paths.go
func serverVolumePath(dcid, srvid, volid string) string {
	return serverVolumeColPath(dcid, srvid) + slash(volid)
}
func serverVolumePath(dcid, srvid, volid string) string {
	return serverVolumeColPath(dcid, srvid) + slash(volid)
}
// server_volume_path returns the string   "/datacenters/<dcid>/servers/<srvid>/volumes/<volid>"