---
features:
  - |
    Image pre-caching on hosts by aggregate is now supported (where
    supported by the underlying virt driver) as of microversion
    2.81. A group of hosts within an aggregate can be compelled to
    fetch and cache a list of images to reduce time-to-boot
    latency. Adds the new API:

    * ``POST /os-aggregates/{aggregate_id}/images``

    which is controlled by the policy ``compute:aggregates:images`` rule.

    See the `[image_cache]/precache_concurrency` config option
    for more information about throttling this operation.
