Reorder root disk as first disk in OSMorphing stage

coriolis/osmorphing/osmount/windows.py

@@ -213,7 +213,13 @@ def mount_os(self):
 
  for fs_root in [r for r in fs_roots if not r[:-1] == system_drive]:
  if self._conn.test_path("%sWindows\\System32" % fs_root):
- return fs_root, None
+ root_disk_id = None
+ root_disk_ids = self._get_disk_ids_from_drive_letters(
+ [fs_root.split(':')[0]])
+ if root_disk_ids:
+ root_disk_id = root_disk_ids[0]
+
+ return fs_root, root_disk_id
 
  raise exception.OperatingSystemNotFound("root partition not found")
 

coriolis/tasks/osmorphing_tasks.py

@@ -1,6 +1,8 @@
 # Copyright 2016 Cloudbase Solutions Srl
 # All Rights Reserved.
 
+import re
+
 from oslo_log import log as logging
 
 from coriolis import constants
@@ -14,6 +16,55 @@
 LOG = logging.getLogger(__name__)
 
 
+def _reorder_root_disk(volumes_info, root_device, os_type):
+ """
+ Reorders volumes_info so that the root disk will always be the first volume
+
+ root_device is returned by the OSMount Tools as the root partition device
+ (i.e. /dev/vdd2 for linux).
+
+ For Linux, we need to strip the trailing digits
+ to get the actual disk device. After that, we convert the last letter of
+ the disk device name into the equivalent index by alphabetical order.
+
+ Windows OSMount Tools should directly return the root disk index extracted
+ from diskpart (as string; i.e. '1').
+
+ Reordering is done by swapping the indexes of the volumes_info list.
+ """
+ if not root_device:
+ LOG.warn('os_root_dev was not returned by OSMount Tools. '
+ 'Skipping root disk reordering')
+ return
+
+ # the default disk device of the migrated VM should be /dev/Xdb, because
+ # /dev/Xda should be the worker's root disk. Same for Windows: Disk 0
+ # should be the worker's root disk, and Disk 1 the migrated VM's root disk
+ linux_root_default = 'b'
+ windows_root_default = 1
+
+ supported_os_types = [constants.OS_TYPE_LINUX, constants.OS_TYPE_WINDOWS]
+ if os_type == constants.OS_TYPE_LINUX:
+ pattern = r'[0-9]'
+ root_disk = re.sub(pattern, '', root_device)
+ disk_index = ord(root_disk[-1]) - ord(linux_root_default)
+ elif os_type == constants.OS_TYPE_WINDOWS:
+ disk_index = int(root_device) - windows_root_default
+ else:
+ LOG.warn('Root disk reordering only supported for %s. Got OS type: %s.'
+ 'Skipping root disk reordering', supported_os_types, os_type)
+ return
+
+ if disk_index > 0:
+ if disk_index < len(volumes_info):
+ volumes_info[0], volumes_info[disk_index] = (
+ volumes_info[disk_index], volumes_info[0])
+ else:
+ LOG.warn('Disk device name index out of range: %s for device %s'
+ 'Skipping root disk reordering', disk_index, root_device)
+
+
+
 class OSMorphingTask(base.TaskRunner):
 
  @classmethod
@@ -28,7 +79,7 @@ def get_required_task_info_properties(cls):
 
  @classmethod
  def get_returned_task_info_properties(cls):
- return []
+ return ["instance_deployment_info"]
 
  @classmethod
  def get_required_provider_types(cls):
@@ -53,13 +104,14 @@ def _run(self, ctxt, instance, origin, destination, task_info,
  osmorphing_connection_info = base.unmarshal_migr_conn_info(
  task_info['osmorphing_connection_info'])
  osmorphing_info = task_info.get('osmorphing_info', {})
+ instance_deployment_info = task_info.get('instance_deployment_info', {})
 
  user_scripts = task_info.get("user_scripts")
+ os_type = osmorphing_info.get("os_type")
  instance_script = None
  if user_scripts:
  instance_script = user_scripts.get("instances", {}).get(instance)
  if not instance_script:
- os_type = osmorphing_info.get("os_type")
  if os_type:
  instance_script = user_scripts.get(
  "global", {}).get(os_type)
@@ -72,7 +124,14 @@ def _run(self, ctxt, instance, origin, destination, task_info,
  instance_script,
  event_handler)
 
- return {}
+ volumes_info = instance_deployment_info.get('volumes_info', [])
+ LOG.debug('Volumes info before root disk reordering: %s', volumes_info)
+ _reorder_root_disk(volumes_info, osmorphing_info.get('os_root_dev'),
+ os_type)
+ LOG.debug('Volumes info after root disk reordering: %s', volumes_info)
+
+ return {
+ 'instance_deployment_info': instance_deployment_info}
 
 
 class DeployOSMorphingResourcesTask(base.TaskRunner):