---
upgrade:
  - |
    After running the migration script to migrate CGs to
    generic volume groups, CG and group APIs work as follows.

    * Create CG only creates in the groups table.
    * Modify CG modifies in the CG table if the CG is in the
      CG table, otherwise it modifies in the groups table.
    * Delete CG deletes from the CG or the groups table
      depending on where the CG is.
    * List CG checks both CG and groups tables.
    * List CG Snapshots checks both the CG and the groups
      tables.
    * Show CG checks both tables.
    * Show CG Snapshot checks both tables.
    * Create CG Snapshot creates either in the CG or the groups
      table depending on where the CG is.
    * Create CG from Source creates in either the CG or the
      groups table depending on the source.
    * Create Volume adds the volume either to the CG or the
      group.
    * default_cgsnapshot_type is reserved for migrating CGs.
    * Group APIs will only write/read in/from the groups table.
    * Group APIs will not work on groups with default_cgsnapshot_type.
    * Groups with default_cgsnapshot_type can only be operated by
      CG APIs.
    * After CG tables are removed, we will allow default_cgsnapshot_type
      to be used by group APIs.