old_contents: # Licensed under the Apache License, Version 2.0 (the "License"); you may
  # not use this file except in compliance with the License. You may obtain
  # a copy of the License at
  #
  #      http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  # License for the specific language governing permissions and limitations
  # under the License.
  
  import sys
  
  from nailgun.db import db
  from nailgun.extensions.volume_manager.models.node_volumes import NodeVolumes
  
  
  node_id = int(sys.argv[1])
  nv = db().query(NodeVolumes).filter(NodeVolumes.node_id == node_id).first()
  
  if not nv:
      raise Exception("No volumes info was found for node {0}".format(node_id))
  
  volumes = nv.volumes
  
  os_vg = next(disk for disk in volumes if 'id' in disk and disk['id'] == 'os')
  volumes = [disk for disk in volumes if 'id' not in disk or disk['id'] != 'os']
  
  for disk in volumes:
      disk_volumes = disk['volumes']
      disk['volumes'] = []
      for v in disk_volumes:
          if v['type'] == 'pv' and v['vg'] == 'os' and v['size'] > 0:
              for vv in os_vg['volumes']:
                  partition = {'name': vv['name'],
                               'size': vv['size'],
                               'type': 'partition',
                               'mount': vv['mount'],
                               'file_system': vv['file_system']}
                  disk['volumes'].append(partition)
          else:
              if v['type'] == 'lvm_meta_pool' or v['type'] == 'boot':
                  v['size'] = 0
              disk['volumes'].append(v)
  
  db().query(NodeVolumes).filter(NodeVolumes.node_id == node_id).update(
      {"volumes": volumes})
  db.commit()
  
new_contents: # Licensed under the Apache License, Version 2.0 (the "License"); you may
  # not use this file except in compliance with the License. You may obtain
  # a copy of the License at
  #
  #      http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  # License for the specific language governing permissions and limitations
  # under the License.
  
  import sys
  
  from nailgun.db import db
  from nailgun.extensions.volume_manager.models.node_volumes import NodeVolumes
  
  
  node_id = int(sys.argv[1])
  nv = db().query(NodeVolumes).filter(NodeVolumes.node_id == node_id).first()
  
  if not nv:
      raise Exception("No volumes info was found for node {0}".format(node_id))
  
  volumes = nv.volumes
  
  try:
      os_vg = next(
          disk for disk in volumes if 'id' in disk and disk['id'] == 'os')
  except StopIteration:
      sys.exit(0)
  volumes = [disk for disk in volumes if 'id' not in disk or disk['id'] != 'os']
  
  for disk in volumes:
      disk_volumes = disk['volumes']
      disk['volumes'] = []
      for v in disk_volumes:
          if v['type'] == 'pv' and v['vg'] == 'os' and v['size'] > 0:
              for vv in os_vg['volumes']:
                  partition = {'name': vv['name'],
                               'size': vv['size'],
                               'type': 'partition',
                               'mount': vv['mount'],
                               'file_system': vv['file_system']}
                  disk['volumes'].append(partition)
          else:
              if v['type'] == 'lvm_meta_pool' or v['type'] == 'boot':
                  v['size'] = 0
              disk['volumes'].append(v)
  
  db().query(NodeVolumes).filter(NodeVolumes.node_id == node_id).update(
      {"volumes": volumes})
  db.commit()
  
subject: Stop update of volume metadata gracefully if 'os' volume is not on LVM