'Removes the specified snapshot from Cinder management.
Does not delete the underlying backend storage object.
NOTE: We do set the expire countdown to 1 day. Once a snapshot is
unmanaged it will expire 24 hours later.'

def unmanage_snapshot(self, snapshot):

    with self._client.open_connection() as api:
        snapshot_id = snapshot.get('id')
        provider_id = snapshot.get('provider_id')
        volume_name = snapshot.get('volume_id')
        scvolume = api.find_volume(volume_name, provider_id)
        if (not scvolume):
            msg = (_('unmanage_snapshot:    Cannot    find    volume    id    %s') % volume_name)
            LOG.error(msg)
            raise exception.VolumeBackendAPIException(data=msg)
        screplay = api.find_replay(scvolume, snapshot_id)
        if (not screplay):
            msg = (_('unmanage_snapshot:    Cannot    find    snapshot    named    %s') % snapshot_id)
            LOG.error(msg)
            raise exception.VolumeBackendAPIException(data=msg)
        api.unmanage_replay(screplay)
