func cephRBDVolumeExists(clusterName string, poolName string, volumeName string,
	volumeType string, userName string) bool {
	_, err := shared.RunCommand(
		"rbd",
		"--id", userName,
		"--cluster", clusterName,
		"--pool", poolName,
		"image-meta",
		"list",
		fmt.Sprintf("%s_%s", volumeType, volumeName))
	if err != nil {
		return false
	}
	return true
}
func cephRBDVolumeExists(clusterName string, poolName string, volumeName string,
	volumeType string, userName string) bool {
	_, err := shared.RunCommand(
		"rbd",
		"--id", userName,
		"--cluster", clusterName,
		"--pool", poolName,
		"image-meta",
		"list",
		fmt.Sprintf("%s_%s", volumeType, volumeName))
	if err != nil {
		return false
	}
	return true
}
// cephRBDVolumeExists checks whether a given RBD storage volume exists.