---
features:
  - |
    It is now possible to signal and perform an online volume size change
    as of the 2.51 microversion using the ``volume-extended`` external event.
    Nova will perform the volume extension so the host can detect its new size.
    It will also resize the device in QEMU so instance can detect
    the new disk size without rebooting.

    Currently only the libvirt compute driver with iSCSI and FC volumes
    supports the online volume size change.
  - |
    The 2.51 microversion exposes the ``events`` field in the response body for
    the ``GET /servers/{server_id}/os-instance-actions/{request_id}`` API. This
    is useful for API users to monitor when a volume extend operation completes
    for the given server instance. By default only users with the administrator
    role will be able to see event ``traceback`` details.
