Description of configuration options for rbd

Configuration option=Default value	Description
rbd_store_ceph_conf=	(StrOpt) Ceph configuration file path.
rbd_store_chunk_size=4	(IntOpt) Images will be chunked into objects of this size (in megabytes). For best performance, this should be a power of two.
rbd_store_pool=rbd	(StrOpt) RADOS pool in which images are stored.
rbd_store_user=None	(StrOpt) RADOS user to authenticate as (only applicable if using cephx.)