---
features:
  - |
    The compute manager now uses a local file to provide node uuid persistence
    to guard against problems with renamed services, among other things.
    Deployers wishing to ensure that *new* compute services get a predictable
    uuid before initial startup may provision that file and nova will use it,
    otherwise nova will generate and write one to a `compute_id` file in
    `CONF.state_path` the first time it starts up. Accidental renames of a
    compute node's hostname will be detected and the manager will exit to avoid
    database corruption. Note that none of this applies to Ironic computes, as
    they manage nodes and uuids differently.
upgrade:
  - |
    Existing compute nodes will, upon upgrade, persist the uuid of the compute
    node assigned to their hostname at first startup. Since this must match
    what is currently in the database, it is important to let nova provision
    this file from its database. Nova will only persist to a `compute_id` file
    in the `CONF.state_path` directory, which should already be writable.