_disk(self) -> Result:
                             device_map, luks_root
                         )
 
+                    # create system layout for root system
+                    device_map = self._create_system_instance(
+                        device_map, stack
+                    )
                     # build bootable disk
-                    self._process_build(device_map, disk)
+                    self._build_main_system(
+                        stack,
+                        device_map,
+                        disk,
+                        self.storage_map['system'],
+                        self.storage_map['system_boot'],
+                        self.storage_map['system_efi'],
+                        self.storage_map['system_spare'],
+                        self.storage_map['system_custom_parts'] or {},
+                        self.storage_map['luks_root'],
+                        self.storage_map['raid_root'],
+                        self.storage_map['integrity_root']
+                    )
 
         # store image bundle_format in result
         if self.bundle_format:
@@ -715,51 +731,6 @@ def _map_root_filesystem(
             )
         self.storage_map['system'] = filesystem
 
-    def _process_build(self, device_map: Dict, disk: Disk) -> None:
-        with ExitStack() as stack:
-            # create system layout for root system
-            device_map = self._create_system_instance(device_map, stack)
-
-            # representing the entire image system except for the boot/ area
-            # which could live on another part of the disk
-            system: Optional[Union[FileSystemBase, VolumeManagerBase]] = \
-                self.storage_map['system']
-
-            # an instance of a class with the sync_data capability
-            # representing the boot/ area of the disk if not part of
-            # system
-            system_boot: Optional[FileSystemBase] = \
-                self.storage_map['system_boot']
-
-            # an instance of a class with the sync_data capability
-            # representing the boot/efi area of the disk
-            system_efi: Optional[FileSystemBase] = \
-                self.storage_map['system_efi']
-
-            # an instance of a class with the sync_data capability
-            # representing the spare_part_mountpoint area of the disk
-            system_spare: Optional[FileSystemBase] = \
-                self.storage_map['system_spare']
-
-            # a dict of instances with the sync_data capability
-            # representing the custom partitions area of the disk
-            system_custom_parts: Dict[str, FileSystemBase] = \
-                self.storage_map['system_custom_parts'] or {}
-
-            self._build_main_system(
-                stack,
-                device_map,
-                disk,
-                system,
-                system_boot,
-                system_efi,
-                system_spare,
-                system_custom_parts,
-                self.storage_map['luks_root'],
-                self.storage_map['raid_root'],
-                self.storage_map['integrity_root']
-            )
-
     def _build_main_system(
         self,
         stack: ExitStack,