---
upgrade:
  - |
    'nova-manage db sync' can now sync the cell0 database.
    The cell0 db is required to store instances that cannot be scheduled to
    any cell. Before the 'db sync' command is called, the cell0 database
    must be created by the operator and a cell mapping for cell0 must be
    created using 'nova-manage cell_v2 map_cell0'.
    This command only needs to be called when upgrading to CellsV2.