---
features:
  - |
    Add a new option of ``image_handler`` in the ``xenapi`` section for
    configuring the image handler plugin which will be used by XenServer
    to download or upload images. The value for this option should be a
    short name representing a supported handler.

    The following are the short names and description of the plugins which
    they represent:

    * ``direct_vhd``

      This plugin directly processes the VHD files in XenServer SR(Storage
      Repository). So this plugin only works when the host's SR type is
      file system based e.g. ext, nfs.  This is the default plugin.

    * ``vdi_local_dev``

      This plugin implements an image upload method which attaches the VDI
      as a local disk in the VM in which the OpenStack Compute service runs.
      It uploads the raw disk to glance when creating an image; When booting
      an instance from a glance image, it downloads the image and streams it
      into the disk which is attached to the compute VM.

    * ``vdi_remote_stream``

      This plugin implements an image proxy in nova compute service.

      For image upload, the proxy will export a data stream for a VDI from
      XenServer via the remote API supplied by XAPI; convert the stream
      to the image format supported by glance; and upload the image to glance.

      For image download, the proxy downloads an image stream from glance;
      extracts the data stream from the image stream; and then remotely
      imports the data stream to XenServer's VDI via the remote API supplied
      by XAPI.

      Note: Under this implementation, the image data may reside in one or
      more pieces of storage of various formats on the host, but the import
      and export operations interact with a single, proxied VDI object
      independent of the underlying structure.

deprecations:
  - |
    The ``image_upload_handler`` option in the ``xenserver`` conf section
    has been deprecated. Please use the new option of ``image_handler`` to
    configure the image handler which is used to download or upload images.