Use the spec's format for the volume instead of ext4
Use the spec's format for the volume instead of ext4

kunalkushwaha/openstorage,pault84/openstorage,libopenstorage/openstorage,pault84/openstorage,portworx/openstorage,libopenstorage/openstorage,jvinod/ost,libopenstorage/openstorage,ModelRocket/openstorage,pault84/openstorage,phoenix-io/openstorage,ModelRocket/openstorage